lCondition2 - Index of

Parte lxxii 

Dos 

358 Dos: introduzione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 

358.1 Avvio del sistema . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 

358.2 Dispositivi secondo il Dos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 

358.3 Directory, file ed eseguibili . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 

358.4 Comandi e ambiente di avvio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 

358.5 Caratteri jolly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 

358.6 Invito dell’interprete dei comandi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 

358.7 Comandi interni principali . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 

358.8 Flussi standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 

358.9 Accesso diretto ai dispositivi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 

358.10 Riferimenti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 

359 Dos: dischi, file system, directory e file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

359.1 Suddivisione in partizioni . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

359.2 Inizializzazione di un’unità di memorizzazione . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

359.3 Etichetta di un’unità di memorizzazione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 

359.4 Analisi e correzione del file system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 

359.5 Copia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 

359.6 Trasferimento del sistema . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 

359.7 Modifica delle unità . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 

359.8 Altre particolarità . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 

360 Dos: configurazione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 

360.1 CONFIG.SYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 

360.2 AUTOEXEC.BAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

360.3 Comandi ridondanti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

360.4 Localizzazione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 

360.5 Orologio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 

361 Dos: script dell’interprete dei comandi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 

361.1 Parametri, variabili ed espansione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 

361.2 Chiamate di altri script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 

361.3 Strutture di controllo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 

361.4 Comandi utili negli script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 

362 Dos: gestione della memoria centrale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121 

83

362.1 Gestione particolare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 

362.2 Comandi appositi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 

362.3 Verifica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 

363 FreeDOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 

363.1 Installazione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123 

363.2 Impostazione e configurazione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 

363.3 RxDOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 

363.4 Riferimenti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 

364 Progetto GNUish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126 

364.1 Programmi di servizio vari . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 

364.2 Gnuplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 

364.3 Spreadsheet Calculator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

364.4 Ispell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

364.5 Perl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127 

364.6 Riferimenti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

365 The valuable DOS Freeware page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

365.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

365.2 OS and GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 

365.3 Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 

365.4 Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 

365.5 Compilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

365.6 Typesetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

365.7 More Dos software sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

365.8 Search engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

366 Clean the Clipper 5.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 

366.1 Step 1: try to compile with the /P parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 

366.2 Step 2: understand well the use of code blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 

366.3 Step 3: understand the object programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

366.4 Step 4: understand the get object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

366.5 Step 5: trying to stop using commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 

366.6 Step 6: free yourself from STD.CH - /U . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 

366.7 Step 7: take control over all include files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 

367 nanoBase 1997 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 

367.1 What is it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 

367.2 The dot command line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 

367.3 The menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 

367.4 The macro recording, compiling and execution . . . . . . . . . . . . . . . . . . . . . . . . . . . .161 

84

367.5 The report system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 

367.6 The integrated text editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

367.7 The internal documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

367.8 Download it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

367.9 Bugs and known problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 

368 nanoBase 1997 user manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 

368.1 Dos xBase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 

368.2 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 

368.3 How to use nB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 

368.4 Status line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 

368.5 The dot line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 

368.6 The menu system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 

368.7 The text editor DOC() . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

368.8 The help text file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

368.9 Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 

368.10 Data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 

368.11 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 

368.12 Delimiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 

368.13 Code blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 

368.14 Standard functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 

368.15 nB functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 

368.16 Normal command substitution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 

368.17 nB command substitution functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305 

368.18 RPT: the nB print function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 

368.19 How can I... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 

368.20 The source files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 

85

Dos: introduzione 

Capitolo 358 

DOS è acronimo di Disk Operating System e sta a indicare il nome di un sistema operativo per 

micro elaboratori basati su microprocessori i86, successore del vecchio CP/M. Probabilmente, 

data la sua estrema limitatezza, è un po’ azzardato voler parlare di «sistema operativo», tanto che 

qualcuno lo appella: «gestore di interruzioni» (interrupt). 

Questo sistema operativo nasce come software proprietario; tuttavia, attualmente il progetto più 

attivo attorno a questo tipo di sistema è FreeDOS, il cui scopo è quello di realizzarne un’edizione 

libera e completa. 

358.1 Avvio del sistema 

Un sistema Dos è composto essenzialmente da un kernel, un interprete dei comandi e da una 

serie di programmi di servizio. Questo concetto è analogo ai sistemi Unix, con la differenza che 

il kernel offre funzionalità molto scarse e solo per mezzo di interruzioni software (IRQ). 

Nelle versioni proprietarie del Dos, il kernel era suddiviso in due file, che raccoglievano funzionalità 

distinte in base all’importanza relativa. I nomi usati sono stati differenti e nel caso di 

FreeDOS il kernel è contenuto tutto in un solo file (tabella 358.1). 

Tabella 358.1. Comparazione tra i nomi dei file che compongono il kernel di un 

sistema Dos. 

Microsoft IBM Novell, Caldera RxDOS FreeDOS 

IO.SYS 

MSDOS.SYS 

IBMBIO.COM 

IBMDOS.COM 

IBMBIO.COM 

IBMDOS.COM 

RXDO- 

SBIO.SYS 

RXDOS.SYS 

KERNEL.SYS 

-- 

I file del kernel devono trovarsi nella directory radice della partizione o del dischetto per poter 

essere avviati. Per la precisione, l’avvio del kernel viene gestito direttamente dal codice inserito 

nel settore di avvio della partizione o del dischetto (512 Kibyte), che a sua volta viene avviato 

dal firmware (il BIOS, secondo la terminologia specifica dell’architettura i86 e successiva). 

Il kernel, dopo essere stato avviato, non attiva una procedura di avvio, ma si limita a interpretare 

uno script speciale, ‘CONFIG.SYS’, e subito dopo avvia l’interprete dei comandi, ovvero 

la shell. Tradizionalmente, il programma in questione è ‘COMMAND.COM’. Secondo la tradizione, 

l’interprete dei comandi che viene avviato dal kernel si occupa subito di eseguire lo script 

‘AUTOEXEC.BAT’. Gli script ‘CONFIG.SYS’ e ‘AUTOEXEC.BAT’ devono trovarsi nella directory 

radice del disco o della partizione da cui si avvia il sistema, ovvero quella in cui si trova già il 

kernel che viene avviato. 

L’interprete dei comandi, ‘COMMAND.COM’, è in grado di eseguire direttamente alcune funzionalità, 

attraverso comandi interni che non si traducono in programmi di servizio veri e propri. 

Tradizionalmente ‘COMMAND.COM’ si colloca nella directory radice del disco o della partizione 

in cui si trova il kernel stesso. Ciò non è propriamente indispensabile, ma conviene attenersi a 

questa linea per evitare fastidi inutili. 

86

Dos: introduzione 87 

358.2 Dispositivi secondo il Dos 

I dispositivi secondo il Dos hanno un nome, composto da lettere e cifre numeriche, terminato da 

due punti opzionali: 

nome_dispositivo[:] 

Il nome in questione può essere indicato utilizzando lettere maiuscole o minuscole, senza che la 

cosa faccia differenza. I nomi più comuni sono elencati nella tabella 358.2. È il caso di osservare 

che i due punti che concludono il nome, vanno usati necessariamente quando questo viene 

abbinato ad altre informazioni da cui non potrebbe essere distinto (per esempio un percorso). 

Tabella 358.2. Nomi dei dispositivi più comuni in Dos. 

Dispositivo Descrizione 

‘A:’ Disco nella prima unità a dischetti. 

‘B:’ Disco nella seconda unità a dischetti. 

‘C:’ Prima partizione Dos nel primo disco fisso. 

‘D:’, ‘E:’,... ‘Z:’ Partizione Dos o altro tipo di disco. 

‘CON:’ Console: tastiera e schermo. 

‘PRN:’ Porta stampante principale. 

‘LPT1:’, ‘LPT2:’,... Porte parallele. 

‘COM1:’, ‘COM2:’,... Porte seriali. 

Il Dos mantiene distinti i dischi e le partizioni, nel senso che questi non devono creare una 

struttura unica come avviene nei sistemi Unix. Pertanto, quando si fa riferimento a un percorso 

di un file o di una directory, si deve tenere in considerazione anche il disco o la partizione in cui 

si trova. 

Il modo utilizzato dal Dos per identificare i dischi e le partizioni, di fatto impedisce di accedere a 

questi dispositivi in modo indipendente dal file system sottostante. Per intenderci, l’«unità» ‘X:’ 

può essere una partizione Dos di un disco non meglio identificato; mentre non esiste un modo 

univoco per poter raggiungere il dispositivo fisico in cui si trova questo disco. 

358.3 Directory, file ed eseguibili 

Il Dos è nato dopo Unix e da questo sistema ha ereditato alcuni concetti elementari (forse troppo 

pochi). I percorsi di file e directory si separano con una barra obliqua, che però è inversa rispetto 

allo Unix. Anche con il Dos c’è una directory radice; tuttavia si aggiunge l’indicazione dell’unità 

di memorizzazione (il disco o la partizione). Si può osservare a questo proposito la figura 358.1. 

Figura 358.1. Struttura di un percorso in un file system Dos. 

C:\PRIMO\SECONDO\TERZO\QUARTO 

^ ^ ^ ^ ^ 

| | | | | 

| | | | file o directory finale 

| | | | 

| | | directory 

| | | 

| | separazione tra una directory e la successiva 

| | 

| directory radice 

| 

unità di memorizzazione

88 volume VIII Argomenti avanzati e accessori 

I nomi di file e directory possono essere indicati utilizzando lettere maiuscole o minuscole, senza 

che la cosa possa fare differenza. Questi nomi possono essere composti utilizzando anche cifre 

numeriche e altri simboli (che comunque è bene usare con parsimonia). 

Per la precisione, sono esclusi i simboli: ‘/’, ‘\’, ‘[’, ‘]’, ‘’, ‘+’, ‘=’, ‘;’, ‘:’, ‘,’, ‘?’, ‘*’, 

‘{’, ‘}’ e il punto che va usato esattamente come descritto nel seguito. 

Tradizionalmente, il Dos utilizza un tipo di file system elementare, denominato FAT (Dos-FAT), 

in cui i nomi dei file e delle directory possono essere composti utilizzando al massimo 11 caratteri, 

di cui otto compongono un prefisso e tre un suffisso. Il prefisso e il suffisso di questi nomi 

appaiono uniti attraverso un punto. Per esempio: ‘CIAO.COM’, ‘LETTERA.TXT’, ‘PIPPO.NB’,... 

Questa conformazione dei nomi è una caratteristica fondamentale del Dos, da cui derivano una 

serie di consuetudini e di limitazioni molto importanti. 

È importante osservare che non è opportuno che i nomi dei file coincidano con quelli dei dispositivi 

(senza i due punti finali). In pratica, non conviene creare file del tipo ‘CON:’, ‘PRN:’, 

ecc. Tutto dipende dal contesto, ma in generale è bene fare attenzione a questo particolare. 

Come nei sistemi Unix il Dos annovera il concetto di directory corrente, a cui si aggiunge il 

concetto di unità di memorizzazione corrente. Infatti, la directory va collocata in un disco o 

in una partizione. In base a questo principio, si possono indicare dei percorsi relativi, che fanno 

riferimento alla posizione corrente (nell’unità di memorizzazione corrente). Tuttavia, in più, 

ogni unità di memorizzazione ha una sua directory corrente. Per esempio, fare riferimento a un 

file in una certa unità di memorizzazione ‘x:’, senza specificare il percorso, significa indicare 

implicitamente la directory corrente di quella unità. 

Per esempio, supponendo che la directory corrente dell’unità ‘X:’ sia ‘X:\PRIMO\SECONDO\’, 

facendo riferimento al file ‘X:CIAO’, si intende indicare implicitamente il file ‘X:\PRIMO\ 

SECONDO\CIAO’. 

In un percorso si possono usare anche i simboli ‘.’ e ‘..’, con lo stesso significato che hanno in 

un sistema Unix: la directory stessa e la directory genitrice. 

Il file system tradizionale del Dos consente di annotare solo poche informazioni per i file e le 

directory: la data di modifica e quattro indicatori booleani, rappresentati da altrettante lettere: 

• H file o directory nascosti; 

• S file o directory di sistema; 

• R file o directory in sola lettura e non cancellabile; 

• A file o directory da archiviare (i dati sono stati modificati). 

Si tratta di attributi completamente differenti da quelli di Unix. Si può osservare in particolare la 

mancanza di un attributo che specifichi la possibilità di eseguire un programma o di attraversare 

una directory. Secondo la tradizione Dos, gli attributi vanno considerati nel modo seguente: 

• A viene attivato ogni volta che il file viene scritto o modificato e serve per automatizzare 

i sistemi di copia periodica; 

• R se attivo, il Dos non consente la scrittura o la rimozione;


• S se attivo si tratta di un file di «sistema», ma in pratica si comporta come l’attributo H; 

• H se attivo si tratta di un file «nascosto», che così non dovrebbe apparire nelle liste di file 

e directory. 

In generale, file e directory nascosti o di sistema non dovrebbero essere spostati fisicamente, 

nemmeno nell’ambito della stessa unità di memorizzazione. Questa esigenza nasce in particolare 

per i file del kernel, che non possono essere spostati se si vuole poter riavviare il sistema 

operativo. 

Dal momento che il file system non permette di determinare se un file è un eseguibile, l’unico 

modo per permettere al sistema di conoscere questa caratteristica sta nell’uso di suffissi convenzionali 

nei nomi: i file che terminano con l’estensione ‘.COM’ e ‘.EXE’ sono programmi binari 

(la differenza tra i due tipi di estensione riguarda il formato del binario); quelli che terminano per 

‘.BAT’ sono script dell’interprete dei comandi (‘COMMAND.COM’). 

La prima stranezza che deriva da questa caratteristica del Dos sta nel fatto che per avviare un 

eseguibile di questi, è sufficiente indicare il nome del file senza l’estensione, che diventa così 

un componente opzionale agli occhi dell’utilizzatore. 

358.4 Comandi e ambiente di avvio 

L’interprete dei comandi tradizionale dei sistemi Dos è il programma ‘COMMAND.COM’, che viene 

avviato direttamente dal kernel. ‘COMMAND.COM’ può essere avviato più volte successive, anche 

se di solito ciò è di scarsa utilità, dal momento che il Dos non è un sistema operativo in multiprogrammazione. 

In ogni caso, quando viene avviato dal kernel, si occupa di interpretare ed eseguire 

lo script ‘AUTOEXEC.BAT’ che si trova nella directory radice dell’unità di avvio. 

‘COMMAND.COM’ mostra un invito simile idealmente a quello delle shell Unix, dopo il quale possono 

essere inseriti i comandi. A loro volta, questi possono essere riferiti a comandi interni 

corrispondenti a funzionalità offerte direttamente dall’interprete, oppure possono rappresentare 

la richiesta di avvio di un programma esterno. 

Figura 358.2. Riga di comando. 

C:\>DIR A: /W 

^ ^ ^ ^ 

| | | | 

| | | opzione 

| | | 

| | argomento 

| | 

| comando 

| 

invito 

Il Dos ha ereditato da Unix anche il concetto di variabile di ambiente. Il meccanismo è lo stesso 

ed è fondamentale la variabile di ambiente ‘PATH’, con la quale si possono indicare i percorsi di 

ricerca degli eseguibili. Tuttavia, il Dos ha delle caratteristiche speciali, per cui, è il caso di fare 

alcuni esempi di comandi: 

• C:\>C:\PRIMO\SECONDO.EXE 

questo comando avvia l’esecuzione del file ‘C:\PRIMO\SECONDO.EXE’;


• C:\>C:\PRIMO\SECONDO 

questo comando potrebbe avviare l’esecuzione del primo dei file seguenti che riesce a 

trovare; 

– ‘C:\PRIMO\SECONDO.COM’ 

– ‘C:\PRIMO\SECONDO.EXE’ 

– ‘C:\PRIMO\SECONDO.BAT’ 

• C:\>SECONDO 

questo comando potrebbe avviare l’esecuzione del primo dei file seguenti che dovesse riuscire 

a trovare, ma in mancanza può continuare la ricerca nei percorsi indicati nella variabile 

di ambiente ‘PATH’. 

– ‘C:.\SECONDO.COM’ 

– ‘C:.\SECONDO.EXE’ 

– ‘C:.\SECONDO.BAT’ 

I percorsi indicati nella variabile di ambiente ‘PATH’ sono separati da un punto e virgola; per 

esempio: 

C:\;C:\DOS;C:\FDOS\BIN 

Di solito, il Dos dà per scontato che si cerchino gli eseguibili a cominciare dalla directory corrente. 

Per questo, occorre considerare che è sempre come se la variabile di ambiente ‘PATH’ 

contenesse questa indicazione prima delle altre: ‘.;C:\;C:\DOS;C:\FDOS\BIN’. È da osservare 

che FreeDOS si comporta in maniera differente, in quanto richiede espressamente 

questa indicazione della directory corrente. 

358.5 Caratteri jolly 

Il Dos imita l’utilizzo dei caratteri jolly come avviene nei sistemi Unix per opera delle shell. 

Tuttavia, nel Dos non si tratta di un’espansione che avviene per opera della shell, ma vi deve 

provvedere ogni programma per conto proprio. Questo rappresenta una gravissima deficienza del 

Dos, che però è irrimediabile. 

Su questa base, i comandi tendono a richiedere l’indicazione di un argomento che rappresenta il 

nome di uno o più file prima delle opzioni eventuali. 

Ma c’è un altro problema. Il punto che divide in due i nomi dei file e delle directory è un muro 

insuperabile per i caratteri jolly. 

I simboli che si possono utilizzare sono solo l’asterisco e il punto interrogativo. L’asterisco vale 

per una sequenza qualunque di caratteri, escluso il punto; il punto interrogativo vale per un 

carattere qualunque. 1 

1 Ci sono programmi di origine Unix, portati in Dos, che non hanno questa limitazione riferita al punto che separa 

l’estensione.


Modello 

Tabella 358.3. Alcuni esempi. 

Corrispondenza 

*.* Corrisponde a un nome qualunque. 

*.COM Un nome che termina con l’estensione ‘.COM’. 

CIAO.X?X 

Tutti i nomi che iniziano per ‘CIAO’ e hanno un’estensione composta da un lettera 

«X» iniziale e finale, senza specificare cosa ci sia al secondo posto. 

* Tutti i nomi che non hanno estensione (che non contengono il punto). 

358.6 Invito dell’interprete dei comandi 

Esiste un’altra variabile di ambiente fondamentale per il Dos. Si tratta di ‘PROMPT’, che consente 

di modificare l’aspetto dell’invito dell’interprete dei comandi. La cosa funziona un po’ come nelle 

shell Unix, per cui si assegna una stringa che può contenere dei simboli speciali, praticamente 

delle sequenze di escape che vengono espanse prima della visualizzazione. La tabella 358.4 riepiloga 

questi simboli particolari. In origine, il Dos mostrava in modo predefinito un invito simile 

all’esempio seguente, in cui appare solo l’unità di memorizzazione corrente: 

C:> 

Questo tipo di impostazione corrisponderebbe alla stringa ‘$N$G’. In seguito, si è passati a 

un invito simile al prossimo esempio, in cui si aggiunge anche l’informazione della directory 

corrente: 

C:\BIN\> 

Questo corrisponde alla stringa ‘$P$G’. 

Tabella 358.4. Sequenze di escape per definire dei componenti speciali all’interno di 

una stringa di invito. 

Simbolo 

Corrispondenza 

$Q = 

$$ $ 

$T Ora corrente. 

$D Data corrente. 

$V Numero della versione. 

$N Lettera dell’unità corrente. 

$G > 

$L < 

$B | 

$H (cancella il carattere precedente) 

$E (1B16) 

$_ Codice di interruzione di riga. 

Cancellando il contenuto della variabile di ambiente ‘PROMPT’ si ripristina la stringa di invito 

predefinita.


358.7 Comandi interni principali 

I comandi interni sono quelli che non corrispondono a programmi di servizio veri e propri, 

ma sono funzionalità svolte direttamente dall’interprete dei comandi. Nelle sezioni seguenti ne 

vengono descritti brevemente alcuni. 

358.7.1 CH, CHDIR 

CH [percorso] 

CHDIR [percorso] 

‘CH’, o ‘CHDIR’, è un comando interno dell’interprete dei comandi, che consente di visualizzare 

o di cambiare la directory corrente. È indifferente l’uso di ‘CD’ o di ‘CHDIR’; se il comando non 

è seguito dal percorso, si ottiene solo la visualizzazione della directory corrente. Si osservi che 

se si indica un percorso assoluto di unità di memorizzazione, se questa non corrisponde a quella 

attuale, si cambia la directory corrente di quella unità. 

Segue la descrizione di alcuni esempi. 

• C:\>CD 

Visualizza la directory corrente. 

• C:\>CD \TMP\LAVORO 

Sposta la directory corrente in ‘\TMP\LAVORO\’. 

• C:\TMP\LAVORO>CD DATI\LETTERE 

Sposta la directory corrente in ‘DATI\LETTERE\’ che a sua volta discende dalla posizione 

iniziale precedente. 

• C:\TMP\LAVORO\DATI\LETTERE>CD .. 

Sposta la directory corrente nella posizione della directory genitrice di quella iniziale. 

• C:\TMP\LAVORO\DATI>CD F:\TMP 

Cambia la directory corrente dell’unità ‘F:’, senza intervenire nell’unità corrente. 

358.7.2 X: 

{A|B| ...|Z}: 

Il Dos gestisce le unità di memorizzazione in modo speciale. Per cambiare l’unità di memorizzazione 

corrente, non esiste un comando analogo a ‘CD’: si deve indicare il nome dell’unità a cui si 

vuole accedere. 


• C:\>A: 

Cambia l’unità di memorizzazione attuale, facendola diventare ‘A:’.


• A:\>F: 

Cambia l’unità di memorizzazione attuale, facendola diventare ‘F:’. 

358.7.3 MD, MKDIR 

MD directory 

MKDIR directory 

‘MD’, o ‘MKDIR’, è un comando interno dell’interprete dei comandi, che consente di creare una 

directory vuota. 


• C:\>MD LAVORO 

Crea la directory ‘LAVORO\’ a partire da quella corrente. 

• C:\>MD \TMP\DATA 

Crea la directory ‘\TMP\DATA\’ nell’unità corrente. 

• C:\>MD F:\TMP\DATA 

Crea la directory ‘\TMP\DATA\’ nell’unità ‘F:’. 

358.7.4 RD, RMDIR 

RM directory 

RMDIR directory 

‘RD’, o ‘RMDIR’, è un comando interno dell’interprete dei comandi, che consente di cancellare 

una directory vuota. 


• C:\>RD LAVORO 

Cancella la directory ‘LAVORO\’ a partire da quella corrente. 

• C:\>RD \TMP\DATA 

Cancella la directory ‘\TMP\DATA\’ nell’unità corrente. 

• C:\>RD F:\TMP\DATA 

Cancella la directory ‘\TMP\DATA\’ nell’unità ‘F:’.


358.7.5 DIR 

DIR [directory|file] [/P] [/W] 

‘DIR’ è un comando interno dell’interprete dei comandi, che consente di visualizzare l’elenco del 

contenuto di una directory o l’elenco di un gruppo di file. L’argomento del comando può essere 

composto utilizzando caratteri jolly, secondo lo standard del Dos, ovvero i simboli ‘*’ e ‘?’. 

Tabella 358.5. Alcune opzioni. 

Opzione Descrizione 

Blocca lo scorrimento dell’elenco in attesa della pressione di 

/P 

un tasto quando questo è più lungo del numero di righe che 

possono apparire sullo schermo. 

Visualizza solo i nomi dei file e delle directory, senza altre 

/W 

informazioni, permettendo così di vedere più nomi assieme in 

un’unica schermata. 


• C:\>DIR *.* 

Visualizza l’elenco di tutti i file contenuti nella directory corrente. 

• C:\>DIR ESEMPIO.* 

Visualizza l’elenco di tutti i file il cui nome inizia per ‘ESEMPIO’ e continua con 

un’estensione qualunque. 

• C:\>DIR *.DOC 

Visualizza l’elenco di tutti i file il cui nome termina con l’estensione ‘.DOC’. 

• C:\>DIR F:\DOC\*.* 

Visualizza l’elenco di tutti i file contenuti nella directory ‘\DOC\’ dell’unità ‘F:’. 

• C:\>DIR F: 

Visualizza l’elenco di tutti i file contenuti nella directory corrente dell’unità ‘F:’. 

358.7.6 COPY 

COPY file_origine [file_destinazione] [opzioni] 

COPY file_1 + file_2 [+ ...] [file_destinazione] [opzioni] 

‘COPY’ è un comando interno dell’interprete dei comandi, che consente di copiare uno o più file 

(sono escluse le directory). Anche qui è consentito l’uso di caratteri jolly, ma al contrario dei 

sistemi Unix, i caratteri jolly possono essere usati anche nella destinazione. Il ‘COPY’ del Dos 

consente anche di unire assieme più file.




/V Fa in modo che venga verificato il risultato della copia. 

a sì che la copia avvenga in modo «binario». Questa opzione 

può servire quando si copia un file su un dispositivo e si 

/B 

vuole evitare che alcuni codici vengano interpretati in modo 

speciale. 

Non chiede conferma prima di sovrascrivere i file, se questi 

/Y 

esistono già nella destinazione. 


• C:\>COPY ESEMPIO PROVA 

Copia il file ‘ESEMPIO’ nella directory corrente ottenendo il file ‘PROVA’, sempre nella 

directory corrente. 

• C:\>COPY C:\DOS\*.* C:\TMP 

Copia tutto il contenuto della directory ‘\DOS\’ dell’unità ‘C:’ nella directory ‘\TMP\’ 

nella stessa unità ‘C:’, mantenendo gli stessi nomi. 

• C:\>COPY TESTA+CORPO+CODA LETTERA 

Copia, unendoli, i file ‘TESTA’, ‘CORPO’ e ‘CODA’, ottenendo il file ‘LETTERA’. 

• C:\>COPY *.DOC *.TXT 

Copia tutti i file che nella directory corrente hanno un nome che termina con l’estensione 

‘.DOC’, generando altrettanti file, con lo stesso prefisso, ma con l’estensione ‘.TXT’. 

• C:\>COPY PROVA.PRN PRN: /B 

Copia il file ‘PROVA.PRN’ nel dispositivo ‘PRN:’, ovvero sulla stampante, assicurandosi 

che la copia avvenga senza alterare alcunché. 

358.7.7 DEL, ERASE 

DEL file 

ERASE file 

‘DEL’, o ‘ERASE’, è un comando interno dell’interprete dei comandi, che consente di cancellare 

uno o più file (sono escluse le directory). È da considerare che i file che hanno l’attributo di sola 

lettura attivo, non possono essere modificati e nemmeno cancellati. 


• C:\TMP>DEL *.* 

Cancella tutti i file nella directory corrente. 

• C:\TMP>DEL ESEMPIO.* 

Cancella tutti i file contenuti nella directory corrente, il cui nome inizia per ‘ESEMPIO’ e 

termina con qualunque estensione.


• C:\TMP>DEL *.BAK 

Cancella tutti i file contenuti nella directory corrente, il cui nome termina con l’estensione 

‘.BAK’. 

358.7.8 REN, RENAME 

REN file_origine nome_nuovo 

RENAME file_origine nome_nuovo 

‘REN’, o ‘RENAME’, è un comando interno dell’interprete dei comandi, che consente di cambiare 

il nome di uno o più file (sono escluse le directory). Il primo argomento può essere un percorso 

relativo o assoluto, completo anche dell’indicazione dell’unità, mentre il secondo argomento è il 

nuovo nome, che implicitamente non può essere collocato altrove. 


• C:\>REN ESEMPIO PROVA 

Cambia il nome del file ‘ESEMPIO’, che si trova nella directory corrente, in ‘PROVA’. 

• C:\>REN *.TXT *.DOC 

Cambia il nome di tutti i file che, nella directory corrente, hanno l’estensione ‘.TXT’, 

trasformandoli in modo tale da avere un’estensione ‘.DOC’. 

358.7.9 SET 

SET [variabile_di_ambiente=stringa] 

‘SET’ è un comando interno dell’interprete dei comandi che ha lo scopo di assegnare un valore 

a una variabile di ambiente, oppure di leggere lo stato di tutte le variabili di ambiente esistenti. 

Quando si assegna un valore a una variabile, questa viene creata simultaneamente; quando non 

si assegna nulla a una variabile, la si elimina. 


• C:\>SET 

Elenca le variabili di ambiente esistenti assieme al loro valore. 

• C:\>SET PROMPT=$P$G$G 

Assegna alla variabile di ambiente ‘PROMPT’ la stringa ‘$P$G$G’. Questo si traduce nella 

modifica dell’aspetto dell’invito dell’interprete dei comandi. 

• C:\>SET PATH=.;C:\BIN;D:\BIN 

Assegna alla variabile di ambiente ‘PATH’ la stringa ‘.;C:\BIN;D:\BIN’. 

• C:\>SET PROMPT= 

Elimina la variabile di ambiente ‘PROMPT’, assegnandole la stringa nulla.


358.7.10 TYPE 

TYPE file 

‘TYPE’ è un comando interno dell’interprete dei comandi, che consente di leggere ed emettere 

il contenuto di un file attraverso lo standard output. Questo si traduce in pratica nella 

visualizzazione del file in questione. 


• C:\>TYPE LETTERA 

Emette il contenuto del file ‘LETTERA’ che si trova nella directory e nell’unità corrente. 

• C:\>TYPE C:\DOC\MANUALE 

Emette il contenuto del file ‘MANUALE’ che si trova nella directory ‘\DOC\’ dell’unità ‘C:’. 

358.8 Flussi standard 

Il Dos ha ereditato da Unix anche i concetti legati ai flussi standard. In pratica, i programmi 

hanno a disposizione tre flussi predefiniti: uno in lettura rappresentato dallo standard input, due 

in scrittura rappresentati dallo standard output e dallo standard error. Il meccanismo è lo stesso di 

Unix, anche se non funziona altrettanto bene; infatti, non è possibile ridirigere lo standard error 

attraverso l’interprete dei comandi. 

Secondo la tradizione delle shell Unix, la ridirezione dello standard output si ottiene con il simbolo 

‘>’ posto alla fine del comando interessato, seguito poi dal nome del file che si vuole generare 

in questo modo. Per esempio, 

C:\>TYPE LETTERA > PRN: 

invece di visualizzare il contenuto del file ‘LETTERA’, lo invia al dispositivo di stampa 

corrispondente al nome ‘PRN:’; inoltre, 

C:\>DIR *.* > ELENCO 

invece di visualizzare l’elenco dei file che si trovano nella directory corrente, crea il file ‘ELENCO’ 

con questi dati. 

La ridirezione dello standard output fatta in questo modo, va a cancellare completamente il contenuto 

del file di destinazione, se questo esiste già; al contrario, si può utilizzare anche ‘>>’, con 

il quale, il file di destinazione viene creato se non esiste, oppure viene solo esteso. 

Lo standard input viene ridiretto utilizzando il simbolo ‘SORT < ELENCO > ORDINATO 

In questo modo, ‘SORT’ riceve dallo standard input il file ‘ELENCO’ e genera attraverso la 

ridirezione dello standard output il file ‘ORDINATO’.


Per mettere in contatto lo standard output di un comando con lo standard input del successivo, si 

utilizza il simbolo ‘|’. L’esempio seguente mostra un modo alternativo di ottenere l’ordinamento 

di un file: 

C:\>TYPE ELENCO | SORT > ORDINATO 

In generale, tutti i comandi che generano un risultato visuale che scorre sullo schermo, utilizzano 

semplicemente lo standard output, che può essere ridiretto in questo modo. Si osservi ancora 

l’esempio seguente che riordina il risultato del comando ‘DIR’, mostrandolo comunque sullo 

schermo: 

C:\>DIR *.DOC | SORT 

Nelle sezioni seguenti vengono mostrati alcuni comandi filtro. 

358.8.1 SORT 

SORT [opzioni] < file_da_ordinare > file_ordinato 

Il comando ‘SORT’, che dovrebbe corrispondere a un programma di servizio vero e proprio, riordina 

il file di testo che ottiene dallo standard input, generando un risultato che emette attraverso 

lo standard output. 



/R Riordina in modo decrescente 

Riordina in base al testo che inizia a partire dalla colonna in- 

/+n_colonna 

dicata come argomento (si tratta di un numero a partire da 

uno, per indicare la prima colonna). 

L’esempio seguente emette l’elenco della directory corrente riordinato in base all’estensione, che 

è un’informazione collocata a partire dalla decima colonna: 

C:\>DIR *.DOC | SORT /+10 

358.8.2 MORE 

MORE < file_da_leggere 

MORE file_da_leggere 

Il comando ‘MORE’ legge un file, fornito come argomento o attraverso lo standard input, mostrandolo 

poi sullo schermo una pagina dopo l’altra. In questo modo, è possibile leggere il contenuto 

dei file più lunghi delle righe a disposizione sullo schermo. 

Per passare alla pagina successiva, basta premere un tasto qualunque, oppure ciò che viene 

indicato espressamente. 


• C:\>DIR | MORE 

Permette di controllare lo scorrimento a video del risultato del comando ‘DIR’.


• C:\>MORE LETTERA.TXT 

Permette di controllare lo scorrimento a video del contenuto del file ‘LETTERA.TXT’. 

• C:\>TYPE LETTERA.TXT | MORE 

Si ottiene lo stesso risultato dell’esempio precedente, attraverso l’uso di una pipeline. 

358.9 Accesso diretto ai dispositivi 

Il Dos offre poche occasioni per accedere direttamente ai dispositivi. Si tratta generalmente solo 

della console e della porta parallela. L’esempio seguente mostra come «copiare» un file sul 

dispositivo di stampa, per ottenere così la sua stampa diretta: 

C:\>COPY LETTERA PRN: 

La stessa cosa avrebbe potuto essere ottenuta con la ridirezione dei flussi standard: 

C:\>TYPE LETTERA > PRN: 

Può essere interessante la possibilità di copiare il flusso di ingresso della console in un file: 

C:\>COPY CON: LETTERA 

In questo caso, l’inserimento nel file ‘LETTERA’ prosegue fino a quando viene ricevuto un codice 

EOF, che si ottiene qui con la combinazione di tasti [ Ctrl+z ] seguita da [ Invio ]. 

È bene ricordare che la console, ovvero il dispositivo ‘CON:’, riceve dati in ingresso attraverso la 

tastiera ed emette dati in uscita utilizzando lo schermo. In pratica, quando un programma attende 

dati dallo standard input non ridiretto, li riceve dalla console, cioè dalla tastiera; nello stesso 

modo, quando un programma emette dati attraverso lo standard output non ridiretto, li invia alla 

console, cioè sullo schermo. 

358.10 Riferimenti 

• FreeDOS 

 

• OpenDOS Unofficial Home Page 

 

Appunti di informatica libera 2003.06.29 --- Copyright © 2000-2003 Daniele Giacomini -- daniele @ swlibero.org

Dos: dischi, file system, directory e file 

Capitolo 359 

La gestione dei dischi, ovvero delle unità di memorizzazione di massa, è molto particolare nel 

Dos. In generale, si fa riferimento a queste cose attraverso un lettera che ne rappresenta il dispositivo; 

tuttavia, tale dispositivo può indicare un disco intero o solo una partizione, riferendosi 

sempre solo a dischi e partizioni Dos. 

359.1 Suddivisione in partizioni 

Nel Dos, tutti i dischi rimovibili, come i dischetti, non vanno suddivisi in partizioni, mentre i 

dischi fissi devono essere preparati in questo modo. Il programma che si usa per queste cose è 

‘FDISK’. 

Secondo il Dos, le partizioni di un disco possono essere solo quattro. Tuttavia, una partizione 

normale può essere suddivisa in sottopartizioni, che vengono definite tradizionalmente «estese», 

dove anche queste possono essere al massimo quattro. Una tale struttura ha condizionato 

in pratica anche altri sistemi operativi, per esempio GNU/Linux. Bisogna tenere in considerazione 

l’origine storica per comprendere che altri sistemi operativi possono comportarsi in 

modo completamente differente. 

Di solito, ‘FDISK’ ha una visione delle partizioni tutta orientata verso il Dos. Infatti, consente 

di creare una sola partizione primaria (ovvero una partizione normale) e altre partizioni estese 

(ovvero altre sottopartizioni di una seconda partizione primaria). 

Bisogna considerare che il settore di avvio del Dos viene collocato nel primo settore della partizione 

primaria utilizzata per il Dos. In questo modo, manca la sistemazione del primo settore del 

disco, l’MBR, che deve contenere il codice necessario a raggiungere il settore di avvio. 

FDISK [/MBR] 

In generale, sembra che le varie edizioni di ‘FDISK’ per Dos funzionino solo con il primo disco 

fisso. 

Fondamentalmente, il programma è interattivo, per cui si avvia una maschera con la quale si 

interviene per mezzo di un menù. Di norma viene consentito di cancellare le partizioni, di crearne 

una primaria e probabilmente una sola di estesa. 

Di solito, è possibile riscrivere il settore di avvio MBR attraverso l’opzione ‘/MBR’. 

359.2 Inizializzazione di un’unità di memorizzazione 

L’inizializzazione di un’unità di memorizzazione, intesa come un dischetto o una partizione, si 

ottiene con il comando ‘FORMAT’. Questo si occupa anche di predisporre il file system Dos-FAT 

ed eventualmente anche di trasferire il kernel, per renderlo avviabile. 

FORMAT lettera_unità: [/N:settori] [/T:cilindri] [/S] [/U] 

In alcune edizioni del Dos, questo comando non inizializza l’unità di memorizzazione, ma si 

limita a sovrascrivere la parte iniziale. Ciò viene fatto per accelerare il procedimento e per 

permettere eventualmente il recupero dei dati, in caso di ripensamenti. In generale, sarebbe 

meglio evitare questa scorciatoia quando si tratta di unità corrispondenti ai dischetti; così, per 

confermare la richiesta di un’inizializzazione tradizionale, si può aggiungere l’opzione ‘/U’. 

100

Dos: dischi, file system, directory e file 101 


• C:\>FORMAT A: /U 

Inizializza l’unità ‘A:’, corrispondente a un dischetto. L’inizializzazione avviene in modo 

completo, essendo stata usata l’opzione ‘/U’; inoltre, dal momento che non sono state 

indicate altre cose, il formato usato è quello predefinito in base alla configurazione del 

firmware. 

• C:\>FORMAT A: /N:9 /T:40 /U 

Come nell’esempio precedente, con l’aggiunta dell’indicazione della geometria: nove settori 

per traccia e 40 cilindri; si sottintende la presenza di due tracce per cilindro. Pertanto, 

dal momento che ogni settore è di 512 byte: 2 * 40 * 9 * 512 byte = 360 Kibyte. 

• C:\>FORMAT A: /N:9 /T:80 /U 

Come nell’esempio precedente, ma con 80 cilindri: 2 * 80 * 9 * 512 byte = 720 Kibyte. 

• C:\>FORMAT A: /N:15 /T:80 /U 

Come nell’esempio precedente, ma con 15 settori per traccia: 2 * 80 * 15 * 512 byte = 

1200 Kibyte. 

• C:\>FORMAT A: /N:18 /T:80 /U 

Come nell’esempio precedente, ma con 18 settori per traccia: 2 * 80 * 18 * 512 byte = 

1440 Kibyte. 

• C:\>FORMAT A: /S 

Inizializza il dischetto corrispondente all’unità ‘A:’, trasferendo successivamente il kernel 

e probabilmente anche l’interprete dei comandi (‘COMMAND.COM’). Ciò avviene perché è 

stata usata l’opzione ‘/S’. 

359.3 Etichetta di un’unità di memorizzazione 

Tradizionalmente, il Dos prevede la possibilità di attribuire un nome a un’unità di memorizzazione. 

Questo nome viene definito solitamente «etichetta» e di fatto viene annotato come un file 

speciale nella directory radice (anche se poi non appare nell’elenco). Per modificare o attribuire 

questo nome si utilizza il comando ‘LABEL’: 

LABEL [lettera_unità:][nome] 

Se non si indica la lettera dell’unità di memorizzazione su cui intervenire, si tratta implicitamente 

di quella da cui è stato avviato il sistema; se non si indica il nome da attribuire, ‘LABEL’ funziona 

in modo interattivo, chiedendo il da farsi. 

In linea di principio, l’etichetta di un’unità non serve, salvo il caso di qualche programma che 

potrebbe utilizzarla per uno scopo particolare (per esempio i programmi di installazione per 

identificare i dischetti).


Esiste anche un altro comando interno per la verifica del nome di un’unità; si tratta di ‘VOL’: 

VOL [lettera_unità:] 

Il risultato è solo l’informazione del nome stesso, con l’aggiunta del numero di serie se questo 

dato è disponibile. 

359.4 Analisi e correzione del file system 

Esistono pochi strumenti di analisi e correzione degli errori nel file system. In origine si tratta del 

comando ‘CHKDSK’, a cui in seguito si è aggiunto ‘SCANDISK’. 

CHKDSK lettera_unità: [/F] 

‘CHKDSK’ può essere usato solo con l’indicazione di un’unità di memorizzazione; in tal caso 

restituisce le informazioni disponibili su questa. Se si aggiunge l’opzione ‘/F’, si richiede 

esplicitamente la correzione, per quanto possibile, degli errori rilevati. 

L’errore tipico di un file system Dos-FAT si traduce in «concatenamenti perduti», ovvero file, 

interi o parziali, di cui non si può conoscere il nome. Questi file potrebbero essere solo dati 

temporanei che è bene siano cancellati, ma questa non è la regola. ‘CHKDSK’ tende a salvare 

questi file assegnando loro un nome più o meno casuale, lasciando all’utilizzatore l’onere di 

decidere cosa farne. 

359.5 Copia 

Nei sistemi Dos la copia è un’attività piuttosto articolata. In pratica, il comando interno ‘COPY’ 

consente solo di copiare file puri e semplici. Per copiare un dischetto occorre il comando 

‘DISKCOPY’; per copiare file e directory occorre il comando ‘XCOPY’. 

359.5.1 DISKCOPY 

DISKCOPY unità_di_origine: unità_di_destinazione: 

‘DISKCOPY’ permette di eseguire la copia di un’unità di memorizzazione, purché si tratti di un 

dischetto. Il dischetto di destinazione dovrebbe essere inizializzato preventivamente. 

L’unità indicata come secondo argomento, che rappresenta la destinazione, può essere la stessa 

di quella di origine. In questo caso, i dischetti andranno alternati nel dispositivo che li ospita, 

seguendo le istruzioni che dà ‘DISKCOPY’ stesso. 

L’esempio seguente esegue la copia di un dischetto usando lo stesso dispositivo fisico: 

C:\>DISKCOPY A: A: 

359.5.2 XCOPY 

XCOPY percorso_origine [percorso_destinazione] [/E] [/S] [/H] [/V] 

‘XCOPY’ consente di copiare uno o più file assieme alla struttura di directory. In altri termini, ciò 

significa che è possibile copiare anche una directory intera.




/S Copia solo le directory e le sottodirectory non vuote. 

/E Copia tutte le sottodirectory, anche se vuote. 

/H Copia anche i file nascosti e di sistema. 

/V Verifica la copia. 

L’esempio seguente copia tutta la struttura che si articola a partire dalla directory ‘\PIPPO\’, 

nella directory ‘\PAPPA\’, includendo anche i file nascosti e quelli di sistema: 

C:\>XCOPY \PIPPO\*.* \PAPPA\*.* /E /S /H /V 

359.6 Trasferimento del sistema 

Il Dos è un sistema operativo elementare. L’essenziale in assoluto è costituito dal kernel e dall’interprete 

dei comandi. Per rendere «avviabile» un dischetto o una partizione basta copiare questi 

file e sistemare il settore di avvio, in modo che punti correttamente al kernel. Questo si può ottenere 

con il comando ‘FORMAT’, quando lo si usa con l’opzione ‘/S’ (cosa che naturalmente 

implica anche l’inizializzazione dell’unità), oppure con il comando ‘SYS’, fatto appositamente 

per questo: 

FORMAT lettera_unità: /S 

SYS lettera_unità: 

A seconda del tipo di Dos, vengono copiati solo i file del kernel, oppure anche l’interprete dei 

comandi (necessario per avviare il sistema). 

359.7 Modifica delle unità 

La caratteristica del Dos per cui si distinguono le unità di memorizzazione, introduce l’esigenza 

di comandi particolari, che vengono descritti brevemente nelle sezioni seguenti. In particolare, 

si tratta della possibilità di attribuire una lettera di unità differente e di poter inserire un’unità in 

una directory come avviene con l’innesto di un file system nei sistemi Unix. 

359.7.1 ASSIGN 

ASSIGN lettera_unità_1[:]=lettera_unità_2[:] 

ASSIGN /STATUS 

ASSIGN 

Il comando ‘ASSIGN’ permette di modifica il nome di un’unità di memorizzazione. Per ottenere 

questo risultato, rimane attivo come programma residente in memoria. Quando si usa senza 

argomenti, ‘ASSIGN’ elimina tutte le ridefinizioni; con l’opzione ‘/STATUS’ si ottiene lo stato 

attuale delle ridefinizioni; quando si indicano le lettere di unità, la prima è l’unità virtuale che 

viene creata come riproduzione della seconda. 


• C:\>ASSIGN E:=A: 

Dopo questo comando, per accedere all’unità corrispondente al primo dischetto, si potrà 

indicare l’unità ‘E:’.


• C:\>ASSIGN 

Cancella tutte le ridefinizioni delle unità di memorizzazione. 

359.7.2 JOIN 

JOIN lettera_unità: percorso 

JOIN lettera_unità: /D 

JOIN 

Il comando ‘JOIN’ permette di attaccare un’unità di memorizzazione in corrispondenza di un 

percorso (una directory). Si tratta in pratica di montare l’unità, come avviene nei sistemi Unix. 

Quando si usa ‘JOIN’ senza argomenti, si ottiene un elenco degli innesti attivi; quando si usa 

l’opzione ‘/D’, si vuole annullare il collegamento dell’unità. 


• C:\>JOIN A: C:\MNT\A 

Innesta l’unità ‘A:’ nella directory ‘C:\MNT\A\’. 

• C:\>JOIN A: /D 

Distacca l’unità ‘A:’ da un collegamento precedente. 

359.7.3 SUBST 

SUBST lettera_unità: percorso 

SUBST /D 

Il comando ‘SUBST’ permette di creare un’unità virtuale a partire da una directory di un’altra 

unità. In pratica, si fa in modo di permettere l’identificazione di una certa directory attraverso 

l’uso di una lettera di unità. 

Quando si usa ‘JOIN’ con l’opzione ‘/D’, si vuole annullare l’unità virtuale relativa. 


• C:\>SUBST E: C:\EXTRA\E 

Crea l’unità virtuale ‘E:’ a partire dal contenuto delle directory ‘C:\EXTRA\E\’. 

• C:\>JOIN E: /D 

Elimina l’unità virtuale ‘E:’.


359.8 Altre particolarità 

La gestione del Dos di file e directory è molto strana. Nelle sezioni seguenti vengono descritti 

alcuni programmi tipici dei sistemi Dos riguardanti la gestione di file e directory, che non hanno 

trovato un’altra collocazione in questo documento, a causa della loro particolarità. 

359.8.1 VERIFY 

VERIFY [ON|OFF] 

Il comando interno ‘VERIFY’ permette di richiedere al sistema operativo di verificare la registrazione 

nelle unità di memorizzazione. Come si vede dallo schema sintattico, si attiva o si disattiva 

la modalità, attraverso l’uso delle parole chiave ‘ON’ oppure ‘OFF’. Di solito, questa modalità è 

disabilitata ed è difficile definire la reale importanza di questa impostazione. 

Se si usa il comando senza alcun argomento, si ottiene di sapere quale sia l’impostazione attuale. 

359.8.2 APPEND 

APPEND directory 

APPEND ; 

APPEND 

Il comando ‘APPEND’ consente di definire un percorso per la ricerca dei file di dati. In pratica, 

si vuole permettere ai programmi di accedere a file di dati anche quando questi si trovano fuori 

della collocazione prevista. ‘APPEND’ può essere usato più volte, per aggiungere altre directory. 

Se viene usato con l’argomento ‘;’, si intende cancellare tutto l’elenco di directory di ricerca dei 

file di dati. Se viene usato senza argomenti, si ottiene l’elenco di queste directory. 

L’esempio seguente aggiunge la directory ‘C:\DATI\’ all’elenco dei percorsi di ricerca per i file 

di dati: 

C:\>APPEND C:\DATI 

359.8.3 ATTRIB 

ATTRIB [+R|-R] [+A|-A] [+S|-S] [+H|-H] file 

Il comando ‘ATTRIB’ permette di visualizzare o cambiare gli attributi del file. In pratica, 

utilizzando la forma ‘+x’ si attiva l’attributo x, mentre con ‘-x’ si disattiva l’attributo stesso. 


• C:\>ATTRIB *.* 

Mostra gli attributi di tutti i file contenuti nella directory corrente. 

• C:\>ATTRIB +R *.* 

Imposta l’attributo di sola lettura per tutti i file della directory corrente.


359.8.4 DELTREE 

DELTREE directory 

Il comando ‘DELTREE’ consente di eliminare una directory con tutto il suo contenuto, 

ricorsivamente. 

L’esempio seguente elimina la directory ‘C:\TEMP\CIAO\’ assieme a tutto il suo contenuto: 

C:\>DELTREE C:\TEMP\CIAO 

359.8.5 FIND 

FIND [opzioni] "stringa" [file] 

Il comando ‘FIND’ è uno dei più complessi nei sistemi Dos. Serve per fare una ricerca di una 

stringa in uno o più file, in base a quanto indicato nell’ultimo argomento, oppure all’interno 

dello standard input. Il risultato normale della ricerca è l’emissione delle righe che contengono 

la stringa cercata, assieme all’indicazione del file a cui appartengono. 



/V 

La ricerca avviene per le righe che non contengono la stringa 

cercata. 

/C 

Mostra solo il totale delle righe che contengono la stringa 

cercata. 

/N Mostra il numero di ogni riga che contiene la stringa cercata. 

Ignora la differenza tra maiuscole e minuscole per il confronto 

/I 

con la stringa di ricerca. 

In alcune edizioni del Dos, questa modalità di funzionamento 

è predefinita. 

Segue al descrizione di alcuni esempi. 

• C:\>FIND "ciao" *.* 

Cerca la stringa ‘ciao’ in tutti i file della directory corrente. 

• C:\>FIND "ciao" < MIO.TXT 

Cerca la stringa ‘ciao’ nel file ‘MIO.TXT’ che viene fornito attraverso lo standard input. 

359.8.6 MOVE 

MOVE file_origine directory_destinazione 

MOVE directory_origine directory_destinazione 

Il comando ‘MOVE’ consente di spostare file o directory in altre collocazioni. In generale, ‘MOVE’ 

si occupa di spostare e non di rinominare i file, che invece è una funzione del comando ‘REN’. 

Il comando ‘MOVE’ è ambiguo e si comporta in maniera differente da una realizzazione all’altra 

dei sistemi Dos. In generale bisogna considerare che la destinazione può esistere o meno, 

implicando dei comportamenti differenti da valutare.


L’esempio seguente sposta i file e le directory contenute in ‘C:\CIAO\’ nella directory ‘C:\ 

MIA\’. Se la directory di destinazione non c’è, questa dovrebbe essere creata automaticamente, 

ma la cosa va verificata: 

C:\>MOVE C:\CIAO\*.* C:\MIA 

359.8.7 TREE 

TREE [directory] 

Il comando ‘TREE’ consente di visualizzare la struttura della directory corrente, oppure di un’altra 

directory indicata come argomento. 

L’esempio seguente mostra la struttura della directory ‘C:\CIAO\’: 

C:\>TREE C:\CIAO 

359.8.8 COMP e FC 

COMP file_1 file_2 [opzioni] 

FC file_1 file_2 [opzioni] 

I comandi ‘COMP’ e ‘FC’ permettono di verificare se due file sono identici, oppure no. Non sono 

molto facili da utilizzare, specialmente il primo; probabilmente vale la pena di sapere che ci sono, 

senza poi pretendere di sfruttare tutte le loro possibilità. 

‘FC’ assomiglia molto vagamente a un comando ‘diff’ di Unix, dal momento che di fronte a file 

di testo cerca di comprendere quale cambiamento è stato fatto. In questo senso, è probabile che 

‘FC’ sia il più utile tra questi due. 


Dos: configurazione 

Capitolo 360 

Nel Dos è un po’ difficile scindere i concetti di configurazione e script, perché per configurare il 

sistema, occorre predisporre degli script. Si tratta dei file ‘\CONFIG.SYS’ e ‘\AUTOEXEC.BAT’, 

collocati nell’unità di avvio. Questo fatto è già stato accennato nel capitolo introduttivo; in questo 

si vuole approfondire un po’ la cosa. 

360.1 CONFIG.SYS 

Il file ‘CONFIG.SYS’, collocato nella directory radice dell’unità di avvio, è uno script speciale 

avviato dal kernel prima dell’interprete dei comandi. In linea di massima, si tratta di una sequenza 

di direttive che occupano ognuna una riga; alcune versioni recenti del Dos consentono di 

suddividere le direttive in sezioni da scegliere in base a un menù iniziale. 

Le direttive di ‘CONFIG.SYS’ hanno la forma seguente: 

nome=valore 

In pratica, si assegna una stringa (senza delimitatori espliciti) a un nome che ha un significato 

particolare. 

In questo file, vengono ignorate le righe vuote, quelle bianche e quelle che iniziano con la parola 

chiave ‘REM’: 

REM annotazione 

È importante osservare che i nomi delle direttive non fanno differenza tra lettere maiuscole 

e minuscole. In generale, questo vale anche per le stringhe che vengono assegnate a questi 

nomi. 

360.1.1 BREAK 

BREAK={ON|OFF} 

Teoricamente, questa istruzione consente di attivare o di disattivare la funzionalità abbinata alla 

combinazione di tasti [ Ctrl+c ]. In condizioni normali, quando si assegna la parola chiave ‘ON’, si 

attiva il funzionamento della combinazione [ Ctrl+c ]. 

360.1.2 BUFFERS 

BUFFERS=n_buffer[,n_buffer_secondari] 

Questa istruzione consente di definire la quantità di memoria tampone per gli accessi ai dischi. 

Si assegnano uno o due valori numerici, separati da una virgola. Il primo valore va da 1 a 99 ed 

esprime il numero di aree da usare come memoria tampone; il secondo valore, facoltativo, indica 

delle memorie tampone secondarie, con valori che vanno da uno a otto. 

108

Dos: configurazione 109 

360.1.3 COUNTRY 

COUNTRY=n_codice_paese[,[n_codifica][,file_informazioni_nazionali]] 

Questa istruzione, attraverso quanto contenuto in un file che tradizionalmente si chiama 

‘COUNTRY.SYS’, permette di configurare il sistema in base alla nazionalità. Per la precisione, 

si può specificare un codice riferito alla nazionalità, attraverso il quale si ottiene una forma particolare 

per le date e gli orari, con l’aggiunta eventuale di un altro codice che specifica la codifica 

dei caratteri prescelta (codepage). La tabella 360.1 riepiloga questi codici che fanno riferimento 

tradizionalmente anche a paesi che non esistono più. 

Si può osservare che la stringa assegnata alla direttiva ‘COUNTRY’ può contenere l’indicazione 

di un file (con il percorso, completo di unità o meno). Questo file è quello che contiene poi 

le indicazioni relative alla nazionalità prescelta; come già accennato, di solito si tratta del file 

‘COUNTRY.SYS’. 

Tabella 360.1. Codici di nazionalità. 

Località Codice di nazionalità Codifiche utili 

USA 001 437, 850 

Canada francese 002 863, 850 

America latina 003 850, 437 

Russia 007 866, 437 

Olanda 031 850, 437 

Belgio 032 850, 437 

Francia 033 850, 437 

Spagna 034 850, 437 

Ungheria 036 850, 852 

Jugoslavia 038 850, 852 

Italia 039 850, 437 

Svizzera 041 850, 437 

Cecoslovacchia 042 850, 852 

Regno unito 044 850, 437 

Danimarca 045 850, 865 

Svezia 046 850, 437 

Norvegia 047 850, 865 

Polonia 048 850, 852 

Germania 049 850, 437 

Brasile 055 850, 860 

Australia 061 850, 437 

Giappone 081 932, 437, 850, 942 

Corea 082 934, 437, 850, 944 

Cina 088 938, 437, 850, 948 

Turchia 090 857, 850 

Asia (inglese) 099 850, 437 

Portogallo 351 850, 860 

Islanda 354 850, 861 

Finlandia 358 850, 437 

L’esempio seguente predispone l’impostazione nazionale per l’Italia, utilizzando la codifica 850, 

che ha il vantaggio di essere quella più comune dei paesi che usano l’alfabeto latino: 

COUNTRY=039,850,C:\DOS\COUNTRY.SYS


360.1.4 DEVICE, DEVICEHIGH 

DEVICE=programma_di_gestione_dispositivo [opzioni] 

DEVICEHIGH=programma_di_gestione_dispositivo [opzioni] 

Si tratta di un modo per avviare un programma speciale che ha lo scopo di rimanere residente 

in memoria. In generale, tali programmi servono per la gestione di qualche dispositivo, 

indispensabile prima di avviare l’interprete dei comandi. 

La differenza tra le due direttive sta nel fatto che la seconda cerca di caricare il programma nella 

memoria «alta». 

Le opzioni riguardano il programma. 

L’esempio seguente avvia il programma ‘MOUSE.SYS’ che presumibilmente gestisce il mouse 

(l’opzione ‘/2’ serve probabilmente a utilizzare il mouse collegato alla seconda porta seriale): 

DEVICE=C:\MOUSE\MOUSE.SYS /2 

360.1.5 DOS 

DOS={HIGH|LOW}[,{UMB|NOUMB}] 

DOS=[{HIGH|LOW},]{UMB|NOUMB} 

Questa istruzione richiede al kernel di allocarsi nella memoria convenzionale, ‘LOW’, o in quella 

alta, ‘HIGH’. La parola chiave ‘UMB’ richiede di mantenere un collegamento tra la UMB e la 

memoria convenzionale; la parola chiave ‘NOUMB’ fa sì che questo collegamento non abbia luogo. 

360.1.6 DRIVEPARM 

DRIVEPARM=[opzioni] 

Si tratta di una direttiva attraverso cui si possono definire i parametri relativi ai dispositivi a 

blocchi, per la precisione si tratta solo di dischi, se questo può essere necessario. Le opzioni 

assomigliano a quelle dei programmi di servizio, iniziando con una barra obliqua normale: ‘/x...’. 



/d:n_dispositivo_fisico 

Consente di indicare il dispositivo attraverso un numero, da 0 

a 255. Lo zero corrisponde alla prima unità a dischetti. 

/c 

Se si utilizza questa opzione, si intende che l’unità fisica è in 

grado di sapere se il disco è inserito o meno. 

/f:n_formato 

Stabilisce il formato del dispositivo fisico; in pratica, fissa la 

geometria. 

/f:0 Dischetto 160 Kibyte, 180 Kibyte, 320 Kibyte, 360 Kibyte. 

/f:1 Dischetto 1200 Kibyte. 


/f:5 Disco fisso. 

/f:6 Nastro. 



/h:n_testine Definisce il numero di testine. 

/i Indica che si tratta di un dischetto da 3,5 pollici.



/n Si tratta di un disco fisso. 

/s:n_settori Definisce il numero di settori per traccia. 

/t:n_cilindri 

Definisce il numero dei cilindri (in altri termini: il numero di 

tracce per faccia). 

360.1.7 FCBS 

FCBS=n_blocchi 

Permette di definire il numero di blocchi di controllo dei file (file control block). Il valore va da 1 

a 255, mentre il valore normale è di quattro blocchi. 

360.1.8 FILES 

FILES=n_blocchi 

Permette di indicare il numero massimo di file aperti. Il numero che può essere assegnato va da 

8 a 255. Il valore predefinito dovrebbe essere di otto file. 

360.1.9 INSTALL 

INSTALL=programma [opzioni] 

Si tratta di un’istruzione con la quale si può avviare preventivamente un programma (che dovrebbe 

essere residente in memoria), prima dell’avvio dell’interprete dei comandi. In questo caso, a 

differenza della direttiva ‘DEVICE’, o ‘DEVICEHIGH’, si tratta di un programma normale. 

Le opzioni riguardano il programma. 

360.1.10 LASTDRIVE 

LASTDRIVE=lettera_unità_finale 

Consente di specificare l’ultima lettera di unità che può essere richiesta. Questo consente di 

risparmiare risorse, se si è consapevoli del fatto che non servono lettere oltre un certo punto. La 

lettera in questione può essere indifferentemente maiuscola o minuscola, senza che ciò possa fare 

differenza. 

360.1.11 SHELL 

SHELL=programma [opzioni] 

Permette di indicare esplicitamente il programma da avviare alla fine della procedura di avvio 

del kernel. In generale si tratta dell’interprete dei comandi. Questa direttiva può consentire di avviare 

un interprete alternativo a quello normale, oppure permette di avviarlo da una collocazione 

insolita; inoltre permette di dare al programma in questione delle opzioni particolari. 

L’esempio seguente avvia il programma ‘COMMAND.COM’ che si trova nella directory ‘C:\DOS\’: 

SHELL=C:\DOS\COMMAND.COM


360.1.12 STACK 

STACK=n_livelli[,dimensione_in_byte] 

Con questa istruzione è possibile fissare la dimensione dello stack, utilizzando valori da 8 a 64, 

oltre allo zero. Il valore dopo la virgola indica la dimensione in byte di ogni livello dello stack. 

In questo caso i valori vanno da 32 a 512. 

360.2 AUTOEXEC.BAT 

Il file ‘AUTOEXEC.BAT’ collocato nella directory radice dell’unità di avvio, è inteso essere uno 

script che viene eseguito dall’interprete dei comandi, ‘COMMAND.COM’, dopo l’avvio del sistema. 

Questo script viene realizzato normalmente in modo sequenziale, senza strutture di controllo. 

In generale è importante per due cose: impostare alcune variabili di ambiente fondamentali, per 

esempio ‘PATH’; avviare dei programmi che poi restano residenti in memoria, quando questo non 

si ottiene già attraverso il file ‘\CONFIG.SYS’. 

360.3 Comandi ridondanti 

Anche nel Dos è molto importante l’uso delle variabili di ambiente. È già stato mostrato il 

comando ‘SET’, attraverso il quale si impostano o si annullano le variabili di ambiente: 

SET nome_variabile=stringa_assegnata 

Alcune variabili hanno un’importanza particolare, per cui esiste un comando interno apposito 

(dell’interprete dei comandi), che serve a inizializzarle senza nemmeno l’uso del comando ‘SET’. 

• PROMPT stringa_di_invito 

Il comando interno ‘PROMPT’ rappresenta un modo alternativo per impostare la variabile di 

ambiente con lo stesso nome. Se si usa il comando senza l’argomento, si ripristina l’invito 

predefinito. 

• PATH [percorsi_degli_eseguibili] 

Il comando interno ‘PATH’ rappresenta un modo alternativo per impostare la variabile di 

ambiente con lo stesso nome. Se non si indica l’argomento, si ottiene la visualizzazione 

dell’elenco dei percorsi attivo. 

Esistono altri comandi particolari che si sovrappongono alle istruzioni del file ‘CONFIG.SYS’. 

• BREAK [ON|OFF] 

Abilita o disabilita la funzionalità abbinata alla combinazione di tasti [ Ctrl+c ]. Utilizzando 

il comando senza argomento, si ottiene la visualizzazione dello stato attuale.


360.4 Localizzazione 

La localizzazione del Dos si riduce alla configurazione della mappa della tastiera e alla definizione 

dell’insieme di caratteri. L’insieme di caratteri dipende dalla scelta della nazionalità, fatta 

nel file ‘CONFIG.SYS’, attraverso la direttiva ‘COUNTRY’. 

Nelle sezioni seguenti vengono mostrati alcuni comandi utili per le impostazioni che riguardano 

la localizzazione. 

360.4.1 CHCP 

CHCP [n_codifica] 

Si tratta di un comando interno dell’interprete dei comandi che interviene nella definizione della 

codifica utilizzata. In pratica, se si utilizza senza argomenti, mostra il numero della codifica attiva; 

se si indica un numero come argomento, cambia la codifica attiva, purché questa sia una di quelle 

ammissibili in base alla nazionalità stabilita con la direttiva ‘COUNTRY’ nel file di configurazione 

‘CONFIG.SYS’. 

L’esempio seguente fa in modo che sia attivata la codifica corrispondente al numero 850: 

C:\>CHCP 850 

360.4.2 KEYB 

KEYB [sigla_nazionale[,[n_codifica][,file_informazioni_tastiere]]] 

‘KEYB’ è un comando esterno che consente di cambiare la configurazione della tastiera secondo 

alcuni modelli di nazionalità predefiniti. La sigla nazionale è un codice di due lettere che, assieme 

alla nazionalità, dovrebbe indicare anche la lingua utilizzata. La tabella 360.3 elenca queste sigle. 

Tabella 360.3. Sigle nazionali-linguistiche per l’impostazione della mappa della 

tastiera. 


Sigla Corrispondenza 

US USA (predefinito) 

FR Francia 

GR Germania 

IT Italia 

SP Spagna 

UK Gran Bretagna 

PO Portogallo 

SG Svizzera tedesca 

SF Svizzera francese 

DK Danimarca 

BE Belgio 

NL Olanda (Nederland) 

NO Norvegia 

LA America latina 

SV Svezia 

SU Finlandia (Suomi) 

CF Canada francese


• C:\>KEYB 

Mostra la configurazione attuale. 

• C:\>KEYB IT 

Predispone la mappa dei tasti per la disposizione italiana. 

• C:\>KEYB IT,850,C:\DOS\KEYBOARD.SYS 

Predispone la mappa dei tasti per la disposizione italiana, specificando l’uso della codifica 

850 e del file ‘C:\DOS\KEYBOARD.SYS’ per trovare le impostazioni standard delle tastiere. 

360.4.3 GRAFTABL 

GRAFTABL [n_codifica] 

GRAFTABL /STATUS 

‘GRAFTABL’ è un comando esterno che consente di cambiare la codifica per i caratteri visualizzati 

sullo schermo. L’opzione ‘/STATUS’ permette di conoscere la situazione attuale, mentre 

l’indicazione di un numero di codifica cambia l’impostazione. 

L’esempio seguente imposta l’uso della codifica 850: 

C:\>GRAFTABL 850 

360.5 Orologio 

Il Dos consente di accedere all’orologio dell’elaboratore, per leggere la data e l’ora, o per cambiare 

tali informazioni. In generale, il Dos non prevede la gestione di un orologio hardware allineato 

al tempo universale; pertanto, l’orologio hardware deve corrispondere necessariamente all’ora 

locale, lasciando all’utente il problema legato alle variazioni dell’ora estiva. 

I comandi per accedere all’orologio sono ‘DATE’ e ‘TIME’: 

DATE [data] 

TIME [orario] 

Se non si indica la data o l’orario, viene mostrato quello attuale e viene richiesto all’utente di 

modificarlo o di confermarlo. 

Il modo in cui va scritta da data o l’ora, dipende dalla localizzazione. Per conoscere quello giusto, 

basta osservare in che modo vengono visualizzate tali informazioni. 


Dos: script dell’interprete dei comandi 

Capitolo 361 

Uno script dell’interprete dei comandi, conosciuto solitamente con il nome di file batch, potrebbe 

essere definito come un file di testo normale in cui può essere indicato un elenco di comandi da 

eseguire. Tuttavia, questi script consentono l’uso anche di strutture di controllo elementari, per 

cui si possono realizzare dei programmi molto semplici, senza troppe pretese. 

È interessante osservare che questi script vengono individuati solo attraverso l’estensione che ha 

il nome: ‘.BAT’. Inoltre, non esiste la necessità di renderli «eseguibili» come si fa nei sistemi 

Unix. 

361.1 Parametri, variabili ed espansione 

Gli script dell’interprete dei comandi hanno accesso agli argomenti che vengono loro forniti. Si 

possono gestire solo nove di questi argomenti alla volta, attraverso i parametri posizionali relativi, 

da ‘%1’ a ‘%9’. Come avviene nelle shell Unix, è disponibile il comando interno ‘SHIFT’ per fare 

scorrere in avanti gli argomenti nei parametri disponibili. 

Bisogna ricordare che in Dos i caratteri jolly non vengono espansi dalla shell, per cui la 

limitazione a soli nove parametri posizionali, non dovrebbe costituire un problema. 

Nell’ambito di uno script possono essere dichiarate e utilizzate delle variabili di ambiente. È già 

stato mostrato in precedenza l’uso del comando ‘SET’ per impostare o eliminare le variabili di 

ambiente. Per fare riferimento al contenuto di una variabile, si usa la notazione seguente: 

%nome_variabile% 

L’esempio seguente rappresenta il caso tipico di estensione di un percorso di ricerca degli 

eseguibili, quando si ritiene che la variabile ‘PATH’ sia già stata usata: 

SET PATH=%PATH%;C:\PIPPO 

361.2 Chiamate di altri script 

Tradizionalmente, il Dos ha un baco molto grave, ormai divenuto una caratteristica fondamentale, 

riguardante l’avvio di script all’interno di altri script. In generale, quando si chiama un 

programma che in realtà corrisponde a uno script, al termine di questo non riprende l’esecuzione 

di quello chiamante. Per ottenere la ripresa dell’interpretazione dello script di partenza occorre 

usare il comando speciale ‘CALL’. 

CALL nome_script [argomenti_dello_script] 

361.3 Strutture di controllo 

Le strutture di controllo per la programmazione attraverso gli script dell’interprete dei comandi 

sono molto limitate. È disponibile una struttura condizionale semplificata e un ciclo di scansione 

di file, che vengono descritti brevemente. 

115


361.3.1 IF 

IF [NOT] ERRORLEVEL valore_di_uscita_ultimo_comando comando 

IF [NOT] stringa_1==stringa_2 comando 

IF [NOT] EXIST file comando 

La struttura condizionale degli script dell’interprete dei comandi Dos è in pratica un comando 

interno dello stesso interprete. Come si può vedere dagli schemi sintattici, viene fornita una 

condizione che può essere invertita con la parola chiave ‘NOT’ e il risultato è solo l’esecuzione di 

un altro comando se la condizione risulta vera. 

Nel primo caso, la condizione si riferisce alla verifica del valore di uscita dell’ultimo comando 

eseguito. La condizione si verifica se il numero indicato è inferiore o uguale al valore restituito 

effettivamente da tale comando; nel secondo, la condizione si verifica se le due stringhe 

(non delimitate) sono identiche; nel terzo si verifica la condizione se il file indicato esiste 

effettivamente. 


• IF ERRORLEVEL 1 GOTO :errore 

Se il comando precedente ha restituito un valore maggiore o uguale a uno, salta all’etichetta 

‘:errore’. 

• IF %1==ciao ECHO L’argomento è corretto 

In questo caso, se l’espansione del parametro ‘%1’, corrispondente al primo argomento 

ricevuto all’avvio, si traduce nella stringa ‘ciao’, viene emesso un messaggio per mezzo 

del comando ‘ECHO’. 

• IF %1x==x ECHO L’argomento è mancante 

Quello che si vede è il trucco necessario per poter verificare se un parametro contiene 

la stringa nulla: si aggiunge una lettera, in questo caso una «x», verificando che la 

corrispondenza avvenga solo con la stessa lettera. 

• IF NOT EXIST LETTERA.TXT ECHO Scrivi! > LETTERA.TXT 

Qui, se non esiste il file ‘LETTERA.TXT’ nella directory corrente, questo file viene creato 

attraverso il comando ‘ECHO’ che invia il suo standard output verso un file con lo stesso 

nome. 

361.3.2 FOR 

FOR [%]%x IN (nome...) DO comando [argomenti_del_comando] 

Si tratta di un comando interno che svolge un ciclo di scansione di un gruppo di nomi, generalmente 

file, attraverso il quale viene creato un parametro variabile speciale, il cui nome si compone 

di una sola lettera, a cui viene assegnato a ogni ciclo uno dei nomi contenuti tra parentesi tonde. 

A ogni ciclo viene eseguito il comando, che a sua volta può fare uso del parametro. 1 

1 Questo parametro assomiglia a una variabile di ambiente, ma non si comporta allo stesso modo. Si tratta di una 

particolarità del comando ‘FOR’.

Dos: script dell’interprete dei comandi 117 

Quando viene usato all’interno di uno script dell’interprete dei comandi, il parametro viene 

indicato con due simboli di percentuale (‘%%x’); al contrario, se il comando viene impartito 

dalla riga di comando, se ne usa uno solo. 


• FOR %A IN (uno due tre) DO ECHO %A 

• 

In questo modo, si ottiene la visualizzazione delle parole ‘uno’, ‘due’ e ‘tre’. In pratica, è 

come se fosse stato fatto: 

ECHO uno 

ECHO due 

ECHO tre 

Volendo fare la stessa cosa dalla riga di comando, è necessario il raddoppio del simbolo ‘%’: 

C:\>FOR %%A IN (uno due tre) DO ECHO %%A 

• FOR %A IN (*.TMP *.BAD) DO DEL %A 

Cancella, uno a uno, tutti i file che terminano con le estensioni ‘.TMP’ e ‘.BAD’. 

361.3.3 GOTO 

GOTO etichetta 

Gli script dell’interprete dei comandi dispongono dell’istruzione di salto incondizionato, non 

avendo di meglio. Anche questa istruzione può essere presa come un comando interno 

dell’interprete, con la differenza che non c’è modo di utilizzarlo al di fuori di uno script. 

Nel corso di uno script del genere, possono apparire delle righe che contengono solo un’etichetta, 

nella forma: 

:nome_etichetta 

La posizione corrispondente a queste etichette può essere raggiunta con il comando ‘GOTO’, che 

può fare riferimento solo al nome dell’etichetta, oppure a tutta l’etichetta, includendo anche i due 

punti. 


• 

• 

IF EXIST LETTERA.TXT GOTO riprendi 

ECHO Il file LETTERA.TXT è assente 

:riprendi 

In questo esempio, se il file ‘LETTERA.TXT’ esiste, si salta all’etichetta ‘:riprendi’; 

altrimenti si esegue il comando ‘ECHO’. 

IF EXIST LETTERA.TXT GOTO :riprendi 

ECHO Il file LETTERA.TXT è assente 

:riprendi 

Esattamente come nell’esempio precedente, con la differenza che il comando ‘GOTO’ indica 

l’etichetta con i suoi due punti iniziali.


361.3.4 Emulazione di un ciclo iterativo 

Dal momento che non è disponibile una struttura di controllo per il ciclo iterativo, questo può 

essere ottenuto solo attraverso l’uso del comando ‘GOTO’. Vale la pena di mostrare in che modo 

si può ottenere tale risultato. 

:etichetta_di_ingresso 

IF condizione GOTO :etichetta_di_uscita 

... 

... 

... 

GOTO etichetta_di_ingresso 

:etichetta_di_uscita 

:etichetta_di_ingresso 

... 

... 

... 

IF condizione GOTO :etichetta_di_ingresso 

:etichetta_di_uscita 

I due modelli sintattici mostrano due esempi di cicli iterativi. Nel primo caso si verifica una 

condizione, in base alla quale si decide se proseguire o se terminare il ciclo; nel secondo si 

esegue una volta il ciclo e quindi si verifica una condizione per decidere se ripeterlo o se uscire. 

361.4 Comandi utili negli script 

Alcuni comandi sono particolarmente utili all’interno di script dell’interprete dei comandi. 

Vengono descritti brevemente nelle sezioni seguenti. 

361.4.1 REM 

REM commento 

I commenti negli script dell’interprete dei comandi si indicano attraverso un comando apposito: 

‘REM’. Il funzionamento è evidente: tutto quello che segue il comando, fino alla fine della riga, 

viene ignorato. 

Alcune edizioni del Dos hanno introdotto anche l’uso del punto e virgola, come simbolo per 

indicare l’inizio di un commento. Segue un esempio tipico di utilizzo di questo comando: 

REM 

REM (c) 2000 Pinco pallino 

REM 

361.4.2 ECHO 

ECHO [ON|OFF] 

ECHO stringa 

Il comando interno ‘ECHO’ ha un significato duplice: da una parte consente di visualizzare un testo; 

dall’altra controlla la visualizzazione dei comandi contenuti in uno script. Infatti, si distingue 

il fatto che l’eco dei comandi sia attivo o meno. utilizzando il comando ‘ECHO’ senza argomenti, 

si ottiene l’informazione sul suo stato di attivazione. Di solito si disattiva l’eco dei comandi negli 

script.

Dos: script dell’interprete dei comandi 119 

Per disattivare l’eco di un comando particolare, senza disattivare l’eco in generale, basta 

inserire inizialmente il simbolo ‘@’. 


• @ECHO OFF 

Disattiva l’eco dei comandi, facendo in modo che anche questo comando non venga 

visualizzato (si usa per questo il simbolo ‘@’). 

• ECHO Premi un tasto per continuare 

Mostra un messaggio per spiegare come comportarsi. 

361.4.3 PAUSE 

PAUSE 

Il comando interno ‘PAUSE’ sospende l’esecuzione di uno script in attesa della pressione di un 

tasto. Il comando emette attraverso lo standard output un messaggio di avvertimento in tal senso. 

Di solito, per evitare di vedere tale messaggio, si ridirige lo standard output in un file nullo. 

L’esempio seguente, prima mostra un messaggio in cui si avverte che per proseguire occorre 

premere un tasto, quindi si usa il comando ‘PAUSE’ che sospende l’esecuzione dello script, senza 

però mostrare altri messaggi: 

ECHO Premere un tasto per proseguire 

PAUSE > C:\NULL 

361.4.4 CLS 

CLS 

Il comando interno ‘CLS’ ripulisce lo schermo. Si utilizza senza argomenti. 

361.4.5 CHOICE 

CHOICE [opzioni] [testo_di_invito] 

Il comando ‘CHOICE’ serve a presentare una richiesta per l’inserimento di una lettera, tra un elenco 

determinato. La pressione del tasto corrispondente alla lettera scelta, da parte dell’utilizzatore, 

provoca la conclusione del funzionamento di ‘CHOICE’ che restituisce un valore corrispondente 

alla scelta: zero per la prima lettera, uno per la seconda,... 

Si osservi che l’ultimo argomento rappresenta un messaggio che serve all’utente per comprendere 

il senso della scelta che sta facendo.




Permette di fissare l’elenco di lettere che possono essere usate 

/C:lettera[lettera...] 

nella risposta. Se non si indica questa opzione, la scelta sarà 

solo tra ‘y’ e ‘n’. 

Questa opzione fa in modo di escludere la visualizzazione 

delle lettere che possono essere scelte. In questo modo si fa 

/N 

affidamento esclusivamente sul testo indicato come ultimo 

argomento. 

Distingue tra maiuscole e minuscole per quanto riguarda le 

/S 

lettere tra cui scegliere. 

L’esempio seguente, salta a un punto differente dello script in base alla scelta di una lettera da «a» 

a «f». Si osservi che non sarebbe possibile eseguire l’analisi secondo una sequenza differente, 

perché ‘IF ERRORLEVEL’ prende in considerazione tutti i valori di uscita maggiori o uguali a 

quanto indicato nella condizione. 

CHOICE /C:abcdef Inserisci una lettera 

IF ERRORLEVEL 5 GOTO :f 

IF ERRORLEVEL 4 GOTO :e 

IF ERRORLEVEL 3 GOTO :d 

IF ERRORLEVEL 2 GOTO :c 

IF ERRORLEVEL 1 GOTO :b 

IF ERRORLEVEL 0 GOTO :a 

... 


Dos: gestione della memoria centrale 

Capitolo 362 

Quando è nato il Dos non si prevedeva l’uso di memoria centrale oltre il singolo mebibyte (1 Mibyte). 

In base a questa considerazione veniva articolata l’architettura hardware degli elaboratori 

«XT» e poi «AT», dove si prevedeva l’uso di un massimo di 640 Kibyte di memoria centrale, 

riservando la parte successiva, fino alla fine di 1 Mibyte, per la memoria video e altri dispositivi 

fisici. 

In questo senso, il Dos tradizionale può operare con un massimo di 640 Kibyte di memoria 

centrale; per sfruttarne di più occorrono degli accorgimenti non facili da applicare. 

362.1 Gestione particolare 

Per sfruttare la memoria oltre il primo mebibyte, si fa uso normalmente di due programmi, avviati 

attraverso ‘CONFIG.SYS’, prima ancora dell’interprete di comandi. Si tratta di ‘HIMEM.SYS’ e di 

‘EMM386.EXE’. In generale, le cose si fanno nel modo seguente: 

DEVICE=C:\DOS\HIMEM.SYS 

DEVICE=C:\DOS\EMM386.EXE 

Il primo dei due programmi può essere utilizzato a partire da architetture i286, mentre il secondo 

si può inserire solo a partire da architetture i386. 

‘HIMEM.SYS’ è in grado di utilizzare solo una piccola parte di memoria aggiuntiva, mentre 

‘EMM386.EXE’ permette teoricamente di sfruttare tutto il resto. 

In generale, è molto difficile la gestione ottimale della memoria centrale, perché le applicazioni 

si comportano in maniera differente. Di solito si possono solo fare dei tentativi. 

362.2 Comandi appositi 

Per sfruttare la memoria centrale che supera la soglia convenzionale, sono disponibili alcuni comandi 

specifici. In generale, si comincia dalla configurazione con il file ‘CONFIG.SYS’: dopo 

l’attivazione dei gestori speciali della memoria, è possibile indicare di collocare parte dell’interprete 

dei comandi e dello spazio richiesto dai programmi residenti in memoria, oltre il limite 

della memoria convenzionale: 

DOS=HIGH,UMB 

In seguito, sempre nell’ambito del file ‘CONFIG.SYS’, si può richiedere esplicitamente l’avvio di 

programmi nella memoria alta attraverso la direttiva ‘DEVICEHIGH’, come si vede nell’esempio 

seguente: 

DEVICEHIGH=C:\MOUSE\MOUSE.SYS /2 

Per quanto riguarda i programmi avviati attraverso l’interprete dei comandi, è disponibile il 

comando ‘LH’, ovvero ‘LOADHIGH’: 

LH programma [argomenti_del_programma] 

LOADHIGH programma [argomenti_del_programma] 

Per esempio, si potrebbe tentare di avviare in questo modo il programma di gestione della tastiera: 

C:\>LH KEYB IT 

121


362.3 Verifica 

Il Dos offre un solo programma molto semplice per la verifica dell’utilizzo della memoria: ‘MEM’. 

MEM [opzioni] 

Se ‘MEM’ viene usato senza opzioni, visualizza brevemente la quantità di memoria utilizzata rispetto 

al totale disponibile. È interessante l’opzione ‘/CLASSIFY’, attraverso la quale è possibile 

distinguere l’utilizzo della memoria da parte dei programmi residenti; inoltre è interessante 

l’opzione ‘/FREE’, con cui si hanno informazioni dettagliate sulla memoria libera. 

Le opzioni disponibili del comando ‘MEM’ variano molto da una realizzazione all’altra. In 

generale conviene verificare prima di utilizzarlo, per conoscere le possibilità effettive. 


FreeDOS 

Capitolo 363 

FreeDOS è il nome di un progetto per la realizzazione di un sistema operativo libero compatibile 

con il Dos. Il Dos, per quanto limitato, ha delle caratteristiche che lo possono rendere ancora 

interessante per elaboratori con architettura i86 particolarmente poveri di risorse, come nel caso 

dei sistemi cosiddetti embedded. 

363.1 Installazione 

L’installazione della distribuzione standard di FreeDOS è abbastanza semplice. Si parte da un dischetto 

di avvio, con il quale si predispone la partizione e la si inizializza, quindi si prosegue con 

il programma di installazione che chiede l’inserimento dei dischetti successivi. La riproduzione 

del dischetto di avvio a partire dalla sua immagine avviene come al solito attraverso il programma 

‘RAWRITE.EXE’, oppure per mezzo di un sistema Unix nei modi già mostrati per GNU/Linux 

e altri sistemi simili. 

C:\>RAWRITE FULL.BIN A: 

L’esempio mostra l’uso di ‘RAWRITE.EXE’ per ottenere un dischetto dall’immagine 

rappresentata dal file ‘FULL.BIN’. 

La distribuzione standard di FreeDOS si compone di un file-immagine del dischetto di avvio, 

che potrebbe chiamarsi ‘FULL.BIN’, e da una serie di file con estensione ‘.ZIP’ che servono 

per ottenere i dischetti successivi. Ognuno di questi file compressi rappresenta il contenuto di un 

dischetto, che quindi deve essere prima estratto: 

C:\>A: 

A:\>UNZIP C:\TMP\BASE1.ZIP 

L’esempio mostra in breve il procedimento: ci si sposta nell’unità ‘A:’ e da lì si estrae il file 

compresso che probabilmente si trova da qualche parte nel disco fisso. 

Questi file compressi rappresentano una raccolta di applicativi e hanno una struttura particolare 

che viene descritta nel seguito. 

• nome_raccolta.1 

L’archivio compresso deve contenere un file che rappresenta il nome della raccolta, con 

un’estensione numerica. La raccolta potrebbe essere suddivisa in più archivi ed è per questo 

che si usa l’estensione numerica, che indica il numero di sequenza dell’archivio nell’ambito 

della raccolta. 

Il file contiene l’elenco dei pacchetti contenuti, con l’indicazione dell’opzione di installazione 

predefinita o meno. Si osservi l’estratto seguente (la lettera «Y» rappresenta la 

conferma all’installazione predefinita): 

asgn14x: Y 

attr063x: Y 

bwb210x: Y 

choic20x: Y 

• nome_raccolta.END 

Si tratta di un file vuoto, che rappresenta la conclusione della raccolta, nel senso che non ci 

sono altri dischetti ulteriori. 

123


• nome_pacchetto.LSM 

Si tratta di un file che descrive un pacchetto applicativo. Quello che segue è l’esempio del 

contenuto del file ‘DELTR10X.LSM’: 

Begin3 

Title: deltree 

Version: 1.02b 

Entered-date: 27 Jul 1999 

Description: Delete a directory and all directories under it 

Keywords: freedos delete 

Author: raster@highfiber.com 

Maintained-by: raster@highfiber.com 

Primary-site: http://www.highfiber.com/~raster/freeware.htm 

Alternate-site: www.freedos.org 

Original-site: http://www.highfiber.com/~raster/freeware.htm 

Platforms: dos 

Copying-policy: GPL 

End 

• nome_pacchetto.ZIP 

Si tratta dell’archivio compresso che contiene i file dell’applicativo. In base alla struttura 

standard di FreeDOS, potrebbe distribuirsi nelle directory ‘BIN\’, ‘DOC\’ e ‘HELP\’. 

Dopo aver preparato i dischetti, si può procedere con l’avvio del sistema attraverso il dischetto 

di avvio; quindi si passa a predisporre la partizione: 

A:\>FDISK 

Purtroppo, il kernel di FreeDOS non è in grado di gestire partizioni più grandi di 512 Mibyte, 

per cui occorre tenerne conto durante l’uso di ‘FDISK’. Dopo aver preparato la partizione la si 

inizializza: 

A:\>FORMAT C: /U 

Successivamente si trasferisce il sistema, con il comando ‘SYS’: 

A:\>SYS C: 

Infine si avvia il programma di installazione che provvederà a chiedere la sostituzione dei 

dischetti: 

A:\>INSTALL 

363.2 Impostazione e configurazione 

Da quanto è stato descritto sull’installazione di FreeDOS si intende che, pur trattandosi di un 

sistema Dos, si cerca di introdurre qualche buona idea proveniente da Unix. In particolare, è 

prevista una struttura per la collocazione dei file: 

• ‘BIN\’ per contenere i file eseguibili; 

• ‘DOC\’ per contenere la documentazione che si articola in altre sottodirectory successive, 

come avviene con GNU/Linux 

• ‘HELP\’ per contenere i file della guida interna relativa.

FreeDOS 125 

Questa struttura potrebbe essere collocata anche a partire da un punto differente della radice 

dell’unità, in base alle scelte fatte in fase di installazione. In ogni caso, occorre poi predisporre 

coerentemente alcune variabili di ambiente: ‘PAGER’ per indicare il programma da utilizzare per 

lo scorrimento dei file delle guide; ‘HELPPATH’ per indicare la directory contenente i file delle 

guide; ‘EMACS’ per indicare la directory contenente i file di Emacs. 

In condizioni normali, gli applicativi FreeDOS vengono installati a partire dalla directory 

‘\FDOS\’, per cui la configurazione si traduce nelle istruzioni seguenti nel file ‘AUTOEXEC.BAT’: 

SET PAGER=MORE 

SET HELPPATH=C:\FDOS\HELP 

SET EMACS=C:\FDOS\EMACS\ 

In base alla documentazione originale, nel caso della variabile di ambiente ‘EMACS’ deve essere 

indicata la barra obliqua inversa finale. 

A seconda della distribuzione di FreeDOS, può darsi che il file ‘CONFIG.SYS’ debba essere 

sostituito con uno avente un nome differente. Potrebbe trattarsi del file ‘FDCONFIG.SYS’. 

363.3 RxDOS 

RxDOS è un altro progetto analogo a FreeDOS, scritto in maniera indipendente. È provvisto di 

un proprio interprete dei comandi e non ha ancora un suo sistema di installazione. Per provare il 

funzionamento di RxDOS ci si può avvalere solo di un dischetto, realizzato nel modo seguente: 

1. si inizializza il dischetto in qualche modo, assicurando che alla fine sia disponibile un 

file system Dos-FAT; 1 

2. si esegue lo script ‘MAKEBOOT.BAT’, il cui scopo è la predisposizione del settore di avvio 

nel dischetto; 

3. si copiano ordinatamente nel dischetto i file elencati qui sotto. 

• ‘RXDOSBIO.SYS’ 

• ‘RXDOS.SYS’ 

• ‘RXDOSCMD.EXE’ 

• ‘RXDVDISK.SYS’ 

• ‘AUTOEXEC.DEF’ 

• ‘CONFIG.DEF’ 


• FreeDOS 

 

Appunti di informatica libera 2003.06.29 --- Copyright © 2000-2003 Daniele Giacomini -- daniele @ swlibero.org 

1 Il dischetto non deve avere l’etichetta, ovvero non deve avere un nome.

Progetto GNUish 

Capitolo 364 

Il progetto «GNUish» è una sorta di derivazione povera del progetto GNU, con lo scopo di 

rendere disponibile parte del software che compone il sistema GNU anche nei sistemi Dos. Il 

progetto ha un’importanza molto piccola, ma viene ancora mantenuto. Evidentemente, date le 

peculiarità dei sistemi Dos, il software che viene adattato non può avere le stesse potenzialità che 

ha invece in un sistema Unix. 

I siti principali da cui si può ottenere copia del materiale prodotto dal progetto GNUish sono 

quelli elencati all’interno dal documento seguente: 

• 

In questo capitolo viene mostrato il funzionamento di alcuni programmi, nell’ambito del sistema 

Dos, per i quali è il caso di spendere qualche parola. 

364.1 Programmi di servizio vari 

Molti dei programmi di servizio del progetto GNU sono disponibili anche per Dos. Tuttavia, è il 

caso di osservare alcune particolarità che possono confondere chi è abituato a usare sistemi Dos. 

La prima cosa da notare è il fatto che i percorsi si possono indicare secondo lo stile Unix, 

utilizzando barre oblique normali. Per esempio: 

C:\>MV C:/PRIMO/SECONDO C:/TERZO 

Diversamente, utilizzando lo stesso comando, ma secondo l’indicazione tipica del Dos, la cosa 

può funzionare ugualmente, oppure si possono presentare delle segnalazioni di errore. Bisogna 

tenere presente la possibilità. 

Un’altra cosa da notare è l’uso dei caratteri jolly, che con questi programmi segue la logica 

di Unix, dove l’asterisco indica qualunque nome, senza trattare in modo speciale il punto di 

separazione dell’estensione: 

C:\>CP C:/PRIMO/SECONDO/* C:/TERZO 

L’esempio mostra proprio questo fatto: vengono copiati tutti i file contenuti nella directory ‘C:\ 

PRIMO\SECONDO\’, nella directory ‘C:\TERZO\’. 

364.2 Gnuplot 

Il funzionamento generale di Gnuplot è descritto nel capitolo 337. Per funzionare, questa edizione 

di Gnuplot richiede due file: ‘GNUPLOT.EXE’ e ‘GNUPLOT.GIH’. Il primo dei due è l’eseguibile in 

grado di gestire la grafica VGA, mentre il secondo contiene le informazioni della guida interna. 

Se si vuole accedere alla guida interna, è necessario che il file ‘GNUPLOT.GIH’ si trovi nella 

directory corrente. Forse è sufficiente utilizzare il comando ‘APPEND’ del Dos per risolvere il 

problema. 

126

Progetto GNUish 127 

364.3 Spreadsheet Calculator 

Il funzionamento generale di SC (Spreadsheet Calculator) è descritto nel capitolo 336. La versione 

per Dos funziona correttamente (è sufficiente disporre dell’eseguibile ‘SC.EXE’), riconoscendo 

anche l’uso dei tasti freccia, per cui non si è più costretti a utilizzare le lettere ‘h’, ‘j’, ‘k’ e 

‘l’. 

364.4 Ispell 

Ispell è descritto in generale nel capitolo 273. Questa edizione di Ispell richiede due file: 

‘ISPELL.EXE’ e ‘ISPELL.DIC’. Come si intuisce, il primo è l’eseguibile, mentre il secondo 

è il file del dizionario. Purtroppo, il file ‘ISPELL.DIC’ non è sostituibile o eliminabile; l’unica 

cosa che si può fare è predisporre un dizionario personalizzato che si richiama con l’opzione 

‘-p’. 

ISPELL [-d dizionario_standard] [-p dizionario_personale] file 

Quella che si vede è la sintassi essenziale su cui si può contare nell’edizione di Ispell per Dos. Il 

file del dizionario standard, ‘ISPELL.DIC’, può essere collocato nella stessa directory in cui si 

trova il file eseguibile; altrimenti si deve usare l’opzione ‘-d’ per indicarlo esplicitamente. 

Il dizionario personale è un file di testo normale (Dos), che può anche essere creato inizialmente 

dallo stesso Ispell. L’esempio seguente, mostra il caso in cui si voglia analizzare il file 

‘LETTERA.TXT’ attraverso il dizionario standard e il dizionario personale ‘VOCAB.TXT’. Se il 

file ‘VOCAB.TXT’ non dovesse esistere, verrebbe creato per l’occasione. 

C:\LETTERE>ISPELL -p VOCAB.TXT LETTERA.TXT 

364.5 Perl 

Perl è un linguaggio di programmazione descritto in generale a partire dal capitolo 299. L’edizione 

Dos dell’interprete Perl richiede due file: ‘PERL.EXE’ e ‘PERLGLOB.EXE’. È sufficiente che 

questi siano disponibili nei percorsi degli eseguibili della variabile di ambiente ‘PATH’. 

Bisogna tenere a mente che si tratta di una versione molto vecchia del linguaggio, per cui alcune 

novità non saranno disponibili. Inoltre, l’avvio dei programmi può avvenire solo richiamando 

direttamente l’interprete: 

C:\ESERCIZI>PERL FATT.PL 5 

L’esempio mostra l’avvio del programma Perl contenuto nel file ‘FATT.PL’, che riceve un 

argomento costituito dal numero cinque. 


• François Pinard, GNUish MSDOS Project 

 


The valuable DOS Freeware page 

Links to valuable free Dos programs working on low equipped computers. 

Chapter 365 

This material appeared originally at ‘http://www.geocities.com/SiliconValley/ 

7737/’, in 1996. Now it is incorporated inside the Italian document ‘‘Appunti 

di informatica libera’’, and it might be reached at the URI . 

Questo materiale è apparso in origine, nel 1996, presso ‘http://www.geocities.com/ 

SiliconValley/7737/’. Adesso viene incorporato nel documento «Appunti di 

informatica libera» e può essere raggiunto attraverso l’URI . L’intento dell’autore è solo quello di continuare a curare 

un vecchio lavoro che potrebbe essere ancora utile, nonostante si tratti di riferimenti a 

software in parte libero e in parte solo gratuito, oltre che evidentemente obsoleto. 

365.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

365.2 OS and GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 

365.3 Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 

365.4 Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 

365.5 Compilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

365.6 Typesetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

365.7 More Dos software sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

365.8 Search engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

365.1 Introduction 

The Dos operating system meant much for many people. Today, proprietary Dos-like operating 

systems seem to be no more developed. In this situation, the only possible future for Dos is the 

‘‘free’’ software, and it is not just a matter of money anymore. 

Unfortunately, ‘‘free’’ is a word with many meanings. Today, this is still the biggest obstacle to 

the future of the Dos world. There is so much software for Dos, with so many different license 

agreements. The typical Dos user doesn’t mind to it. But this problem prevents the realization of 

big serious projects based on it. 

Today, the Dos world needs philosophy, and the GNU idea is still the right one (). 

The author of this space would like to list here only ‘‘free software’’ in the sense stated by the 

Free Software Foundation, but it is impossible, as there isn’t enough good real free software for 

Dos. 

The listed software is meant to work on i286 and below. 

It is attempted to give some kind of classification about the legal condition of the software presented 

here. The definition used might be outdated, or there might be other wrong assumption. 

128

The valuable DOS Freeware page 129 

In particular, the definition ‘‘public domain’’ means here, in most cases, that there is the source, 

but there is no clear license statement. 

Beside the URI links of some FTP services there is an additional ‘‘search link’’ that queries a 

FTP search engine for the same file. These additional links should be used when there are troubles 

with the main links. 

Anyone can link this document anywhere, so, there is no need to ask for it. Anyway, it is better to 

link to this document using at the file name . 

In the future, many links may disappear on this page, because of more selective choices 

concerning software license. 

365.2 OS and GUI 

• FreeDOS 1 

• FreeGEM 2 

365.3 Utility 

archive, backup 

• Gzip 3 - ‘.GZ’ archive compressor and extractor. 

• TAR 4 - portable TAR - DOS/UNIX backup, compressor, with hardware 

support. 

• Untgz 5 - ‘.TGZ’, ‘.TAR’, ‘.GZ’, ‘.ZIP’ file extractor. 

• Info-ZIP 6 - ‘.ZIP’ compatible compression and extraction utility. 

 

• Restaur 7 - Replacement for Dos Restore, 

communication 

• DosFax 8 - Send a fax using Dos command line 

• Bgfax 9 

• Rifs 10 - Disk sharing over a serial line, 

 

1 

FreeDOS GNU GPL 

2 

FreeGEM GNU GPL 

3 

Gzip GNU GPL 

4 

TAR (Dos) public domain 

5 

Untgz GNU GPL 

6 

Info-ZIP free software with special license 

7 

Restaur cannot be sold for profit 

8 

DosFax public domain 

9 

Bgfax promised to become free software 

10 

Rifs cannot be sold for profit


directory, file 

disk 

help 

shell 

system 

text 

See also: 

• WCD 11 - Powerful chdir for Dos and Unix 

• Fips 12 - Non-destructive splitting of hard disk partitions 

• Part 13 - MBR partition manager 

• NG_clone 14 - Norton Guides clone 

 

• DC 15 - The Dos Controller - A Norton Commander clone 

• Cmos 16 - Save/Restore extended C/MOS 

• KGB 17 - Utility to monitor some Dos functions and reporting into a 

log file 

• Vim 18 - VI improved, a small text editor that can handle very big files with low 

RAM 

• Richard L. Green, Free software for Dos 

 

365.4 Network 

packet driver 

11 

WCD GNU GPL 

12 

Fips GNU GPL 

13 

Part public domain 

14 

NG_clone public domain 

15 

DC public domain (no license at all, and no sources) 

16 

Cmos public domain 

17 

KGB public domain 

18 

Vim free software with special license


TCP/IP 

See also: 

• PC/TCP Packet Driver Collection 19 

• WATTCP 20 - TCP/IP library routines 

• DOS PPPD 21 - Dos port of Linux PPP packet driver 

• Comring 22 - packet driver emulating ethernet over serial link(s) 

• WATTCP apps 23 - some common client application using WATTCP library 

• MiniTelnet 24 - TELNET client 

• Bobcat 25 - Text based web browser (derived 

from DosLynx, ) 

• PCroute 26 - IP routing program for IBM PC 

• PPRD 27 - Turn a dedicated PC (XT/AT) into a LPD server 

 

• NCSA Telnet 28 - Telnet, Ftp,... NCSA 

 

• NOS (KA9Q) 29 - A complete mini TCP/IP system 

To use NOS you need documentation, for example the package 

• SSHDOS 30 - SSH client for Dos 

• Talk 31 - Talk client for Dos 

• ABC-nslookup 32 - DNS query clients for Dos 

• Marc S. Ressl, Dos Internet Pages 

 

• Smash-Co Communications, TCP/IP for MS-DOS 

 

19 

Crynwr packet driver collection GNU GPL 

20 

WATTCP free of charge library 

21 

DOS PPPD mixed licenses 

22 

Comring GNU GPL 

23 

WATTCP apps cannot be sold 

24 

MiniTelnet free software with a special license 

25 

Bobcat GNU GPL 

26 

PCroute cannot distribute modifications 

27 

PPRD software non libero: licenza Artistic 

28 

NCSA Telnet public domain 

29 

NOS public domain 

30 

SSHDOS GNU GPL 

31 

Talk GNU GPL 

32 

ABC-nslookup UCB BSD


• The U-M Software Archive 

 

 

365.5 Compilers 

assembler 

batch 

C/C++ 

Perl 

Rexx 

xBase 

See also: 

See the FreeDOS project () for assembler compilers. 

• BAT2EXE 33 - Compile batch files for speed 

See the FreeDOS project () for C and C++ compilers. 

Perl 34 - Practical Extraction Report Language 

• BREXX 35 - Rexx interpreter for Dos/Unix 

• nanoBase 36 - Mini, but nearly complete xBase 

• David Muir Shamoff, Catalog of free compilers and interpreters 

 

365.6 Typesetting 

• Nro 37 - A Nroff implementation for Dos 

 

• Ghostscript 38 - ‘‘GNU’’ original edition - PostScript previewing, conversion, and printing 

 

• emTeX 39 - TeX-LaTeX distribution for Dos 

33 BAT2EXE public domain 

34 Perl GNU GPL or Artistic 

35 BREXX public domain 

36 nanoBase GNU GPL 

37 Nro public domain 

38 Ghostscript GNU GPL 

39 emTeX LPPL but some files have different conditions


365.7 More Dos software sources 

• 

• 

365.8 Search engines 

• 

• 


Clean the Clipper 5.2 

Chapter 366 

A different way to program using Clipper 5.2 without commands, that is, without the file 

‘STD.CH’. 


7737/clipper52clean.html’, in 1996. Now it is incorporated inside the Italian document 

‘‘Appunti di informatica libera’’, and might be reached at the URI . 


SiliconValley/7737/clipper52clean.html’. Adesso viene incorporato nel documento 

«Appunti di informatica libera» e può essere raggiunto attraverso l’URI . L’intento dell’autore è solo quello di conservare un 

vecchio lavoro che potrebbe essere ancora utile, nonostante si tratti di considerazioni su un 

compilatore proprietario, ormai obsoleto. 

366.1 Step 1: try to compile with the /P parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 

366.2 Step 2: understand well the use of code blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136 

366.3 Step 3: understand the object programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

366.3.1 Classes and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 

366.3.2 Class definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

366.3.3 Object creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 

366.3.4 Instantiating an object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

366.3.5 The ‘‘send’’ symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

366.3.6 More about objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

366.4 Step 4: understand the get object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

366.5 Step 5: trying to stop using commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 

366.5.1 ?/?? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

366.5.2 @...BOX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

366.5.3 @...GET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141 

366.5.4 @...SAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

366.5.5 @...TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

366.5.6 APPEND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

366.5.7 APPEND FROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

366.5.8 CLEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

366.5.9 CLOSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

366.5.10 COMMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

366.5.11 CONTINUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 

366.5.12 COPY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 

366.5.13 COUNT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143 

366.5.14 CREATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

134

Clean the Clipper 5.2 135 

366.5.15 DEFAULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144 

366.5.16 DELETE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.17 EJECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.18 ERASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.19 FIND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.20 GO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.21 INDEX ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

366.5.22 JOIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 

366.5.23 KEYBOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 

366.5.24 LABEL FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 

366.5.25 LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 

366.5.26 LOCATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 

366.5.27 PACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146 

366.5.28 QUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

366.5.29 READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

366.5.30 RECALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146 

366.5.31 REINDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

366.5.32 RELEASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

366.5.33 RENAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.34 REPLACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.35 REPORT FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.36 RESTORE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.37 RESTORE FROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.38 RUN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 

366.5.39 SAVE SCREEN TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

366.5.40 SAVE TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

366.5.41 SEEK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

366.5.42 SELECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

366.5.43 SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

366.5.44 SKIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.45 SORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.46 STORE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.47 SUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.48 TOTAL ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.49 UNLOCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.50 UPDATE FROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.51 USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

366.5.52 ZAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 

366.6 Step 6: free yourself from STD.CH - /U . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 

366.7 Step 7: take control over all include files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153


Clipper 5.2, as the xBase tradition imposes, is not an ordered, clear, simple programming language. 

The question is: which is the right way to write a Clipper program? If the intention is not 

to make a xBase program, but a Clipper program, maybe it can be decided that it is better to use 

Clipper without commands. 

366.1 Step 1: try to compile with the /P parameter 

Supposing to compile the file ‘TEST.PRG’ this way: 

C:\>CLIPPER TEST.PRG /P 

It generates a preprocessed output file (‘test.PPO’), that is a source file without comments, 

where commands are translated into real Clipper instructions. That is, all the ‘#COMMAND’ substitution 

are executed and the translation is sent to the ‘.PPO’ file. It may be difficult to read this 

file the first time. 

366.2 Step 2: understand well the use of code blocks 

The code block is a small piece of executable program code that can be stored inside a variable, 

or can be used as a literal constant. The good of it, is that pieces of code may be sent to functions. 

A code block is something like a little user defined function where only a sequence of expressions 

(functions and/or assignments) may appear: no loops, no conditional structures. 

A code block may receive arguments and return a value after execution, just like a function. The 

syntax is the following, where curly brackets are part of the code block: 

{ | [argument_list] | exp_list } 

That is: the argument_list is optional; the exp_list may contain one or more expressions separated 

with a comma. 

For example, calling the following code block will give the string ‘‘hello world’’ as result. 

{ || "hello world" } 

The following code block requires a numeric argument and returns the number passed as argument 

incremented: 

{ | n | n+1 } 

The following code block requires two numeric arguments and returns the sum of the two square 

radix: 

{ | nFirst, nSecond | SQRT(nFirst) + SQRT(nSecond) } 

But code blocks may contain more expressions and the result of the execution of the code block 

is the result of the last expression. The following code block executes in sequence some functions 

and gives ‘‘hello world’’ as a result. 

{ | a, b | functionOne(a), functionTwo(b), "hello world" } 

To start the execution of a code block a function is used: ‘EVAL()’. For example, a code block is 

assigned to a variable and then executed. 

B := { || "hello world" } 

EVAL( B ) == "hello world"


Another example with one parameter. 

B := { | n | n+1 } 

EVAL( B, 1 ) == 2 

Another example with two parameters. 

B := { | nFirst, nSecond | SQRT(nFirst) + SQRT(nSecond) } 

EVAL( B, 2, 4 ) == 20 

And so on. 

366.3 Step 3: understand the object programming 

Clipper 5.2 do not permit to create objects, but it gives some good objects to use: ‘GET’ and 

‘TBROWSE’. Before starting to clean programming from commands, it is necessary to understand 

how to use well the Clipper objects. 

366.3.1 Classes and methods 

A class defines the structure of a ‘‘black box’’, that is a data container; a method is an action 

to make on a piece of data contained inside the black box. There is no way to reach the data 

contained inside the black box without a method. 

The black box can be called object. 

The methods may be seen as they where special functions which interact with a specific piece of 

data contained inside the object. 

366.3.2 Class definition 

Supposing that Clipper permits to define classes (unluckily only predefined classes can be used), 

the hypothetical syntax could be: 

CLASS ClassName [FROM ParentClass] 

VAR Var1 [,Var2[,...VarN]] 

METHOD {method_definition_1} [, ...{method_definition_n} ] 

ENDCLASS 

This way, the class defines a group of variables and a group of method to use with these variables. 

366.3.3 Object creation 

The presence of classes permits to create objects: the black boxes. 

Variable_name := ClassName 

This way, a variable contains (is) an object. Please note that inside Clipper, an object may be 

generated also from a function, that is, a function can return an object. This way the example can 

be: 

Variable_name := classfunction( ... ) 

The next problem is to handle this object.


366.3.4 Instantiating an object 

As already stated before, methods are used to handle data contained inside an object. This is said 

to be instantiating an object. Clipper permits also to handle directly (apparently without methods) 

some variables contained inside objects. These are called ‘‘Exported Instance Variables’’. So, an 

object can be instantiated this way: 

object:exported_instance_variable := new_value 

object:method() 

An exported instance variable may be read and/or modified depending on the allowed access to it; 

a method, inside Clipper, is something like a function with or without parameters (if parameters 

are present, these are usually used to modify data inside the object), that normally returns a value. 

366.3.5 The ‘‘send’’ symbol 

To instantiate an object or simply to access an exported instance variable, the ‘‘send’’ symbol 

(colon) is used. 

366.3.6 More about objects 

If this is not enough to understand objects inside Clipper, the following document should be read: 

Peter M. Freese, o:Clip - An Object Oriented Extension to Clipper 5.01 1991, CyberSoft 

 

366.4 Step 4: understand the get object 

What happens with a command like the following: 

@ nTop, nLeft GET Var 

A get object is created containing all the necessary information for editing the variable Var at 

the screen position nTop, nLeft. After that, this get object is added to a get objects array (usually 

called ‘GetList’). The get objects array will contain all the get objects used during a ‘READ’. 

So, what happens when a ‘READ’ command is encountered. The get objects array (‘GetList’) is 

read and the editing of all get objects is executed. After that, the get objects array is cleared. 

This method hides what Clipper really makes. The suggestion here is to create a ‘GET()’ function 

that will substitute the ‘@...GET’ command and to use the ‘READMODAL()’ function to read the get 

objects array. Here is an example of it: 

function GET( aoGet, nRow, nCol, bVar, cGetPicture, 

cColorString, bPreValid, bPostValid ) 

// declare a local get object 

local oGet 

// create the get object using the function GETENV() 

oGet := GETENV( nRow, nCol, bVar, NIL, cGetPicture, cGetColor ) 

// send to the get object the pre-validation condition code block (WHEN) 

oGet:preBlock := bPreValid


// send to the get object the post-validation condition code block (VALID) 

oGet:postBlock := bPostValid 

// display the get on the screen using the display() method 

oGet:display() 

// add the get object to the get objects array 

AADD( aoGet, oGet ) 

return NIL 

• ‘aoGet’ is the get objects array (so here is explicitly passed). This get objects array is 

modified (grown) and there is no need to return it as inside Clipper, arrays are always 

passed by reference to functions. 

• ‘nRow’ and ‘nCol’ are the screen coordinates where the get field should appear at, as it 

works with the ‘@...GET’ command. 

• ‘bVar’ is a special code block that permits the editing of a variable. If the variable ‘Var’ is 

to be edited, the code block is: 

{ |x| iif( pcount() > 0, Var := x, Var } 

• ‘cGetPicture’ is the picture to use: same as the ‘@...GET’ command. 

• ‘cColorString’ is the color string to use: same as the ‘@...GET’ command. 

• ‘bPreValid’ is a code block containing the condition that must be valid before the cursor 

can reach this get field. It is equivalent to the ‘WHEN’ condition used with the ‘@...GET’ 

command, but it must be converted into a code block. For example, if the condition is 

‘A > B’, the code block is ‘{|| A > B}’ 

• ‘bPostValid’ is a code block containing the condition that must be valid before the cursor 

can leave this get field. It is equivalent to the ‘VALID’ condition used with the ‘@...GET’ 

command, but it must be converted into a code block. For example, if the condition is 

‘A > B’, the code block is ‘{|| A > B}’ 

If there is a get function like the above one, screen I/O may be performed like the following 

example: 

function do_some_editing() 

// define a variable to use as a get objects array 

// and initialise it to the empty array 

local aoGet := {} 

... 

... 

// add a new get object to the get objects array 

get(; 

aoGet,; 

10, 10,; 

{ |x| iif( pcount() > 0, myVariable := x, myVariable },; 

"@s30@",; 

"gb+/b, n/w, n, n, w/n",; 

{ || .T. },; 

{ || .T. }; 

)


... 

// read the get objects array 

readmodal( aoGet ) 

// clear the get objects array 

aoGet := {} 

... 

return ... 

If the function ‘GET()’ is not liked, the above I/O may be done as it follows: 

function do_some_editing() 

// define a variable to use as a get object 

local aoGet 

// define a variable to use as a get objects array 

// and initialise it to the empty array 

local aoGet := {} 

... 

... 

// add a new get object to the get objects array 

oGet :=; 

GETENV(; 

10, 10,; 

{ |x| iif( pcount() > 0, myVariable := x, myVariable },; 

NIL,; 

"@s30@",; 

"gb+/b, n/w, n, n, w/n",; 

) 

AADD( aoGet, oGet ) 

... 

// read the get objects array 

readmodal( aoGet ) 

// clear the get objects array 

aoGet := {} 

... 

return ... 

366.5 Step 5: trying to stop using commands 

To stop using commands, it is important to understand how commands are or may be translated 

into functions. Sometimes Clipper uses some undocumented functions: these are functions that 

start with a underline.


366.5.1 ?/?? 

? [exp_list] 

qout([exp_list]) 

?? [exp_list] 

qqout([exp_list]) 

366.5.2 @...BOX 

@ nTop, nLeft, nBottom, nRight BOX cnBoxString [COLOR cColorString] 

dispbox(nTop, nLeft, nBottom, nRight, [cnBoxString], [cColorString]) 

366.5.3 @...GET 

@ nTop, nLeft GET Var [PICTURE cGetPicture] [COLOR cColorString] [WHEN lPreExpression] ←↪ 

↩→[VALID lPostExpression] 

setpos(nTop, nLeft) 

aadd( GetList, _GET_( Var, "Var", cGetPicture, [{|| lPostExpression}],←↪ 

↩→[{|| lPreExpression}] ):display() ) atail(GetList):colorDisp(cColorString) 

This is the command substitution made automatically, but it shouldn’t be used to make clean 

programs. The step 4 (366.1) suggests to create a get function. 

366.5.4 @...SAY 

@ nTop, nLeft SAY exp [COLOR cColorString] 

devpos(nTop, nLeft) 

devout(exp [, cColorString]) 

@ nTop, nLeft SAY exp PICTURE cSayPicture [COLOR cColorString] 


devoutpic(exp, cSayPicture, [cColorString]) 

366.5.5 @...TO 

@ nTop, nLeft TO nBottom, nRight DOUBLE [COLOR cColorString] 

dispbox(nTop, nLeft, nBottom, nRight, 2 [,cColorString]) 

@ nTop, nLeft TO nBottom, nRight [COLOR cColorString] 


@ nTop, nLeft CLEAR [TO nBottom, nRight] 

scroll([nTop], [nLeft], [nBottom, nRight]) 

setpos(nRow, nCol)


366.5.6 APPEND 

APPEND BLANK 

dbappend() 

366.5.7 APPEND FROM 

APPEND FROM xcFile [FIELDS idField_list] [scope] [WHILE lCondition]←↪ 

↩→[FOR lCondition] [VIA xcDriver] 

__dbApp( cFileName, [acFields], [bForCondition], [bWhileCondition], [nNextRecords],←↪ 

↩→[nRecord], [lRest], [cDriver] ) 

APPEND FROM xcFile [FIELDS idField_list] [scope] [WHILE lCondition] [FOR lCondition]←↪ 

↩→DELIMITED xcDelimiter 

__dbDelim( .f., cFileName, [cDelimiter], [acFields], [bForCondition], [bWhileCondition] 

,←↪ 

↩→[nNextRecords], [nRecord], [lRest] ) 

APPEND FROM xcFile [FIELDS idField_list] [scope] [WHILE lCondition]←↪ 

↩→[FOR lCondition] SDF 

__dbSDF( .f., cFileName, [acFields], [bForCondition], [bWhileCondition], [nNextRecords] 

,←↪ 

↩→[nRecord], [lRest] ) 

366.5.8 CLEAR 

CLEAR 

Scroll() 

SetPos(0,0) 

ReadKill(.T.) 

GetList := {} 

CLEAR GETS 

ReadKill(.T.) 

GetList := {} 

CLEAR SCREEN | CLS 

Scroll() 

SetPos(0,0) 

366.5.9 CLOSE 

CLOSE 

dbCloseArea() 

CLOSE idAlias 

idAlias->( dbCloseArea() ) 

CLOSE ALTERNATE 

Set(19, "") 

CLOSE DATABASES 

dbCloseAll() 

CLOSE INDEXES 

dbClearIndex()


366.5.10 COMMIT 

COMMIT 

dbCommitAll() 

366.5.11 CONTINUE 

CONTINUE 

__dbContinue() 

366.5.12 COPY 

COPY FILE xcSourceFile TO xcTargetFile|xcDevice 

__CopyFile( cSourceFile, cTargetFile|cDevice ) 

COPY STRUCTURE [FIELDS idField_list] TO xcDatabase 

__dbCopyStruct( cDatabase, [acFields] ) 

COPY STRUCTURE EXTENDED TO xcExtendedDatabase 

__dbCopyXStruct( cExtendedDatabase ) 

COPY TO xcFile [FIELDS idField_list] [scope] [WHILE lCondition]←↪ 

↩→[FOR lCondition] [VIA xcDriver] 

__dbCopy( cFileName, [acFields], [bForCondition], [bWhileCondition], [nNextRecords],←↪ 

↩→[nRecord], [lRest], [cDriver] ) 

COPY TO xcFile [FIELDS idField_list] [scope] [WHILE lCondition] [FOR lCondition]←↪ 

↩→DELIMITED xcDelimiter 

__dbDelim( .t., cFileName, [cDelimiter], [acFields], [bForCondition], [bWhileCondition] 

,←↪ 


COPY TO xcFile [FIELDS idField_list] [scope] [WHILE lCondition]←↪ 

↩→[FOR lCondition] SDF 

__dbSDF( .t., cFileName, [acFields], [bForCondition], [bWhileCondition], [nNextRecords] 

,←↪ 

↩→[nRecord], [lRest] ) 

366.5.13 COUNT 

COUNT TO idVar [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 

↩→[RECORD nRecord] [REST] [ALL] 

dbeval( {||idVar:=idVar+1}, {||lForCondition}, {||lWhileCondition},←↪ 

↩→nNextRecords, nRecord, lRest )


366.5.14 CREATE 

CREATE xcDatabase FROM xcExtendedDatabase [NEW] [ALIAS cAlias] [VIA cDriver] 

__dbCreate( cDatabase, cExtendedDatabase, [cDriver], [lNew], [cAlias] ) 

366.5.15 DEFAULT 

DEFAULT xVar TO xDefaultValue 

if xVar == NIL 

xVar := xDefaultValue 

end 

366.5.16 DELETE 

DELETE 

dbDelete() 

DELETE [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {||dbDelete()}, {||lForCondition}, {||lWhileCondition},←↪ 

↩→nNextRecords, nRecord, lRest ) 

DELETE FILE xcFile 

ferase( cFile ) 

366.5.17 EJECT 

EJECT 

qqout( chr(13) ) 

366.5.18 ERASE 

ERASE xcFile 


366.5.19 FIND 

FIND xcSearchString 

dbSeek( cSearchString ) 

366.5.20 GO 

GO[TO] nRecord 

dbgoto(nRecord) 

GO[TO] BOTTOM 

dbGoBottom() 

GO[TO] TOP 

dbgotop()


366.5.21 INDEX ON 

INDEX ON expKey TO xcIndexName [UNIQUE] [FOR lForCondition]←↪ 

↩→[WHILE lWhileCondition] [[EVAL lEvalCondition] [EVERY nRecords]] [ASCENDING| 

DESCENDING] 

ordCondSet( [cForCondition], [bForCondition], , [bWhileCondition],←↪ 

↩→[bEvalCondition], [nRecords], RECNO(), , , , lDescending ) 

ordCreate( cIndexName, , cExpKey, bExpKey, lUnique ) 

366.5.22 JOIN 

JOIN WITH xcAlias TO xcDatabase [FOR lCondition] [FIELDS idField_list] 

__dbJoin( cAlias, cDatabase, [acFields], [bForCondition] ) 

366.5.23 KEYBOARD 

KEYBOARD cString 

__Keyboard( [cString] ) --> NIL 

366.5.24 LABEL FORM 

LABEL FORM xcLabel [TO PRINTER] [TO FILE xcFile] [NOCONSOLE] [scope]←↪ 

↩→[WHILE lCondition] [FOR lCondition] [SAMPLE] 

__LabelForm( cLabel, [lToPrinter], [cFile], [lNoConsole],←↪ 

↩→[bForCondition], [bWhileCondition], [nNextRecords], [nRecord],←↪ 

↩→[lRest], [lSample] ) 

366.5.25 LIST 

LIST exp_list [TO PRINTER] [TO FILE xcFile] [scope]←↪ 

↩→[WHILE lCondition] [FOR lCondition] [OFF] 

__dbList( [lToDisplay], abListColumns, [lAll], [bForCondition], [bWhileCondition],←↪ 

↩→[nNextRecords], [nRecord], [lRest], [lToPrinter], [cFileName] ) 

366.5.26 LOCATE 

LOCATE [scope] FOR lCondition [WHILE lCondition] 

__dbLocate( [bForCondition], [bWhileCondition], [nNextRecords], [nRecord], [lRest] )


366.5.27 PACK 

PACK 

__dbPack() 

366.5.28 QUIT 

QUIT 

__Quit() 

366.5.29 READ 

READ 

ReadModal(GetList) 

GetList := {} 

READ SAVE 


366.5.30 RECALL 

RECALL 

dbRecall() 

RECALL [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {||dbRecall()}, {||lForCondition}, {||lWhileCondition},←↪ 


366.5.31 REINDEX 

REINDEX [EVAL lEvalCondition] [EVERY nRecords] 

ordCondSet(, , , , [bEvalCondition], [nRecords], , , , , , , ) 

ordListRebuild() 

366.5.32 RELEASE 

RELEASE idMemvar 

__MXRelease( "idMemvar" ) 

RELEASE ALL 

__MRelease("*", .t.) 

RELEASE ALL LIKE skeleton 

__MRelease( "skeleton", .t. ) 

RELEASE ALL EXCEPT skeleton 

__MRelease( "skeleton", .F. )


366.5.33 RENAME 

RENAME xcOldFile TO xcNewFile 

frename( cOldFile, cNewFile ) 

366.5.34 REPLACE 

REPLACE idField1 WITH exp1 [, idField2 WITH exp2...]←↪ 

↩→[FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {|| idField1 := exp1 [, idField2 := exp2...]},←↪ 

↩→{||lForCondition}, {||lWhileCondition}, nNextRecords,←↪ 

↩→nRecord, lRest ) 

REPLACE idField1 WITH exp1 

idField1 := exp1 

366.5.35 REPORT FORM 

REPORT FORM xcReport [TO PRINTER] [TO FILE xcFile] [NOCONSOLE] [scope]←↪ 

↩→[WHILE lCondition] [FOR lCondition] [PLAIN | HEADING cHeading] [NOEJECT] ←↪ 

↩→[SUMMARY] 

__ReportForm( cForm, [lToPrinter], [cToFile], [lNoConsole], [bForCondition], ←↪ 

↩→[bWhileCondition], [nNext], [nRecord], [lRest], [lPlain], [cbHeading], ←↪ 

↩→[lBeforeEject], [lSummary] ) 

366.5.36 RESTORE 

RESTORE SCREEN FROM cScreen 

restscreen( 0, 0, Maxrow(), Maxcol(), cScreen ) 

366.5.37 RESTORE FROM 

RESTORE FROM xcMemFile [ADDITIVE] 

__MRestore( cMemFileName, [lAdditive] ) 

366.5.38 RUN 

RUN xcCommandLine 

__Run( cCommand )


366.5.39 SAVE SCREEN TO 

SAVE SCREEN TO cScreen 

cScreen := savescreen( 0, 0, maxrow(), maxcol() ) 

366.5.40 SAVE TO 

SAVE TO xcMemFile [ALL [LIKE|EXCEPT skeleton]] 

_MSave( cMemFileName, [cSkeleton], [lLike] ) 

366.5.41 SEEK 

SEEK expSearch [SOFTSEEK] 

dbSeek( expSearch [, lSoftSeek] ) 

366.5.42 SELECT 

SELECT xnWorkArea | idAlias 

dbSelectArea( nWorkArea | cIdAlias ) 

366.5.43 SET 

Most of the ‘SET...’ commands are translated into the ‘SET()’ function that distinguishes different 

modes depending on a number. As this number is difficult to handle during programming 

(essentially because it is difficult to remember the meaning of it), Clipper offers the ‘SET.CH’ 

include file that helps with manifest constants. 

#define _SET_EXACT 1 

#define _SET_FIXED 2 

#define _SET_DECIMALS 3 

#define _SET_DATEFORMAT 4 

#define _SET_EPOCH 5 

#define _SET_PATH 6 

#define _SET_DEFAULT 7 

#define _SET_EXCLUSIVE 8 

#define _SET_SOFTSEEK 9 

#define _SET_UNIQUE 10 

#define _SET_DELETED 11 

#define _SET_CANCEL 12 

#define _SET_DEBUG 13 

#define _SET_TYPEAHEAD 14 

#define _SET_COLOR 15 

#define _SET_CURSOR 16 

#define _SET_CONSOLE 17 

#define _SET_ALTERNATE 18 

#define _SET_ALTFILE 19 

#define _SET_DEVICE 20 

#define _SET_EXTRA 21 

#define _SET_EXTRAFILE 22 

#define _SET_PRINTER 23


#define _SET_PRINTFILE 24 

#define _SET_MARGIN 25 

#define _SET_BELL 26 

#define _SET_CONFIRM 27 

#define _SET_ESCAPE 28 

#define _SET_INSERT 29 

#define _SET_EXIT 30 

#define _SET_INTENSITY 31 

#define _SET_SCOREBOARD 32 

#define _SET_DELIMITERS 33 

#define _SET_DELIMCHARS 34 

#define _SET_WRAP 35 

#define _SET_MESSAGE 36 

#define _SET_MCENTER 37 

#define _SET_SCROLLBREAK 38 

SET ALTERNATE TO xcFile [ADDITIVE] 

Set( _SET_ALTFILE, cFile, lAdditive ) 

SET ALTERNATE ON | OFF | xlToggle 

Set( _SET_ALTERNATE, "ON" | "OFF" | lToggle ) 

SET BELL ON | OFF | xlToggle 

Set( _SET_BELL, "ON" | "OFF" | lToggle ) 

SET COLOR | COLOUR TO (cColorString) 

SetColor( cColorString ) 

SET CONFIRM ON | OFF | xlToggle 

Set( _SET_CONFIRM, "ON" | "OFF" | lToggle ) 

SET CONSOLE ON | OFF | xlToggle 

Set( _SET_CONSOLE, "ON" | "OFF" | lToggle ) 

SET CURSOR ON | OFF | xlToggle 

SetCursor( 1 | 0 | iif( lToggle, 1, 0 ) ) 

SET DATE FORMAT [TO] cDateFormat 

Set( _SET_DATEFORMAT, cDateFormat ) 

SET DECIMALS TO 

Set( _SET_DECIMALS, 0 ) 

SET DECIMALS TO nDecimals 

Set( _SET_DECIMALS, nDecimals ) 

SET DEFAULT TO 

Set( _SET_DEFAULT, "" ) 

SET DEFAULT TO xcPathspec 

Set( _SET_DEFAULT, cPathspec ) 

SET DELETED ON | OFF | xlToggle 

Set( _SET_DELETED, "ON" | "OFF" | lToggle )


SET DELIMITERS ON | OFF | xlToggle 

Set( _SET_DELIMITERS, "ON" | "OFF" | lToggle ) 

SET DELIMITERS TO [DEFAULT] 

Set( _SET_DELIMCHARS, "::" ) 

SET DELIMITERS TO cDelimiters 

Set( _SET_DELIMCHARS, cDelimiters ) 

SET DEVICE TO SCREEN | PRINTER 

Set( _SET_DEVICE, "SCREEN" | "PRINTER" ) 

SET EPOCH TO nYear 

Set( _SET_EPOCH, nYear ) 

SET ESCAPE ON | OFF | xlToggle 

Set( _SET_ESCAPE, "ON" | "OFF" | lToggle ) 

SET EXACT ON | OFF | xlToggle 

Set( _SET_EXACT, "ON" | "OFF" | lToggle ) 

SET EXCLUSIVE ON | OFF | xlToggle 

Set( _SET_EXCLUSIVE, "ON" | "OFF" | lToggle ) 

SET FILTER TO 

dbclearfilter() 

SET FILTER TO lCondition 

dbsetfilter( bCondition, cCondition ) 

SET FIXED ON | OFF | xlToggle 

Set( _SET_FIXED, "ON" | "OFF" | lToggle ) 

SET FUNCTION nFunctionKey TO cString 

__SetFunction( nFunctionKey, cString ) 

SET INDEX TO [xcIndex [, xcIndex1... ] ] 

ordListClear() 

ordListAdd( cIndex ) 

ordListAdd( cIndex1 ) 

... 

SET INTENSITY ON | OFF | xlToggle 

Set( _SET_INTENSITY, "ON" | "OFF" | lToggle ) 

SET KEY nInkeyCode [TO] 

SetKey( nInkeyCode, NIL ) 

SET KEY nInkeyCode TO [idProcedure] 

SetKey( nInkeyCode, { |p, l, v| idProcedure(p, l, v)} ) 

SET MARGIN TO 

Set( _SET_MARGIN, 0 ) 

SET MARGIN TO [nPageOffset] 

Set( _SET_MARGIN, nPageOffset )


SET MESSAGE TO 

Set( _SET_MESSAGE, 0 ) 

Set( _SET_MCENTER, .F. ) 

SET MESSAGE TO [nRow [CENTER | CENTRE]] 

Set( _SET_MESSAGE, nRow ) 

Set( _SET_MCENTER, lCenter ) 

SET ORDER TO [nIndex] 

ordSetFocus( nIndex ) 

SET PATH TO 

Set( _SET_PATH, "" ) 

SET PATH TO [xcPathspec [, cPathspec1... ] ] 

Set( _SET_PATH, cPathspec [, cPathspec1... ] ) 

SET PRINTER ON | OFF | xlToggle 

Set( _SET_PRINTER, "ON" | "OFF" | lToggle ) 

SET PRINTER TO 

Set( _SET_PRINTFILE, "" ) 

SET PRINTER TO [xcDevice|xcFile [ADDITIVE]] 

Set( _SET_PRINTFILE, cDevice|cFile, lAdditive ) 

SET RELATION TO 

dbclearrelation() 

SET RELATION TO [expKey1 INTO xcAlias1] [, [TO] expKey2 INTO xcAlias2...] 

dbClearRel() 

dbSetRelation( cAlias1, {||expKey1}, ["expKey1"] ) 


SET RELATION TO [expKey1 INTO xcAlias1]←↪ 

↩→[, [TO] expKey2 INTO xcAlias2...] ADDITIVE 



SET SCOREBOARD ON | OFF | xlToggle 

Set( _SET_SCOREBOARD, "ON" | "OFF" | lToggle ) 

SET SOFTSEEK ON | OFF | xlToggle 

Set( _SET_SOFTSEEK, "ON" | "OFF" | lToggle ) 

SET TYPEAHEAD TO nKeyboardSise 

Set( _SET_TYPEAHEAD, nKeyboardSise ) 

SET UNIQUE ON | OFF | xlToggle 

Set( _SET_UNIQUE, "ON" | "OFF" | lToggle ) 

SET WRAP ON | OFF | xlToggle 

Set( _SET_WRAP, "ON" | "OFF" | lToggle )


366.5.44 SKIP 

SKIP [nRecords] [ALIAS idAlias|nWorkArea] 

[idAlias|nWorkArea -> ]( dbSkip([nRecords]) ) 

366.5.45 SORT 

SORT TO xcDatabase ON idField1 [/[A|D][C]] [, idField2 [/[A|D][C]] ...]←↪ 

↩→[scope] [WHILE lCondition] [FOR lCondition] 

__dbSort( cDatabase, [acFields], [bForCondition], [bWhileCondition],←↪ 


366.5.46 STORE 

STORE value TO variable 

variable := value 

366.5.47 SUM 

SUM nExp1 [, nExp2...] TO idVar1 [, idVar2...] [FOR lForCondition]←↪ 

↩→[WHILE lWhileCondition] [NEXT nNextRecords] [RECORD nRecord] [REST] [ALL] 

dbeval( {||idVar1:=idVar1+nExp1 [, idVar2:=idVar2+nExp2...] },←↪ 

↩→{||lForCondition}, {||lWhileCondition}, nNextRecords, nRecord, lRest ) 

366.5.48 TOTAL ON 

TOTAL ON expKey [FIELDS idField_list] TO xcDatabase [scope]←↪ 

↩→[WHILE lCondition] [FOR lCondition] 

__dbTotal( cDatabase, bKey, [acFields], [bForCondition], [bWhileCondition],←↪ 


366.5.49 UNLOCK 

UNLOCK 

dbUnlock() 

UNLOCK ALL 

dbUnlockAll() 

366.5.50 UPDATE FROM 

UPDATE FROM xcAlias ON expKey [RANDOM] REPLACE idField1←↪ 

↩→WITH exp [, idField2 WITH exp ...] 

__dbUpdate( cAlias, bKey, [lRandom], [bReplacement] ) 

Example:


__dbUpdate( "INVOICE", {|| LAST}, .T.,; {|| FIELD->TOTAL1 := ←↪ 

↩→INVOICE->SUM1,; FIELD->TOTAL2 := INVOICE->SUM2 } ) 

366.5.51 USE 

USE 

dbclosearea() 

USE [xcDatabase]←↪ 

↩→[INDEX xcIndex1 [, xcIndex2...] [ALIAS xcAlias] [EXCLUSIVE|SHARED] [NEW] ←↪ 

↩→[READONLY] [VIA cDriver]] 

dbUseArea( [lNewArea], [cDriver], cDatabase, [cAlias], [lShared], [lReadOnly] ) 

[dbSetIndex( cIndex1 )] 


... 

366.5.52 ZAP 

ZAP 

dbZap() 

366.6 Step 6: free yourself from STD.CH - /U 

Now that no command is used, the standard include file ‘STD.CH’ is no more necessary. Clipper 

uses ‘STD.CH’ automatically, unless specified differently. Just compile this way: 

C:>CLIPPER TEST.PRG /U 

366.7 Step 7: take control over all include files 

Clipper comes with so many include files (‘ * .CH’). To avoid confusion, a single ‘STANDARD.CH’ 

file containing all what is needed for the application may be prepared. At least, it is necessary the 

following. 

*================================================================= 

* DISPBOX() 

*================================================================= 

* Single-line box 

#define BOX_SINGLE; 

(; 

CHR(218) +; 

CHR(196) +; 

CHR(191) +; 

CHR(179) +; 

CHR(217) +; 

CHR(196) +; 

CHR(192) +; 

CHR(179); 

) 

* Double-line box


#define BOX_DOUBLE; 

(; 

CHR(201) +; 

CHR(205) +; 

CHR(187) +; 

CHR(186) +; 

CHR(188) +; 

CHR(205) +; 

CHR(200) +; 

CHR(186); 

) 

* Single-line top, double-line sides 

#define BOX_SINGLE_DOUBLE; 

(; 

CHR(214) +; 

CHR(196) +; 

CHR(183) +; 

CHR(186) +; 

CHR(189) +; 

CHR(196) +; 

CHR(211) +; 

CHR(186); 

) 

* Double-line top, single-line sides 

#define BOX_DOUBLE_SINGLE; 

(; 

CHR(213) +; 

CHR(205) +; 

CHR(184) +; 

CHR(179) +; 

CHR(190) +; 

CHR(205) +; 

CHR(212) +; 

CHR(179); 

) 

*================================================================= 

* ERRORS 

*================================================================= 

* Severity levels (e:severity) 

#define ERROR_SEVERITY_WHOCARES 0 

#define ERROR_SEVERITY_WARNING 1 

#define ERROR_SEVERITY_ERROR 2 

#define ERROR_SEVERITY_CATASTROPHIC 3 

* Generic error codes (e:genCode) 

#define ERROR_GENERIC_ARG 1 

#define ERROR_GENERIC_BOUND 2 

#define ERROR_GENERIC_STROVERFLOW 3 

#define ERROR_GENERIC_NUMOVERFLOW 4 

#define ERROR_GENERIC_ZERODIV 5 

#define ERROR_GENERIC_NUMERR 6 

#define ERROR_GENERIC_SYNTAX 7 

#define ERROR_GENERIC_COMPLEXITY 8 

#define ERROR_GENERIC_MEM 11 

#define ERROR_GENERIC_NOFUNC 12 

#define ERROR_GENERIC_NOMETHOD 13 

#define ERROR_GENERIC_NOVAR 14 

#define ERROR_GENERIC_NOALIAS 15


#define ERROR_GENERIC_NOVARMETHOD 16 

#define ERROR_GENERIC_BADALIAS 17 

#define ERROR_GENERIC_DUPALIAS 18 

#define ERROR_GENERIC_CREATE 20 

#define ERROR_GENERIC_OPEN 21 

#define ERROR_GENERIC_CLOSE 22 

#define ERROR_GENERIC_READ 23 

#define ERROR_GENERIC_WRITE 24 

#define ERROR_GENERIC_PRINT 25 

#define ERROR_GENERIC_UNSUPPORTED 30 

#define ERROR_GENERIC_LIMIT 31 

#define ERROR_GENERIC_CORRUPTION 32 

#define ERROR_GENERIC_DATATYPE 33 

#define ERROR_GENERIC_DATAWIDTH 34 

#define ERROR_GENERIC_NOTABLE 35 

#define ERROR_GENERIC_NOORDER 36 

#define ERROR_GENERIC_SHARED 37 

#define ERROR_GENERIC_UNLOCKED 38 

#define ERROR_GENERIC_READONLY 39 

#define ERROR_GENERIC_APPENDLOCK 40 

#define ERROR_GENERIC_LOCK 41 

*================================================================= 

* INKEY() 

*================================================================= 

#define K_UP 5 // Up arrow, Ctrl-E 

#define K_DOWN 24 // Down arrow, Ctrl-X 

#define K_LEFT 19 // Left arrow, Ctrl-S 

#define K_RIGHT 4 // Right arrow, Ctrl-D 

#define K_HOME 1 // Home, Ctrl-A 

#define K_END 6 // End, Ctrl-F 

#define K_PGUP 18 // PgUp, Ctrl-R 

#define K_PGDN 3 // PgDn, Ctrl-C 

#define K_CTRL_UP 397 // * Ctrl-Up arrow 

#define K_CTRL_DOWN 401 // * Ctrl-Down arrow 

#define K_CTRL_LEFT 26 // Ctrl-Left arrow, Ctrl-Z 

#define K_CTRL_RIGHT 2 // Ctrl-Right arrow, Ctrl-B 

#define K_CTRL_HOME 29 // Ctrl-Home, Ctrl- 

#define K_CTRL_END 23 // Ctrl-End, Ctrl-W 

#define K_CTRL_PGUP 31 // Ctrl-PgUp, Ctrl-Hyphen 

#define K_CTRL_PGDN 30 // Ctrl-PgDn, Ctrl-^ 

#define K_ALT_UP 408 // * Alt-Up arrow 

#define K_ALT_DOWN 416 // * Alt-Down arrow 

#define K_ALT_LEFT 411 // * Alt-Left arrow 

#define K_ALT_RIGHT 413 // * Alt-Right arrow 

#define K_ALT_HOME 407 // * Alt-Home 

#define K_ALT_END 415 // * Alt-End 

#define K_ALT_PGUP 409 // * Alt-PgUp 

#define K_ALT_PGDN 417 // * Alt-PgDn 

#define K_ENTER 13 // Enter, Ctrl-M 

#define K_RETURN 13 // Return, Ctrl-M 

#define K_SPACE 32 // Space bar 

#define K_ESC 27 // Esc, Ctrl- 

#define K_CTRL_ENTER 10 // Ctrl-Enter 

#define K_CTRL_RETURN 10 // Ctrl-Return


#define K_CTRL_RET 10 // Ctrl-Return (Compat.) 

#define K_CTRL_PRTSCR 379 // * Ctrl-Print Screen 

#define K_CTRL_QUESTION 309 // Ctrl-? 

#define K_ALT_ENTER 284 // * Alt-Enter 

#define K_ALT_RETURN 284 // * Alt-Return 

#define K_ALT_EQUALS 387 // * Alt-Equals 

#define K_ALT_ESC 257 // * Alt-Esc 

#define KP_ALT_ENTER 422 // * Keypad Alt-Enter 

#define KP_CTRL_5 399 // * Keypad Ctrl-5 

#define KP_CTRL_SLASH 405 // * Keypad Ctrl-/ 

#define KP_CTRL_ASTERISK 406 // * Keypad Ctrl-* 

#define KP_CTRL_MINUS 398 // * Keypad Ctrl-- 

#define KP_CTRL_PLUS 400 // * Keypad Ctrl-+ 

#define KP_ALT_5 5 // * Keypad Alt-5 

#define KP_ALT_SLASH 420 // * Keypad Alt-/ 

#define KP_ALT_ASTERISK 311 // * Keypad Alt-* 

#define KP_ALT_MINUS 330 // * Keypad Alt-- 

#define KP_ALT_PLUS 334 // * Keypad Alt-+ 

#define K_INS 22 // Ins, Ctrl-V 

#define K_DEL 7 // Del, Ctrl-G 

#define K_BS 8 // Backspace, Ctrl-H 

#define K_TAB 9 // Tab, Ctrl-I 

#define K_SH_TAB 271 // Shift-Tab 

#define K_CTRL_INS 402 // * Ctrl-Ins 

#define K_CTRL_DEL 403 // * Ctrl-Del 

#define K_CTRL_BS 127 // Ctrl-Backspace 

#define K_CTRL_TAB 404 // * Ctrl-Tab 

#define K_ALT_INS 418 // * Alt-Ins 

#define K_ALT_DEL 419 // * Alt-Del 

#define K_ALT_BS 270 // * Alt-Backspace 

#define K_ALT_TAB 421 // * Alt-Tab 

#define K_CTRL_A 1 // Ctrl-A, Home 

#define K_CTRL_B 2 // Ctrl-B, Ctrl-Right arrow 

#define K_CTRL_C 3 // Ctrl-C, PgDn, Ctrl-ScrollLock 

#define K_CTRL_D 4 // Ctrl-D, Right arrow 

#define K_CTRL_E 5 // Ctrl-E, Up arrow 

#define K_CTRL_F 6 // Ctrl-F, End 

#define K_CTRL_G 7 // Ctrl-G, Del 

#define K_CTRL_H 8 // Ctrl-H, Backspace 

#define K_CTRL_I 9 // Ctrl-I, Tab 

#define K_CTRL_J 10 // Ctrl-J 

#define K_CTRL_K 11 // Ctrl-K 

#define K_CTRL_L 12 // Ctrl-L 

#define K_CTRL_M 13 // Ctrl-M, Return 

#define K_CTRL_N 14 // Ctrl-N 

#define K_CTRL_O 15 // Ctrl-O 

#define K_CTRL_P 16 // Ctrl-P 

#define K_CTRL_Q 17 // Ctrl-Q 

#define K_CTRL_R 18 // Ctrl-R, PgUp 

#define K_CTRL_S 19 // Ctrl-S, Left arrow 

#define K_CTRL_T 20 // Ctrl-T 

#define K_CTRL_U 21 // Ctrl-U 

#define K_CTRL_V 22 // Ctrl-V, Ins 

#define K_CTRL_W 23 // Ctrl-W, Ctrl-End 

#define K_CTRL_X 24 // Ctrl-X, Down arrow 

#define K_CTRL_Y 25 // Ctrl-Y


#define K_CTRL_Z 26 // Ctrl-Z, Ctrl-Left arrow 

#define K_ALT_A 286 // Alt-A 

#define K_ALT_B 304 // Alt-B 

#define K_ALT_C 302 // Alt-C 

#define K_ALT_D 288 // Alt-D 

#define K_ALT_E 274 // Alt-E 

#define K_ALT_F 289 // Alt-F 

#define K_ALT_G 290 // Alt-G 

#define K_ALT_H 291 // Alt-H 

#define K_ALT_I 279 // Alt-I 

#define K_ALT_J 292 // Alt-J 

#define K_ALT_K 293 // Alt-K 

#define K_ALT_L 294 // Alt-L 

#define K_ALT_M 306 // Alt-M 

#define K_ALT_N 305 // Alt-N 

#define K_ALT_O 280 // Alt-O 

#define K_ALT_P 281 // Alt-P 

#define K_ALT_Q 272 // Alt-Q 

#define K_ALT_R 275 // Alt-R 

#define K_ALT_S 287 // Alt-S 

#define K_ALT_T 276 // Alt-T 

#define K_ALT_U 278 // Alt-U 

#define K_ALT_V 303 // Alt-V 

#define K_ALT_W 273 // Alt-W 

#define K_ALT_X 301 // Alt-X 

#define K_ALT_Y 277 // Alt-Y 

#define K_ALT_Z 300 // Alt-Z 

#define K_ALT_1 376 // Alt-1 










#define K_F1 28 // F1, Ctrl-Backslash 

#define K_F2 -1 // F2 








#define K_F10 -9 // F10 

#define K_F11 -40 // * F11 

#define K_F12 -41 // * F12 

#define K_CTRL_F1 -20 // Ctrl-F1 










#define K_CTRL_F11 -44 // * Ctrl-F11 

#define K_CTRL_F12 -45 // * Ctrl-F12


#define K_ALT_F1 -30 // Alt-F1 










#define K_ALT_F11 -46 // * Alt-F11 

#define K_ALT_F12 -47 // * Alt-F12 

#define K_SH_F1 -10 // Shift-F1 










#define K_SH_F11 -42 // * Shift-F11 

#define K_SH_F12 -43 // * Shift-F12 

*================================================================= 

* MEMOEDIT() 

*================================================================= 

* User function entry modes 

#define MEMOEDIT_IDLE 0 // idle, all keys processed 

#define MEMOEDIT_UNKEY 1 // unknown key, memo unaltered 

#define MEMOEDIT_UNKEYX 2 // unknown key, memo altered 

#define MEMOEDIT_INIT 3 // initialization mode 

* User function return codes 

#define MEMOEDIT_DEFAULT 0 // perform default action 

#define MEMOEDIT_IGNORE 32 // ignore unknown key 

#define MEMOEDIT_DATA 33 // treat unknown key as data 

#define MEMOEDIT_TOGGLEWRAP 34 // toggle word-wrap mode 

#define MEMOEDIT_TOGGLESCROLL 35 // toggle scrolling mode 

#define MEMOEDIT_WORDRIGHT 100 // perform word-right operation 

#define MEMOEDIT_BOTTOMRIGHT 101 // perform bottom-right operation 

*================================================================= 

* SET() 

*================================================================= 

#define _SET_EXACT 1 

#define _SET_FIXED 2 

#define _SET_DECIMALS 3 

#define _SET_DATEFORMAT 4 

#define _SET_EPOCH 5 

#define _SET_PATH 6 

#define _SET_DEFAULT 7 

#define _SET_EXCLUSIVE 8 

#define _SET_SOFTSEEK 9 

#define _SET_UNIQUE 10


#define _SET_DELETED 11 

#define _SET_CANCEL 12 

#define _SET_DEBUG 13 

#define _SET_TYPEAHEAD 14 

#define _SET_COLOR 15 

#define _SET_CURSOR 16 

#define _SET_CONSOLE 17 

#define _SET_ALTERNATE 18 

#define _SET_ALTFILE 19 

#define _SET_DEVICE 20 

#define _SET_EXTRA 21 

#define _SET_EXTRAFILE 22 

#define _SET_PRINTER 23 

#define _SET_PRINTFILE 24 

#define _SET_MARGIN 25 

#define _SET_BELL 26 

#define _SET_CONFIRM 27 

#define _SET_ESCAPE 28 

#define _SET_INSERT 29 

#define _SET_EXIT 30 

#define _SET_INTENSITY 31 

#define _SET_SCOREBOARD 32 

#define _SET_DELIMITERS 33 

#define _SET_DELIMCHARS 34 

#define _SET_WRAP 35 

#define _SET_MESSAGE 36 

#define _SET_MCENTER 37 

#define _SET_SCROLLBREAK 38 

*================================================================= 

* SETCURSOR() 

*================================================================= 

#define SETCURSOR_NONE 0 // No cursor 

#define SETCURSOR_NORMAL 1 // Normal cursor (underline) 

#define SETCURSOR_INSERT 2 // Insert cursor (lower half block) 

#define SETCURSOR_SPECIAL1 3 // Special cursor (full block) 

#define SETCURSOR_SPECIAL2 4 // Special cursor (upper half block) 

*================================================================= 

* RDD REQUESTs 

*================================================================= 

external dbfndx 

external dbfntx // default 


nanoBase 1997 

A free xBase for Dos. 

Chapter 367 


7737/nanobase.html’, in 1997. Now it is incorporated inside the Italian document 

‘‘Appunti di informatica libera’’, and might be reached at the URI . 


SiliconValley/7737/nanobase.html’. Adesso viene incorporato nel documento «Appunti 

di informatica libera» e può essere raggiunto attraverso l’URI . 

367.1 What is it 

nanoBase 1 is a Dos program that works essentially as: 

• a dot command line xBase, 

• a menu driven xBase, 

• a xBase program interpreter. 

nanoBase 1997 is compiled in two versions: a small one to be used with old computers (i86 with 

640 Kibyte RAM), and a second one to be used with better computers, at least i286 (or better) 

with 2 Mibyte RAM. 

367.2 The dot command line 

Figure 367.1. The dot line. 

The dot command line is the first face of nanoBase, the one that appears starting the program 

normally. It recalls the dot line command of the old xBases. 

Please note that nanoBase recognise only expressions (that is: no commands). 

1 nanoBase GNU GPL 

160

nanoBase 1997 161 

367.3 The menu 

Figure 367.2. The file menu. 

Pressing [ F10 ] the nanoBase menu appears. 

From this menu the operations are easier than writing all commands on a prompt line, but it is 

always possible to come back to the dot line to do an operation not available from the menu. 

367.4 The macro recording, compiling and execution 

Figure 367.3. The macro menu. 

nanoBase is able to record some actions made with the menu and all what is correctly typed from 

the dot prompt. This may be the begin for a little program (called macro inside nanoBase) that 

can be executed as it is (ASCII), or compiled into another format, faster to execute. 

Macros for nanoBase are made with a reduced set of the Clipper syntax. The statements recognised 

from nanoBase are: 

PROCEDURE procedure_name 

statements... 

[RETURN] 

statements... 

ENDPROCEDURE


DO PROCEDURE procedure_name 

BEGIN SEQUENCE 

statements... 

[BREAK] 

statements... 

END 

DO CASE 

CASE lCondition1 

statements... 

[CASE lCondition2] 

statements... 

[OTHERWISE] 

statements... 

END 

WHILE lCondition 

statements... 

[EXIT] 

statements... 

[LOOP] 

statements... 

END 

IF lCondition1 

statements... 

[ELSE] 

statements... 

END 

• the ‘FOR’ loop is not available (too difficult to implement), 

• there may be no user defined functions (code blocks may be created instead), 

• procedure calls cannot transfer variables, 

• there are only public (global) variables. 

Beside these limitations, there are many added functions to the standard language that make the 

programming easier. 

All you need is inside ‘NB.EXE’: 

• the utility to handle manually the data, 

• the macro compiler, 

• the macro executor.


367.5 The report system 

Figure 367.4. The report menu. 

nanoBase can handle label (‘.LBL’) and form (‘.FRM’) files in the dBaseIII format. Labels and 

forms may be created and edited inside nanoBase. Beside these old report system there is another 

way to make a little bit complicated reports without making a complex macro: it is called RPT. 

A RPT file is a ASCII file with text mixed with code. The text may contain variables (usually a 

field or an expression containing fields). 

To make a complex report some work is needed, but surely less than the time needed to make a 

report program. 

The main purpose of it was to be able to print text with variables (typically names and addresses) 

for every record of a particular ‘.DBF’ file. Now the RPT system makes something more. 

367.6 The integrated text editor 

Figure 367.5. The integrated text editor. 

nanoBase contains an integrated text editor not particularly good, but very usefull for RPT files 

(as the expression insertion is very easy with the use of the [ F2 ] key) and whenever there isn’t 

any other editor there.


367.7 The internal documentation 

Figure 367.6. The internal documentation. 

nanoBase’s documentation si translated also inside the HTF format: ‘NB.HLP’. Pressing [ F1 ], 

normally, a contextual piece of the manual appears. 

Some standard functions have its own internal help, contained inside the ‘.EXE’ file. This was 

made to help programming with nanoBase. 

367.8 Download it 

Here is the 1997 edition of nanoBase. 

• EXE for small computers. 

 

 

• EXE for i286 with more than 2 Mibyte. 

 

 

• Runtime for small computers. 

 

 

• Documentation in many different formats. 

 

 

• Macro programming examples. 

 

 

• Source for version 96.06.16, without mouse support (1996). 

 


• Source for version 1997. 

 

 

367.9 Bugs and known problems 

Here is the list of known bugs and problems. 

• Comparison with floating point numbers may fail. It is better to convert numbers into string 

before comparing them. 

• Macros may be contained inside ASCII files or a ‘‘compiled’’ ‘.DBF’ file. In the second 

case, when nanoBase executes the macro, a work area (the last available one) is used, so it 

should not be closed or the macro execution will be stopped. A ‘dbcloseall()’ will stop 

execution of the macro. In substitution of ‘dbcloseall()’, ‘DBCLOSE()’ should be used. 

• To simplify the macro interpretation, lines such as this: 

qqout( "You can’t do that // you can’t do that!" ) 

will generate an error as the interpreter will read only: 

qqout( "You can’t do that 

• nanoBase works good also if you have a screen configuration that permits you to show more 

than the usual 80 columns and 25 lines, but the library used to handle the mouse is not able 

to work outside the 80×25 area. 


nanoBase 1997 user manual 

Chapter 368 

This is the documentation of nanoBase 1997, with minor modifications, that appeared originally 

at ‘http://www.geocities.com/SiliconValley/7737/nb.htm’. Now it is incorporated 

inside the Italian document ‘‘Appunti di informatica libera’’, and might be reached at 

the URI . 

Questo è il manuale di nanoBase 1997, modificato leggermente, che è apparso inizialmente 

presso ‘http://www.geocities.com/SiliconValley/7737/nb.htm’. Adesso 

viene incorporato nel documento «Appunti di informatica libera» e può essere raggiunto attraverso 

l’URI . 

368.1 Dos xBase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 

368.2 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 

368.3 How to use nB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 

368.4 Status line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 

368.5 The dot line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 

368.6 The menu system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 

368.7 The text editor DOC() . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

368.8 The help text file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

368.9 Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 

368.10 Data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 

368.11 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200 

368.12 Delimiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 

368.13 Code blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 

368.14 Standard functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 

368.15 nB functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 

368.16 Normal command substitution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 

368.17 nB command substitution functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305 

368.18 RPT: the nB print function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 

368.19 How can I... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 

368.20 The source files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 

nB (‘‘nano Base’’: ‘‘n’’ = ‘‘nano’’ = 10**(-9) = ‘‘very little’’) is a little Dos xBase written in 

Clipper 5.2 that can help to access ‘.DBF’ file created with different standards. 

nB is: 

• a dot command interpreter, 

166

nanoBase 1997 user manual 167 

• a menu driven xBase, 

• a xBase program interpreter. 

368.1 Dos xBase 

This section is a brief description of the functionality of a typical Dos xBase. 

The first purpose of a xBase program is to handle data inside a ‘.DBF’ file. These files may be 

indexed with the help of index files and more ‘.DBF’ files may be linked with a relation to obtain 

something like a relational database. 

368.1.1 .DBF files 

‘.DBF’ files are files organised in a table structure: 

.--------------------------. 

| field1 | field2 | field3 | record1 

|--------|--------|--------| 

| | | | record2 

|--------|--------|--------| 

| | | | record3 

|--------|--------|--------| 

| | | | record4 

|--------|--------|--------| 

| | | | record5 

|--------|--------|--------| 

| | | | record6 

‘--------------------------’ 

The lines of this table are records and the columns are fields. Records are numbered starting from 

the first that is number 1. 

Columns are defined as fields and fields are distinguished by name and these names are saved 

inside the ‘.DBF’ file. 

Every field (column) can contain only one specified kind of data with a specified dimension: 

• ‘C’, character, originally the maximum dimension was 254 characters, minimum is 1; 

• ‘N’, numeric, a numeric field that can contain also sign and decimal values; 

• ‘D’, date, a field dedicated to date information; 

• ‘L’, logic, a filed that may contain only ‘T’ for True or ‘F’ for False used as a boolean 

variable; 

• ‘M’, memo, a character field with no predefined dimension, not allocated directly inside the 

‘.DBF’, but inside a ‘.DBT’ file, automatically linked. 

No other field type is available for a typical xBase ‘.DBF’ file. 

To access the data contained inside a ‘.DBF’ file the following list of action may be followed: 

• Open a ‘.DBF’ file inside the current area, where these areas are something like file handlers. 

• After the ‘.DBF’ file is opened, it referenced only by the alias name that usually correspond 

to the original filename without extention.


• Move the record pointer to the desired location. 

• Lock the current record to avoid access from other users. 

• Do some editing with the data contained inside the current record using the field names like 

they were variables. 

• Release the lock. 

• Move the record pointer to another desired location. 


• ... 

• Close the alias. 

Before you go further, you have to understand that: 

• A ‘.DBF’ file is opened using a free WORK AREA that may be associated to the concept 

of the file handler. 

• The ‘.DBF’ file is opened with a alias name that permit to open the same ‘.DBF’ file more 

times when using different alias names. 

• After the ‘.DBF’ file is opened, we don’t speak any more of file, but alias. 

• If the work area "n" is used from the alias "myAlias", speaking of work area "n" or of alias 

"myAlias" is the same thing. 

368.1.2 Index files 

‘.DBF’ files are organised with record number, that is, you can reach a specific record and not a 

specific information unless that you scan record by record. 

To obtain to "see" a ‘.DBF’ file somehow logically ordered (when physically it is not), index files 

are used. 

A index file, also called INDEX BAG, is a file that contains one or more indexes 

Indexes are rules by which a ‘.DBF’ file may be seen ordered. 

A typical index file may contain only one index. 

A index file may have the following extention: 

• ‘.NDX’, single index, dBase III and dBase III plus; 

• ‘.NTX’, single index, Clipper; 

• ‘.MBX’, multiple index, dBase IV; 

• ‘.CDX’, multiple index, FoxPro. 

Every index file may be used only in association with the ‘.DBF’ for what it was made. The 

problem is that normally there is no way to avoid errors when the user try to associate the right 

‘.DBF’ file with the wrong index.


To access the data contained inside a ‘.DBF’ file the following list of action may be followed: 

• Open a ‘.DBF’ file. 

• Open a index file. 

• Select a particular order. 

• Search for a key or move the record pointer on a different way. 




• Release the lock. 



• ... 

• Close the alias. 

Before you go further, you have to understand that: 

• As orders are contained inside a INDEX BAG file physically distinguished form the ‘.DBF’ 

file, it may happen that a ‘.DBF’ file is wrongly opened and edited without the index. In 

this case, the INDEX BAG is not updated and when the INDEX BAG will be opened, the 

records contained inside the ‘.DBF’ file may not correspond. 

• For the same reason, an improper program termination may result in an incomplete data 

update. That is: ‘.DBF’ file may be all right, INDEX BAG not. 

• This is why xBase programs are "weak" relational databases or they are not relational 

databases at all. 

• When troubles occurs, indexes must be rebuild. 

368.1.3 Relations 

Many ‘.DBF’ files with indexes may be opened simultaneously. Data contained inside more 

‘.DBF’ files may be somehow connected together. See the example.


.----------------------------------------. 

| Date | Time IN | Time OUT | Employee # | 

|------|---------|-----------------------| 

| xxxx | xxxxxxx | xxxxxxxx | 01 | -------->. 

|------|---------|----------|------------| | 

| yyyy | yyyyyyy | yyyyyyyy | 02 | | 

|------|---------|----------|------------| | 

| zzzz | zzzzzzz | zzzzzzzz | 01 | -------->| 

‘----------------------------------------’ | 

[...] | 

| 

.| 01 | aaaaaaa | aaaaaaa |.....| 

|------------|---------|---------|-----| 

| 02 | bbbbbbb | bbbbbbb |.....| 

|------------|---------|---------|-----| 

| 03 | ccccccc | ccccccc |.....| 

‘--------------------------------------’ 

The first ‘.DBF’ file contains some data that refers to an Employee number that may appear 

repeated on more records. 

Employee informations are stored inside another ‘.DBF’ file that contains only one record for 

every employee. 

Establishing a relation from the first ‘.DBF’ file to the second, moving the record pointer of the 

first ‘.DBF’ file, that is the first alias, the record pointer of the second, the child alias, is moved 

automatically to the record containing the right data. 

The relation is an expression that should result in a number if the child alias is opened without 

index, or in a valid index key if the child alias is opened with an index. 

To relate two ‘.DBF’ files the following list of action may be followed: 

• Open the first ‘.DBF’ file. 

• Open a index file for the first alias. 


• Open the second ‘.DBF’ file. 

• Open a index file for the second alias. 


• Select the first alias. 

• Define a relation form the first alias and the second alias: the child alias. 

• Search for a key or move the record pointer of the first alias (don’t care about the Child 

alias). 


• If data contained inside the Child alias should be edited (usually it doesn’t happen), lock 

the current record of the Child alias.




• Release the lock (also with the Child alias if a lock was made). 



• [...] 

• Release the relation. 

• Close the Child alias. 

• Close the first alias. 

As may be seen, relations are not saved inside files, but are obtained with lines of code. 

368.2 Composition 

nB is composed from the following files, where xx is the the version code. 

NBASExx1.ZIP EXEs for small PCs 

NBASExx2.ZIP Runtime EXEs for small PCs 

NBASExx3.ZIP EXEs for i286 with 2M+ 

NBASExx4.ZIP DOCs 

NBASExx5.ZIP EXAMPLEs 

NBASExx6.ZIP SRCs for version 96.06.16 

NBASExx7.ZIP SRCs for the current version 

Every archive file contains: 

‘COPYING.TXT’ GNU General Public License version 2 in Dos text format. 

‘README.TXT’ the readme file. 

‘FILE_ID.DIZ’ definition. 

The file ‘NBASExx1.ZIP’ contains also the following files. 

‘NB.EXE’ 

the executable program for DBFNTX and DBFNDX files, 

linked with RTLINK. 

‘NB.HLP’ this manual in "Help Text File" format. 

The file NBASExx2.ZIP contains also the following files. 

‘NB.EXE’ 


the run-time to execute macro programs for DBFNTX and 

DBFNDX files handling, linked with RTLINK. 

‘NB.EXE’ 

the executable program for DBFCDX, DBFMDX, DBFNDX 

and DBFNTX files, linked with EXOSPACE. 

‘NB.HLP’ the user manual in "Help Text File" format.



‘NB.PRN’ the user manual in printed text format. 

‘NB.RTF’ the user manual in RTF format. 

‘NB.TXT’ the user manual in ASCII text format. 

‘NB.HTM’ the user manual in HTML format. 


‘_ADDRESS.DBF’ an example database file. 

‘_ADDRESS.NTX’ index file associated to ‘_ADDRESS.DBF’. 

‘_ADDRESS.LBL’ 

a label form file used to print data contained inside 

‘_ADDRESS.DBF’ . 

‘_ADDRESS.FRM’ 

a report form file used to print data contained inside 


‘_ADDRESS.RPT’ 

a RPT text file 


used to print data contained inside 

‘_MAINMNU.&’ 

a macro program source example of a menu that executes 

some others macro programs. This example is made to 

demonstrate how nB can execute directly a source code without 

compiling it. This example is made only to taste it: it is 

very slow and only a speedy machine can give the idea of it. 

a macro program source example of a menu that executes 

‘0MAINMNU.&’ 

some others macro programs. It is the same as ‘_MAINMNU.&’ 

but it is made to start the execution of the compiled macros. 

‘0MAINMNU.NB’ compiled macro program ‘0MAINMNU.&’ 

‘0MAINMNU.BAT’ 

a batch file to 

‘0MAINMNU.NB’ 

show how to run the execution of 

‘1ADDRESS.&’ 

a macro program source example for handling a ‘.DBF’ file 

containing addresses in various ways. 

‘1ADDRESS.NB’ compiled macro ‘1ADDRESS.&’ . 



containing addresses in various ways: a little bit more complicated 

than 1ADDRESS.&. 





than ‘2ADDRESS.&’ . 

‘3ADDRESS.NB’ compiled macro ‘3ADDRESS.&’. 




than ‘3ADDRESS.&’ . 


‘ABIORITM.&’ 

a macro program source example for calculating the personal 

bio wave. 

‘ABIORITM.NB’ compiled macro ‘ABIORITM.&’ . 

‘_STUDENT.DBF’ a ‘.DBF’ file used inside the BSTUDENT macro example. 

‘_STUDENT.NTX’ index file used for ‘_STUDENT.DBF’ . 

‘_STUDSTD.DBF’ a ‘.DBF’ file used inside the BSTUDENT macro example. 

‘_STUDENT.RPT’ 


‘_STUDENT.DBF’ . 


‘_STUDSTD.RPT’ 


‘_STUDSTD.DBF’ . 


‘BSTUDENT.&’ 

a macro program source example for students evaluation: a 

description about students is obtained linking other standard 

descriptions. 

‘BSTUDENT.NB’ compiled macro ‘BSTUDENT.&’ .


‘CBATMAKE.&’ 

a macro program source example to generate a batch file to be 

used to back up an entire hard disk. 

‘CBATMAKE.NB’ compiled macro ‘CBATMAKE.&’ . 

‘BROWSE.&’ 

‘BROWSE.NB’ compiled macro ‘BROWSE.&’ . 

a macro program source example to start an automatic 

browse. 

‘BROWSE.BAT’ 

batch file to start a ‘.DBF’ browse with the BROWSE macro 

program. 

‘MENU.&’ a macro program source example for a Dos menu. 

‘MENU.NB’ compiled macro ‘MENU.&’ . 

‘MENU.BAT’ batch file to use the MENU macro. 

The file ‘NBASExx6.ZIP’ contains also the following files: source code for the version 96.06.16. 

‘NB.PRG’ the main source file for version 96.06.16. 

‘NB_REQ.PRG’ the source file containing links to all the standard functions. 

‘NB.LNK’ link file for compilation. 

‘NB_NRMAL.RMK’ rmake file to compile with RTLink. 

‘NB_EXOSP.RMK’ rmake file to compile with Exospace. 

‘NB_RUNTI.RMK’ 

rmake file to compile with RTLink defining RUNTIME to obtain 

a small nB runtime version. 

‘MACRO.LNK’ link file to compile and link a macro. 

‘MACRO.RMK’ rmake file to compile and link a macro. 

The file ‘NBASExx7.ZIP’ contains also the following files: source code for the current version. 

‘NB.PRG’ the main source file. 

‘REQUEST.PRG’ the source file containing links to all the Clipper functions. 

‘STANDARD.PRG’ the source file for standard functions. 

‘EXTRA.PRG’ the source file for other standard functions. 

‘STANDARD.CH’ 

general include file that substitutes all include file normally 

used for normal Clipper compilations. 

‘NB.CH’ include file specific for nB. 

‘NB.LNK’ link file for compilation. 

‘NB_RUNTI.LNK’ link file for runtime compilation. 

‘NB_NRMAL.RMK’ rmake file to compile with RTLink. 

‘NB_EXOSP.RMK’ rmake file to compile with Exospace. 

‘NB_RUNTI.RMK’ 

rmake file to compile with RTLink defining RUNTIME to obtain 

a small nB runtime version. 

‘MACRO.CH’ include file to compile and link a macro. 

‘MACRO.LNK’ link file to compile and link a macro. 

‘MACRO.RMK’ rmake file to compile and link a macro. 

‘CLIPMOUSE.ZIP’ 

368.3 How to use nB 

nB normal syntax is: 

nB [nB_parameters] [macro_filename] [macro_parameters] 

a simple free library for mouse support under Clipper (c) 1992 

Martin Brousseau. 

To run nB, just type the word "NB" and press [ Enter ] to execute. It will run in command mode, 

this means that it will look like an old xBASE command prompt.


To run the program as a macro interpreter, type the word NB followed from the macro file name 

with extention (no default extention is supposed). If parameters are given, after the macro file 

name, these will be available inside the public variables: c_Par1, c_Par2, ..., c_Par9. c_Par0 will 

contain the macro file name (see the macro file BROWSE.&). nB will terminate execution when 

the macro terminates. 

These parameters are available for nB: 

-c 

-w 

-? 

nB macro "compilation" syntax is: 

nB -m source_macro_filename [destination_macro_filename] 

Suppress the copyright notice. It is usefull when using nB for 

macro interpretation. 

Suppress the "Wait-Wheel" if not desired. It is the "Wheel" 

that appears at top-left when a macro is interpreted or other 

long elaborations are executed. 

Shows a short help. 

With the -m parameter, nB "compiles" the ASCII source_macro_filename into 

destination_macro_filename. 

368.4 Status line 

nB shows a "status line" at the top of the screen when the nB command prompt or the menu 

system is active. It shows some important informations. 

| |DBFNTX ||*| 1|ADDRESS | 1/ 4|ADDRESS.NTX | 

| | | | | | | 

| | | | | | | 

| | | | | | Last record (7). 

| | | | | | 

| | | | | Record pointer position (6). 

| | | | | 

| | | | Active alias (5). 

| | | | 

| | | Current Work Area (4) 

| | | 

| | Deleted record appearance (3) 

| | 

| Actual default database driver (2). 

| 

Macro recorder indicator (1). 

| 1/ 4|ADDRESS.NTX | 1|ADDRESS | 

| | | 

| | | 

| | Order Tag Name (10) 

| | 

| Order number (9) 

| 

Order Bag name (8) 

(1) This is the place for the macro recorder indicator. The symbol used is "&". Blank means that 

the macro recorder is OFF; & blinking means that the macro recorder is ON; & fixed means that 

the macro recorder is PAUSED. 

(2) The name of the default database driver. It is not necessarily the database driver for the active 

alias; it is only the database driver that will be used for the next open/create operation.


(3) An asterisk (*) at this position indicates that SET DELETED is OFF. This means that deleted 

records are not filtered. When a BLANK is in this place, SET DELETED is ON, so that deleted 

records are filtered. 

(4) The active work area number, that is, the area of the active alias. 

(5) The active alias name. Note that the alias name is not necessarily equal to the ‘.DBF’ file 

name. 

(6) The actual record pointer position for the active alias. 

(7) The number of records contained inside the active alias. 

(8) The Order Bag name; that is the index file name. 

(9) The order number. 

(10) The order tag (name). When DBFNTX database driver is used, it correspond to the Order 

Bag name. 

368.5 The dot line 

Starting nB without parameters, the dot line appears. This is the place where commands in form 

of functions may be written and executed like a old xBase. 

The functions written inside the command line that don’t result in an error, are saved inside a 

history list. This history list may be recalled with [ F2 ] and then the selected history line may be 

reused (eventually edited). Key [ up ]/[ down ] may be used to scroll inside the history list without 

showing the all list with [ F2 ]. 

[ Enter ] is used to tell nB to execute the written function. 

As the dot line is not an easy way to use such a program, a menu is available pressing [ F10 ] or 

[ Alt+M ]. The [ F10 ] key starts the ASSIST() menu. This menu may be started also entering the 

name of the function: "ASSIST()". 

nB includes a simple built-in text editor: DOC(). It may be started from the dot line entering 

"DOT()". No special key is dedicated to start this function. 

368.6 The menu system 

The nB menu system appears differently depending on the place where it is "called". When 

available, the menu system appears pressing [ Alt+M ] or [ F10 ]. 

The Menu system is organised into horizontal menu, vertical menu, and pop-up menu. 

The horizontal menu contains selectable items organised horizontally: 

One Two Three Four Five 

The cursor may be moved on a different position using arrow keys [ Left ]/[ Right ]; [ Esc ] terminates 

the menu; [ Enter ] opens a vertical menu. 

The vertical menu contains selectable items organised vertically: 


.----------. 

|First | 

|Second | 

|Third | 

‘----------’


The cursor may be moved on a different position using arrow keys [ Up ]/[ Down ]; the arrow keys 

[ Left ]/[ Right ] change the vertical menu; [ Esc ] closes the vertical the menu; [ Enter ] starts the selected 

menu function. 

The vertical menu contains selectable items organised vertically: 


.----------. 

|First | 

|Second >|--------------. 

|Third |Sub function 1| 

‘----------|Sub function 2| 

‘--------------’ 

The cursor may be moved on a different position using arrow keys [ Up ]/[ Down ]; [ Esc ] closes the 

pop-up the menu; [ Enter ] starts the selected menu function. 

The following sections describe the menu system. 

368.6.1 Menu File 

The menu File contains important function on ‘.DBF’ file, indexes, relations and Replaceable 

database drivers. 

For database files are considered two aspects: the physical aspect, and the logical alias. When a 

‘.DBF’ file is opened, it becomes a alias. 

Indexes are considered as index files and index orders. 

It follows a brief menu function description. 

Change directory 

Changes the actual drive and directory. 

File .DBF 

Contains a pop-up menu for ‘.DBF’ operations. 

New .DBF 

A ‘.DBF’ file is a table where columns, called Fields, must be specified and lines, 

called records, are added, edited and deleted by the program. 

Field characteristics are: 

the field name must be unique inside the same file, it is 

NAME 

composed of letters, number and underscore (_), but it 

must start with a letter and it is not case sensitive. 

TYPE the field type determinates the type of data it can hold. 

is the field total length in characters; it doesn’t matter 

LENGTH 

DECIMAL 

Field Types: 

of the type of data. 

is the length of positions after decimal point. This information 

is used normally for numeric fields. In this 

case, take note that the DECIMAL length, together 

with the decimal point, will subtract space for the integer 

part of the number from the total LENGTH of the 

filed.


C Character 

it is a text field long LENGTH characters. 

it is a numeric field long LENGTH characters with 

DECIMAL characters for decimal positions. Note that 

if LENGTH is 4 and DECIMAL is 0 (zero), the 

N Numeric 

field may contain integers from -999 to 9999; but if 

LENGTH is 4 and DECIMAL 1, the field may contain 

numbers from -9.9 to 99.9: two position for the integer 

part, one position for the decimal point and one position 

for decimal. 

D Date 

it is a date field: it contains only dates; the length 

should not be specified as it is automatically 8. 

it is a logical (boolean) field: it contains only TRUE, 

L Logic 

represented by "Y" or "T", or FALSE, represented by 

"N" or "F". The length should not be specified as it is 

automatically 1. 

it is a character field with unknown dimension. It is 

recorded into a parallel file with ‘.DBT’ extention. The 

M Memo 

original ‘.DBF’ file holds a space for a pointer inside 

the ‘.DBT’ file. The length of a Memo field is automatically 

10 and is referred to the memo pointer. 

After the function "NEW .DBF" is selected, a table for the field specifications appears. 

+--------------------------------+ 

| Database file structure | 

| | 

| Field Name Type Length Decimal | 

|--------------------------------| 

| | | 0| 0 | 

| | | | | 

| | | | | 

| | | | | 

| | | | | 

| | | | | 

| | | | | 

To navigate and to edit the table use the following keys: 

[ Up ]/[ Down ]/[ Left ][ Right ] move the cursor one position (up, down, left or right); 

[ PgUp ] move to previous screen page; 

[ PgDn ] move to next screen page; 

[ Ctrl+PgUp ] move to top of table; 

[ Ctrl+PgDn ] move to bottom of table; 

[ Ctrl+Home ] move to first column; 

[ Ctrl+End ] move to last column; 

[ Ctrl+Enter ] append a new empty line; 

[ Ctrl+F1 ] 

delete (cut) the current line and save a copy into the 

"clipboard"; 

[ Ctrl+F2 ] copy current line into the table "clipboard"; 

insert (paste) the content of the "clipboard" in the cur- 

[ Ctrl+F3 ] 

rent position; 

[ Enter ] start editing in the current position; 

[ Esc ] terminate; 

[ x ] any other key will be written in the current position. 

When the editing is terminated, press [ Esc ] and a dialog box will ask for the file name 

and the RDD. 

xBase files (.DBF) are not all equal, this way, when a new ‘.DBF’ file si created, the 

RDD (Replaceable Database Driver) is asked. The normal RDD is DBFNTX, the one 

used by Clipper.


Modify .DBF structure 

The modification of a ‘.DBF’ file structure is a delicate matter if it contains data. 

In fact, it is a data transfer from a source ‘.DBF’ file to a destination ‘.DBF’ file with 

a different structure. This way, the destination ‘.DBF’ will be updated only for the 

fields with the same name of the source one. The position may be different, but names 

cannot be changed (not so easily). 

Mistakes may be dangerous, so, before doing it, it is recommended a backup copy of 

the original ‘.DBF’ file. 

Open .DBF 

When a ‘.DBF’ file is opened, it becomes a alias, a logical file, placed inside a work 

area. The same ‘.DBF’ file may be opened inside different areas with different alias 

names. 

The required information to open the file are: 

File .NTX 

FILENAME 

ALIAS 

RDD 

SHARED 

READ ONLY 

Contains a pop-up menu for physical indexes operations. 

the physical file name. 

the alias name. If not assigned, it becomes automatically 

the same of FILENAME without extention. 

the Replaceable Database Driver to use to access to this 

file. 

a logical value: TRUE means that the file will be accessible 

to other users, FALSE means use exclusive. 

a logical value: TRUE means that the file will be only 

readable and no modification will be allowed, FALSE 

means that no restriction on editing will be made. 

New .NTX / new tag 

If the active area is used we have an active alias. In this case a index may be created. 

The index is a way to see the active alias ordered without changing the physical 

position of records. 

There are two words to understand: ORDER and INDEX-BAG. The index bag is the 

file that contains the information on the record ordering, the order is the rule followed 

to order the records. A index bag may contains one or more orders depending on the 

Replaceable Database Driver in use. 

Typical ‘.NTX’ file are index bag containing only one order. 

Depending on the RDD in use the following field may be filled. 

INDEX FILENAME 

this is the name of the index bag. 

the expression that defines the rule for the record or- 

KEY EXPRESSION 

dering. 

this is the name to give to the order (tag) when the RDD 

permits to have a index bag containing more than one 

ORDER NAME 

order. In the other case, the index bag name correspond 

to the order name. 

FOR EXPRESSION 

a FOR condition to filter records before indexing. 

Open index 

If a index file already exists, it can be associated to the active alias simply opening it. 

Take note that the system is not able to verify if the index belong the active alias 

and if it is not so a error will result.


Alias 

Order 

INDEX NAME 

is the name of the index bag file to open. 

Contains a pop-up menu for logical databases (alias) operations. 

Select 

Only one may be the active alias and with this function the active alias may be changed 

choosing from the list of used areas. 

Selecting the area number zero, no alias is active. 

Display structure 

With this function the active alias structure may be viewed. 

Close active alias 

Selecting this function the active alias is closed. That is: the ‘.DBF’ file and eventual 

indexes are closed. 

Close all aliases 

With this function all Aliases are closed. 

Contains a pop-up menu for logical indexes (orders). 

Relation 

Order list rebuild 

This function rebuild the indexes opened and associated to the active alias. 

Order set focus 

This function permits to change the active order selecting form the ones opened and 

associated to the active alias. 

Order list clear 

This function closes all orders associated to the active alias. 

Contains a pop-up menu for relations (links with other Aliases). 

Set relation 

This function permits to establish a relation between a alias and a Child alias showing 

as a result a unique database. 

CHILD is the alias name to connect to the active alias. 

is the relation expression that specify the rule for the relation. 

The value of this expression is the key to access 

EXPRESSION 

the Child alias: if this Child alias is accessed without 

index, it must be the record number, if this Child alias 

is accessed via index, it must be a valid index key. 

Clear relation 

This function eliminates any relation that originate form the active alias. 

RDD default 

Contains a pop-up menu for Replaceable Database Driver defaults. 

Show actual RDD default 

It simply shows the actual Replaceable Database Driver.


Set default RDD 

Select a new default Replaceable Database Driver. 

368.6.2 Menu Edit 

The menu Edit contains functions to access data from the active alias (the actual area). 

View 

This function permits you to view the active alias with eventual relations as a table. 

No edit is allowed. 

To navigate the table use the following keys. 

[ Enter ] start field editing. 

[ PgUp ] show previous screen page. 

[ PgDn ] show next screen page. 

[ Ctrl+PgUp ] show top of alias. 

[ Ctrl+PgDn ] show bottom of file. 

[ Ctrl+Home ] show the first column. 

[ Ctrl+End ] show last column. 

Edit/browse 

This function permits you to edit the active alias with eventual relations as a table. 

To navigate and edit the table use the following keys. 

[ Enter ] start field editing. 

[ PgUp ] show previous screen page. 

[ PgDn ] show next screen page. 

[ Ctrl+PgUp ] show top of alias. 

[ Ctrl+PgDn ] show bottom of file. 

[ Ctrl+Home ] show the first column. 

[ Ctrl+End ] show last column. 

[ Ctrl+Enter ] append a new empty record. 

[ Ctrl+F2 ] copy the current record. 

[ Ctrl+F3 ] append and paste a record. 

[ Ctrl+F4 ] 

paste a previously copied record, overwriting the content 

of the current one. 

[ Ctrl+Y ] delete or recall the current record. 

[ Ctrl+Del ] delete or recall the current record. 

When a memo field is edited: 

Replace 

[ Esc ] cancel and close the memo window. 

[ Ctrl+Y ] line delete. 

[ Ctrl+W ] save and close the memo window. 

The content of a Field of the active alias may be replaced with an expression. 

The required data is:


Recall 

Delete 

Pack 

FIELD TO REPLACE 

NEW VALUE EXPRESSION 

WHILE EXPRESSION 


the Field name to be replaced. 

the expression that obtain the new value for the selected 

Field. 

the WHILE condition expression: the replacement continue 

until this expression results True. The constant ‘.T.’ 

is ever True and is the default. 

the FOR condition expression: the replacement is made 

for all records that satisfy the condition. The constant 

‘.T.’ is ever True and is the default. 

The records signed for deletion (deleted but still there), may be recalled (undeleted). 

The required data is: 



the WHILE condition expression: the record recall continue 



the FOR condition expression: the record recall is made 



Deletes (sign for deletion) a group of record depending on the required conditions. 

The required data is: 



the WHILE condition expression: the record deletion continue 



the FOR condition expression: the record deletion is made 



This function eliminates definitely records previously deleted (signed for deletion). 

It may work only if the active alias was opened in exclusive mode. 

368.6.3 Menu Report 

The menu Report contains functions for data report (print). In particular, label files ‘.LBL’ and 

report file ‘.RPT’ may be created and used for printing. There is also another way to print, with 

the RPT() system that is available inside the nB internal editor DOC(). 

DBGOTOP() 

Moves the record pointer for the active alias at the first logical record. 

New label 

With this function can be created a standard label file (.LBL under the dBaseIII standard). 

Labels may be printed in more than one column and can contain 16 lines maximum. 

The label data is the following.


REMARK 

a label remark that will not be printed. 

HEIGHT the label vertical dimension. 

WIDTH the label horizontal dimension. 

MARGIN 

the left margin in characters. 

LINES 

the vertical spacing between labels. 

SPACES 

the horizontal spacing between labels in characters. 

ACROSS the number of label columns. 

LINE 1 The first line inside labels. 

LINE n The n-th line inside labels. 

LINE 16 The 16th line inside labels. 

The number of lines inside the labels depend on the HEIGHT and the maximum value is 

16. 

The label lines can contain constant string and/or string expressions. 

See the example below. 

Modify label 

Margin 

 

XXXXXXX|XXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX 


XXXX Height XXXX XXXXXXXXXXXXXXXX 



| 

| Lines 

| Spaces 

XX Line 1 XXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX 





XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX 





| | | 

| | | 

| | | 

+---------------- Across ---------------+ 

This function permits you to modify a label file. 

Label form 

This function permits you to print labels with the data provided by the active alias: one 

label each record. 

The following data is required. 

LABEL FILENAME the label filename. 

WHILE 

the WHILE condition: the label printing goes on as long 

as this condition remain True. 

FOR 

the FOR condition: only the records from the active alias 

that satisfy the condition are used for the label print.


New report 

This function permits you to create a standard report form file (.FRM under the dBaseIII 

standard). 

The informations to create a ‘.FRM’ file are divided into two parts: the head and groups; the 

columns. 

The first part: head and groups, requires the folliwing informations: 

PAGE WIDTH 

the page width in characters. 

LINES PER PAGE 

the usable lines per per page. 

LEFT MARGIN 

the left margin in characters. 

DOUBLE SPACED? 

double spaced print, yes or no. 

PAGE EJECT BEFORE PRINT? form feed before print, yes or no. 

PAGE EJECT AFTER PRINT? form feed after print, yes or no. 

PLAIN PAGE? 

plain page, yes or no. 

PAGE HEADER 

the page header, max 4 lines (the separation between one 

line and the other is obtained writing a semicolon, ";"). 

GROUP HEADER 

the group title. 

GROUP EXPRESSION 

the group expression (when it changes, the group changes) 

SUMMARY REPORT ONLY? only totals and no columns, yes or no. 

PAGE EJECT AFTER GROUP? form feed when the group changes, yes or no. 

SUB GROUP HEADER 

sub group title. 

SUB GROUP EXPRESSION the sub group expression. 

The second part: columns, requires the following informations structured in table form: 

COLUMN HEADER 

column head description (it can contain 4 lines separated 

with a semicolon). 

CONTENT 

the column expression. 

WIDTH the column width. 

DEC. 

the decimal length for numeric columns. 

TOTALS 

totals to be calculated, yes or no (usefull only for numeric 

columns). 

To navigate and to edit the table use the following keys: 

[ Up ]/[ Down ]/[ Left ][ Right ] move the cursor one position (up, down, left or right); 

[ PgUp ] move to previous screen page; 

[ PgDn ] move to next screen page; 

[ Ctrl+PgUp ] move to top of table; 

[ Ctrl+PgDn ] move to bottom of table; 

[ Ctrl+Home ] move to first column; 

[ Ctrl+End ] move to last column; 

[ Ctrl+Enter ] append a new empty line; 

[ Ctrl+F1 ] 

delete (cut) the current line and save a copy into the "clipboard"; 

[ Ctrl+F2 ] copy current line into the table "clipboard"; 

[ Ctrl+F3 ] 

insert (paste) the content of the "clipboard" in the current 

position; 

[ Enter ] start editing in the current position; 

[ Esc ] terminate; 

[ x ] any other key will be written in the current position. 

When the editing is terminated, press [ Esc ] and a dialog box will ask for the name to give 

to the report form file. 

Modify report 

This function permits you to modify a standard report form file (.FRM under the dBaseIII


standard). 

Report form 

This function permits you to print a report form with the data provided by the active alias. 

The following data is required. 

REPORT FORM FILENAME the label filename. 

WHILE 

the WHILE condition: the form printing goes on as long 

as this condition remain True. 

FOR 

the FOR condition: only the records from the active alias 

that satisfy the condition are used for the report form print. 

Create/modify/print text 

This function activates the text editor. 

368.6.4 Menu HTF 

The menu Htf helps on creating and accessing the "Help Text Files". This name, help text file, is 

just the name given to it. 

A text (Ascii) file prepared like this manual may be transformed into a "Help Text File" that is a 

simple text with pointers. 

Open help text file 

This function permits to open a Help Text File and browse it. The Help Text File name is 

required. 

New help text file 

This function permits to create a new "Help Text File" that is a help file under the nB style. 

The source is an Ascii file where three kind of information are available: Normal text, 

Indexes and pointers. 

Indexes and Pointers are word or phrases delimited with user defined delimiters; indexes 

are placed inside the text to indicate an argument, pointers are placed inside the text to 

indicate a reference to indexes. 

Inside this manual, indexes are delimited with ## and ##, so the titles are here indexes; 

pointers are delimited with < and >. 

Only one index per line is allowed, only one pointer per line is allowed. 

The Delimiters used do identify indexes and pointers are user defined; the _start_ identifier 

symbol can be equal to the _end_ identifier symbol. The symbols used for indexes cannot 

be used for the pointers. 

So, the informations required are: 

SOURCE TEXT FILENAME the filename of the text source file. 

DESTINATION FILENAME 

the filename of the destination Help Text File (suggested 

‘.HLP’ extention). 

INDEX START CODE 

the index start symbol; suggested ##. 

INDEX END CODE 

the index end symbol; suggested ##. 

POINTER START CODE 

the pointer start symbol; suggested .


New HTML file 

This function permits to create a new HTML file form a text file formatted to obtain a HTF 

file. 

The informations required are: 

SOURCE TEXT FILENAME the filename of the text source file. 

DESTINATION FILENAME 

the filename of the destination Help Text File (suggested 

‘.HLP’ extention). 

INDEX START CODE 

the index start symbol; suggested ##. 

INDEX END CODE 

the index end symbol; suggested ##. 

POINTER START CODE 

the pointer start symbol; suggested . 

HTML TITLE the title for the html page. 

368.6.5 Menu Macro 

The menu Macro helps on creating macros (programs) with a macro recorder, a macro "compiler" 

and a macro executor. 

Start recording 

This function simply starts or pause the macro recording. The menu items that end with 

"&", may be recorded by this macro recorder. 

Save recording 

A recorded macro may be saved into a ASCII file that may be later modified or simply used 

as it is. The filename is requested. 

Erase recording 

While recording or when the macro recorder is paused, it is possible to erase all previous 

recording with this function. 

Edit recording 

While recording or when the macro recorder is paused, it is possible to edit all previous 

recording, for example adding more comments or simply to see what the recorder does. 

Macro compilation 

A macro file (a program) contained inside a ASCII file, may be compiled into a different 

file format to speed up execution. The source filename and the destination filename are 

requested. 

Load + execute macro 

A macro file (a program) in ASCII form or compiled, may be executed. 

A macro file may require some parameters. 

This function asks for the macro filename to start and the possible parameter to pass to it.


368.6.6 Menu Info 

The menu Info is the information menu. 

ABOUT 

a brief copyright notice. 

starts the browse of ‘NB.HLP’ , the nB Help Text File manual 

MANUAL BROWSE 

if it is present in the current directory or it is found in the 

PATH (the Dos SET PATH). 

[F1] HELP [F1] reminder. 

[F3] ALIAS INFO 

[F3] reminder. It shows all the available information on the 

active alias. 

[F5] SET OUTPUT TO [F5] reminder. It defines the output peripheral or file. 

368.6.7 Menu Doc 

This menu actually appears only inside the DOC() function, the nB text editor. 

New 

Open 

Save 

Save as 

It starts the editing of a new empty text. 

It opens for editing a new textfile. 

It saves the text file under editing. 

It saves the text file under editing asking for a new name. 

Set output to 

It permits to change the default output peripheral: the default is the screen. 

Print as it is 

It prints on the output peripheral the content of the text as it is. 

Print with RPT() once 

It prints on the output peripheral the content of the text only once replacing possible text 

variables. 

Print with RPT() std 

It prints on the output peripheral the content of the text repeating this print for every record 

contained inside the archive alias. 

Exit DOC() 

Terminates the use of DOC() the text/document editing/print function.


368.7 The text editor DOC() 

The function Doc() activates a simple text editor usefull to build some simple reports. 

Inside this function a menu is available and is activated pressing [ Alt+M ] or [ F10 ]. The Doc() 

menu is part of the nB menu system. 

DOC() may handle text files of a teorical maximum of 64K. 

DOC() may be particularly useful to create formatted text with variables identified by CHR(174) 

and CHR(175) delimiters: when an active alias exists, [ F2 ] gives a list of insertable fields. 

[ Esc ] Exit DOC(). 

[ F1 ] Call the help. 

[ F2 ] Field list. 

[ up ] / [ Ctrl+E ] Line up. 

[ down ] / [ Ctrl+X ] Line down. 

[ left ] / [ Ctrl+S ] Character left. 

[ right ] / [ Ctrl+D ] Character right. 

[ Ctrl+right ] / [ Ctrl+A ] Word left. 

[ Ctrl+left ] / [ Ctrl+F ] Word right. 

[ Home ] Line start. 

[ End ] Line end. 

[ Ctrl+Home ] Top window. 

[ Ctrl+End ] Bottom window. 

[ PgUp ] Previous window. 

[ PgDn ] Next window. 

[ Ctrl+PgUp ] Document start. 

[ Ctrl+PgDn ] End document. 

[ Del ] Delete character (right). 

[ Backspace ] Delete character Left. 

[ Tab ] Insert tab. 

[ Ins ] Toggle insert/overwrite. 

[ Enter ] Next line. 

[ Ctrl+Y ] Delete line. 

[ Ctrl+T ] Delete word right. 

[ F10 ] / [ Alt+M ] DOC() menu. 

368.8 The help text file 

nB provides a basic hypertext system to build simple help files. A source text file with "indexes" 

and "pointers" to indexes is translated into a "help text file" (a ‘.DBF’ file); then, this file is 

browsed by nB. 

The source file can have a maximum line width of 80 characters; each line can terminate with 

CR or CR+LF. 

"Indexes" are string delimited by index delimiters (default "##"); "pointers" are string delimited 

by pointer delimiters (default "") and refers to indexes. 

Inside a text, indexes must be unique; pointers can be repeated anywhere. A text can contain a 

maximum of 4000 indexes. 

Inside this manual, titles are delimited with "##" as they are indexes; strings delimited with "" identify a reference to a title with the same string.


To browse a previously created Help Text File, use the following keys: 

[ Esc ] Exit. 

[ UpArrow ] Move cursor up. 

[ DownArrow ] Move cursor down. 

[ PgUp ] Move cursor PageUp. 

[ PgDn ] Move cursor Pagedown. 

[ Ctrl+PgUp ] Move cursor Top. 

[ Ctrl+PgDn ] Move cursor Bottom. 

[ Enter ] Select a reference (pointer). 

[ ] Go to next selected reference (pointer). 

[ Shift+F3 ] Search for a new pattern. 

[ F3 ] Repeat previous search. 

368.9 Macro 

nB can execute (run) macro files. There may be three kind of macro files: ASCII (usually with 

.& extention); "compiled" (usually with .NB extention); EXE files (compiled with Clipper and 

linked). 

"Compiled" macro files are executed faster then the ASCII source files. 

EXE macro files are the fastest. 

368.9.1 Macro statements 

The statements recognised from nB are very similar to Clipper, with some restrictions. 

Note that: the FOR statement is not included; there is no function declaration; procedure calls 

cannot transfer variables; only public variables are allowed. 

PROCEDURE 

Procedures are the basic building blocks of a nB macro. 

Procedures are visible only inside the current macro file. 

The procedure structure is as follows: 

PROCEDURE procedure_name 

statements... 

[RETURN] 

statements... 

ENDPROCEDURE 

A procedure definition begins with a PROCEDURE declaration followed with the 

procedure_name and ends with ENDPROCEDURE. 

Inside the PROCEDURE - ENDPROCEDURE declaration are placed the executable 

statements which are executed when the procedure is called. 

Inside the PROCEDURE - ENDPROCEDURE declaration, the RETURN statement may 

appear. In this case, encountering this RETURN statement, the procedure execution is immediately 

terminated and control is passed to the statement following the calling one. 

The procedure definition do not permit to receive parameters from the calling statement.


DO PROCEDURE 

There is only one way to call a procedure: 

DO PROCEDURE procedure_name 

When the statement DO PROCEDURE is encountered, the control is passed to the begin of 

the called PROCEDURE. After the PROCEDURE execution, the control is returned to the 

statement following DO PROCEDURE. 

The procedure call do not permit to send parameters to the procedure. 


The BEGIN SEQUENCE - END structure permits to define a sequence of operation that 

may be broken. 

Inside nB, this control structure is useful only because there is the possibility to break the 

execution and pass control over the end of it. 

This way, encountering BREAK means: "go to end". 


statements... 

[BREAK] 

statements... 

END 

Inside nB, error exception handling is not supported. 

DO CASE 

This is a control structure where only the statements following a True CASE condition are 

executed. 

When the DO CASE statement is encountered, the following CASE statements are tested. 

The first time that a condition returns True, the CASE’s statements are executed and then 

control is passed over the END case. 

That is: only one CASE is taken into consideration. 

If no condition is True, the statements following OTHERWISE are executed. 

DO CASE 

CASE lCondition1 

statements... 

[CASE lCondition2] 

statements... 

[OTHERWISE] 

statements... 

END 

WHILE 

The structure WHILE - END defines a loop based on a condition: the loop is repeated until 

the condition is True. 

The loop execution may be broken with the EXIT statement: it transfer control after the 

END while. 

The LOOP statement may be use to repeat the loop: it transfer the control to the beginning 

of the loop. 

WHILE lCondition 

statements... 

[EXIT] 

statements... 

[LOOP] 

statements... 

END


IF 

The IF - END control structure executes a section of code if a specified condition is True. 

The structure can also specify alternative code to execute if the condition is False. 

IF lCondition1 

statements... 

[ELSE] 

statements... 

END 

368.9.2 Variable declaration 

Inside nB, variables are created using a specific function: 

MEMPUBLIC( "cVarName" ) 

For example, 

MEMPUBLIC( "Name" ) 

creates the variable Name. 

The scope of the created variable is global and there is no way to restrict the visibility of it. 

When a variable is no more needed or desired, it can be released: 

MEMRELEASE( "cVarName" ) 

The variable declaration do not defines the variable type. Every variable may receive any kind of 

data; that is that the type depends on the type of data contained. 

368.9.3 Macro structure 

A nB macro must be organised as follow. There may be two situations: Macros with procedures 

and macros without procedures. 

Macro with procedures: 

PROCEDURE procedure_name_1 

statements... 

[RETURN] 

statements... 

ENDPROCEDURE 


statements... 

[RETURN] 

statements... 

ENDPROCEDURE 

... 

... 

DO PROCEDURE procedure_name_n 

Macro without procedures: 

statements... 

statements... 

statements... 

statements... 

statements... 

nB Macros may be compiled with Clipper. To do so, the first structure example must be changed 

as follows:


#INCLUDE MACRO.CH 

DO PROCEDURE procedure_name_nth 

... 


statements... 

[RETURN] 

statements... 

ENDPROCEDURE 


statements... 

[RETURN] 

statements... 

ENDPROCEDURE 

... 

... 

To compile a macro with Clipper, the macro file name can be changed into ‘MACRO.PRG’ and 

RTLINK MACRO.RMK [Enter] 

should be started. 

368.9.4 Macro comments 

A nB Macro source file can contain comments. only the "//" comment is recognised! This way: 

* and /*...*/ will generate errors! 

ATTENTION: to simplify the macro interpretation, lines such as this: 

qqout( "You can’t do that // you can’t do that!" ) 

will generate an error as the interpreter will read only: 

qqout( "You can’t do that 

Sorry! 

368.9.5 Macro long lines split 

Inside a nB macro, long lines may be splitted using ";" (semicolon). Please note that: lines can 

only be splitted and not joined; a resulting command line cannot be longer then 254 characters. 

368.9.6 The macro recorder 

Inside the functions ASSIST() and DOC() is available the Macro recorder menu. 

When a macro recording is started, a "&" appears on the left side of the status bar. It it blinks, the 

recording is active, if it is stable, the recording is paused. 

The macro recording is not exactly a step-by-step recording of all action taken, but a translation 

(as good as possible) of what you have done.


The macro recorder is able to record only the menu functions that terminates with the "&" symbol 

and all what is inserted at the dot command line. 

The macro recording can be viewed and edited during the recording. The macro recording can 

be saved into a text file (a macro file). 

368.10 Data types 

The data types supported in the nB macro language are the same as Clipper: 

Array 

Character 

Code Block 

Numeric 

Date 

Logical 

Memo 

NIL 

368.10.1 Character 

The character data type identifies character strings of a fixed length. The character set corresponds 

to: CHR(32) through CHR(255) and the null character, CHR(0). 

Valid character strings consist of zero or more characters with a theoretical maximum of 65535 

characters. The real maximum dimension depends on the available memory. 

Character string constants are formed by enclosing a valid string of characters within a designed 

pair of delimiters. There are three possible delimiter pairs: 

two single quotes like ‘’string_constant’’; 

two double quotes like ‘"string_constant"’; 

left and right square brackets like ‘[string_constant]’. 

These three different kind of delimiters are available to resolve some possible problems: 

I don’t want it -> "I don’t want it" 

She said, "I love hin" -> ’She said, "I love hin"’ 

He said, "I don’t want it" -> [He said, "I don’t want it"] 

The following table shows all operations available inside nB for character data types. These 

operations act on one or more character expressions and the result is not necessarily a character 

data type. 

+ Concatenate. 

- Concatenate without intervening spaces. 

== Compare for exact equity. 

!=, , # Compare for inequity. 

< Compare for sorts before


Compare for sorts after. 

>= Compare for sorts after or same as. 

:= In line assign. 

$ Test for substring existence. 

ALLTRIM() Remove leading and trailing spaces. 

ASC() Convert to numeric ASCII code equivalent. 

AT() Locate substring position. 

CTOD() Convert to date. 

DESCEND() Convert to complemented form. 

EMPTY() Test for null or blank string. 

ISALPHA() Test for initial letter. 

ISDIGIT() Test for initial digit. 

ISLOWER() Test for initial lowercase letter. 

ISUPPER() Test for initial uppercase letter. 

LEFT() Extract substring form the left. 

LEN() Compute string length in characters. 

LOWER() Convert letters to lowercase. 

LTRIM() Remove leading spaces. 

PADC() Pad with leading and trailing spaces. 

PADL() Pad with leading spaces. 

PADR() Pad with trailing spaces. 

RAT() Locate substring position starting from the right. 

RIGHT() Extract substring form the right. 

RTRIM() Remove trailing spaces. 

SOUNDEX() Convert to soundex equivalent. 

SPACE() Create a blank string of a defined length. 

STRTRAN() Search and replace substring. 

STUFF() Replace substring. 

SUBSTR() Extract substring. 

TRANSFORM() Convert to formatted string. 

UPPER() Convert letters to uppercase 

VAL() Convert to numeric. 

VALTYPE() Evaluates data type directly. 

368.10.2 Memo 

The memo data type is used to represent variable length character data that can only exist in the 

form of a database field. 

Memo fields are not stored inside the main database file (.DBF) but inside a separate file (.DBT). 

A memo field can contain up to 65535 characters, that is the same maximum dimension of character 

fields. In fact, originally xBases, couldn’t have character string longer than 254 characters. 

As here memo fields are very similar to long character strings, you may forget that there is a 

difference. 

All the operations that may be applied to character strings, may be used with memo fields; the 

following functions may be use especially for memo fields or long character strings. 

HARDCR() Replace soft with hard carriage returns. 

MEMOEDIT() Edit contents. 

MEMOLINE() Extract a line of a text.


MEMOREAD() Read form a disk text file. 

MEMOTRAN() Replace soft and hard carriage returns. 

MEMOWRIT() Write to disk text file. 

MLCOUNT() Count lines. 

MLPOS() Compute position. 

368.10.3 Date 

The date data type is used to represent calendar dates. 

Supported dates are from 0100.01.01 to 2999.12.31 and null or blank date. 

The appearance of a date is controlled from SETVERB("DATEFORMAT"). The default is 

"dd/mm/yyyy" and it may easily changed for example with SETVERB("DATEFORMAT", 

"MM/DD/YYYY") to the US standard. 

There is no way to represent date constants; these must be replaced with the CTOD() function. 

For example if the date 11/11/1995 is to be written, the right way is: 

CTOD( "11/11/1995" ) 

The character string "11/11/1995" must respect the date format defined as before explained. 

The function CTOD() will accept only valid dates, and null dates: 

CTOD( "" ) 

A null date is ever less than any other valid date. 

The following table shows all operations available inside nB for date data types. These operations 

act on one or more date expressions and the result is not necessarily a character data type. 

+ Add a number of days to a date. 

- Subtract days to a date. 

== Compare for equity. 


< Compare for earlier 

Compare for later. 

>= Compare for later or same as. 


CDOW() Compute day of week name. 

CMONTH() Compute month name. 

DAY() Extract day number. 


DOW() Compute day of week. 

DTOC() 

Convert to character string with the format defined with 

SETVERB( "DATEFORMAT" ). 

DOTOS() Convert to character string in sorting format (YYYYMMDD). 

EMPTY() Test for null date. 

MONTH() Extract month number. 


YEAR() Extract entire year number, including century.


368.10.4 Numeric 

The numeric data type identifies real number. The theoretical range is form 10^-308 to 10^308 

but the numeric precision is guaranteed up to 16 significant digits, and formatting a numeric 

value for display is guaranteed up to a length of 32 (30 digits, a sign, and a decimal point). That 

is: numbers longer than 32 bytes may be displayed as asterisks, and digits other then most 16 

significant ones are displayed as zeroes. 

Numeric constants are written without delimiters. The following are valid constant numbers: 

12345 

12345.678 

-156 

+1256.789 

-.789 

If a numeric constant is delimited like character strings, it becomes a character string. 

The following table shows all operations available inside nB for numeric data types. These operations 

act on one or more numeric expressions and the result is not necessarily a numeric data 

type. 

+ Add or Unary Positive. 

- Subtract or Unary Negative. 

* 

Multiply. 

/ Divide. 

% Modulus. 

^, ** Exponentiate. 



< Compare for less than. 

>= Compare for less than or equal. 

> Compare for greater than. 

>= Compare for greater than or equal. 


ABS() Compute absolute value. 

CHR() Convert to ASCII character equivalent. 


EMPTY() Test for zero. 

EXP() Exponentiate with e as the base. 

INT() Convert to integer. 

LOG() Compute natural logarithm. 

MAX() Compute maximum. 

MIN() Compute minimum. 

ROUND() Round up or down() 

SQRT() Compute square root. 

STR() Convert to character. 

TRANSFORM() Convert to formatted string. 


Number appearence may be affected by SETVERB("FIXED") and consequently by 

SETVERB("DECIMALS"). If SETVERB("FIXED") is True, numbers are displayed with a fixed 

decimal position. The number of decimal positions is defined by SETVERB("DECIMALS"). For


that reason, the default is SETVERB("FIXED", .F.) and SETVERB("DECIMALS", 2), that is, 

no fixed decimal position, but if they will be activated, the default is two decimal digits. 

368.10.5 Logical 

The logical data type identifies Boolean values. 

Logical constants are: 

‘.T.’ True. 

‘.F.’ False. 

When editing a logical field, inputs may be: 

y, Y, t, T for True 

n, N, f, F for False 

The following table shows all operations available inside nB for logical data types. These operations 

act on one or more logical expressions and the result is not necessarily a logical data 

type. 

.AND. And. 

.OR. Or. 

.NOT. or ! 

Negate. 


!=, , or # Compare for inequity. 

Comparing two logical values, False (‘.F.’) is always less than True (‘.T.’). 

368.10.6 NIL 

NIL is not properly a data type, it represent the value of an uninitialised variable. 

Inside nB (like what it happens inside Clipper), variables are not declared with the data type that 

they will contain. This means that a variable can contain any kind of data. In fact, nB variables 

are pointer to data and a pointer to "nothing" is NIL. 

NIL may be used as constant for assignment or comparing purpose: 

NIL 

Fields (database fields) cannot contain NIL. 

The following table shows all operations available inside nB for the NIL data type. Except for 

these operations, attempting to operate on a NIL results in a runtime error. 



< Compare for less than. 

Compare for greater than. 

>= Compare for greater than or equal. 


EMPTY() Test for NIL. 

VALTYPE() Evaluates data type directly.


For the purpose of comparison, NIL is the only value that is equal to NIL. All other values are 

greater than NIL. 

Variables are created inside nB with MEMPUBLIC(). This function creates variables which will 

be automatically initialised to NIL. 

368.10.7 Array 

The array data type identifies a collection of related data items that share the same name. Each 

value in an array is referred to as an element. 

Array elements can be of any data type except memo (memo is available only inside database 

fields). For example the first element can be a character string, the second a number, the third a 

date and so on. Arrays can contain other arrays and code blocks as elements. 

The variable containing the array does not contains the entire array, but the reference to it. 

When the NIL type was described, it was cleared that variables doesn’t contains real data, 

but pointer to data. But this happens in a transparent way, that is that when the a variable is 

assigned to another (for example A := B) the variable receiving the assignment will receive 

a pointer to a new copy of the source data. This is not the same with arrays: assigning to a 

variable an array, will assign to that variable a pointer to the same source array and not to a 

new copy of it. 

If arrays are to be duplicated, the ACLONE() function is to be used. 

An array constant may be expressed using curly brackets {}. See the examples below. 

A := { "first_element", "second_element", "third_element" } 

With this example, the variable A contain the reference to an array with three element containing 

character string. 

A[1] == "first_element" 

A[2] == "second_element" 

A[3] == "third_element" 

Arrays may contain also no element: empty array and may be expressed as: 

{} 

The array element is identified by a number enclosed with square brackets, following the variable 

name containing the reference to the array. The first array element is one. 

If an array contains arrays, we obtain a multidimensional array. For example: 

A := { { 1, 2 }, { 3, 4 }, { 5, 6 } } 

is equivalent to the following table. 

1 2 

3 4 

5 6


With this example, the variable A contain the reference to a bidimensional array containing numbers. 

A[1,1] or A[1][1] contains 1 



and so on. 

As arrays may contain mixed data, it is the user who have to handle correctly the element numbers. 

For example: 

A := { "hello", { 3, 4 }, 1234 } 

A[1] == "hello" 

A[2] == reference to { 3, 4 } 

A[3] == 1234 



A[1,1] is an error! 

The following table shows all operations available inside nB for arrays. 


AADD() Add dynamically an element to an array. 

ACLONE() Create a copy of an array. 

ACOPY() Copy element by element an array to another. 

ADEL() Delete one element inside an array. 

AFILL() Fill all array elements with a value. 

AINS() Insert an element inside an array. 

ARRAY() Creates an array of empty elements. 

ASCAN() Scan the array elements. 

ASIZE() Resize an array. 

ASORT() Sort the array elements. 

EMPTY() Test for no elements. 


368.10.8 Code block 

The code block data type identifies a small piece of executable program code. 

A code block is something like a little user defined function where only a sequence of functions 

or assignments may appear: no loops, no IF ELSE END. 

A code block may receive argument and return a value after execution, just like a function. 

The syntax is: 

{ | [argument_list] | exp_list } 

That is: the argument_list is optional; the exp_list may contain one or more expressions separated 

with a comma.


For example, calling the following code block will give the string "hello world" as result. 

{ || "hello world" } 

The following code block require a numeric argument an returns the number passed as argument 

incremented: 

{ | n | n+1 } 

The following code block requires two numeric arguments and returns the sum of the two square 

radix: 

{ | nFirst, nSecond | SQRT(nFirst) + SQRT(nSecond) } 

But code blocks may contains more expressions and the result of the execution of the code block 

is the result of the last expression. 

The following code block executes in sequence some functions and give ever "hello world" as a 

result. 

{ | a, b | functionOne(a), functionTwo(b), "hello world" } 

To start the execution of a code block a function is used: EVAL() 

For example, a code block is assigned to a variable and then executed. 

B := { || "hello world" } 

EVAL( B ) == "hello world" 

Another example with a parameter. 

B := { | n | n+1 } 

EVAL( B, 1 ) == 2 

Another example with two parameters. 

B := { | nFirst, nSecond | SQRT(nFirst) + SQRT(nSecond) } 

EVAL( B, 2, 4 ) == 20 

And so on. 

The following table shows some operations available inside nB for code blocks: many functions 

use code blocks as argument. 


AEVAL() Evaluate (execute) a code block for each element in an array. 

BCOMPILE() Convert (compile) a character string into a code block. 

DBEVAL() 

Evaluate (execute) a code block for each record in the active 

alias. 

EVAL() Evaluate a code block once. 

VALTYPE() Evaluates data type directly.


368.11 Operators 

Here is a list with a brief description of the operators available inside nB. 

cString1 $ cString2 

Substring comparison. 

If cString1 is contained inside cString2 the result is true (‘.T.’). 

nNumber1 % nNumber2 

Modulus. 

The result is the remainder of nNumber1 divided by nNuber2. 

() 

Function or grouping indicator. 

nNumber1 * nNumber2 

Multiplication. 

nNumber1 ** nNumber2 

nNumber1 ^ nNumber2 

Exponentiation. 

nNumber1 + nNumber2 

dDate + nNumber 

Addition, unary positive. 

cString1 + cString2 

String concatenation. 

The result is a string beginning with the content of cString1 and following with the content of 

cString2. 

nNumber1 - nNumber2 

dDate1 - dDate2 

dDate - nNumber 

Subtraction, unary negative. 

cString1 - cString2 

String concatenation. 

The result is a string containing cString1 after trimming trailing blanks and cString2. 

idAlias->idField 

FIELD->idVar 

MEMVAR->idVar 

Alias assignment. 

The alias operator implicitly SELECTs the idAlias before evaluating idField. When the evaluation 

is complete, the original work area is SELECTed again. 

lCondition1 .AND. lCondition2 

Logical AND. 

.NOT. lCondition


Logical NOT. 

lCondition1 .OR. lCondition2 

Logical OR. 

nNumber1 / nNumber2 

Division. 

object:message[(argument list)] 

Send. 

idVar := exp 

Inline assign. 

exp1 exp2 

Greater than. 

exp1 >= exp2 

Greater than or equal. 

@idVar 

Pass-by-reference. 

[] 

aArray[nSubscript, ...] 

aArray[nSubscript1][nSubscript2] ... 

Array element indicator. 

368.12 Delimiters 

Here is the delimiter list recognised from nB. 

{ exp_list } 

Literal array delimiters. 

{ |param_list| exp_list } 

Code block delimiters. 

"cString" 

’cString’ 

[cString]


String delimiters. 

368.13 Code blocks 

A code block is a sequence of function, assignments and constant like the following: 

sqrt(10) 

nResult := 10 * nIndex 

Suppose that the above sequence of operations has a meaning for you. We want to create a box 

containing this sequence of operation. This box is contained inside a variable: 

bBlackBox := { || sqrt(10), nResult := 10 * nIndex } 

Note the comma used as separator. 

Now bBlackBox contains the small sequence seen before. To execute this sequence, the function 

EVAL() is used: 

EVAL(bBlackBox) 

The execution of the code block gives a result: the value of the last operation contained inside 

the code block. In this case it is the result of 10*nIndex. For that reason, if the execution of the 

code block must give a fixed result, it can terminate with a constant. 

A code block may receive parameters working like a function. Try to imagine that we need to do 

the following. 

function multiply( nVar1, nVar2 ) 

return nVar * nVar2 

endfunction 

A code block that does the same is: 

bMultiply := { | nVar1, nVar2 | nVar1 * nVar2 } 

To evaluate it, for example trying to multiply 10 * 5: 

nResult := EVAL( bMultiply, 10, 5 ) 

and nResult will contain 50. 

368.14 Standard functions 

With nB all Clipper standard functions may be used. Here follows a short description. 

368.14.1 AADD() 

Array add 

AADD(aTarget, expValue) ⇒ Value 

aTarget is the array to add a new element to. 

expValue is the value assigned to the new element. 

It increases the actual length of the target array by one. The newly created array element is


assigned the value specified by expValue. 

368.14.2 ABS() 

Absolute 

ABS(nExp) ⇒ nPositive 

nExp is the numeric expression to evaluate. 

ABS() returns a number representing the absolute value of its argument. 

368.14.3 ACLONE() 

Array clone 

ACLONE(aSource) ⇒ aDuplicate 

aSource 

ACLONE() returns a duplicate of aSource. 

368.14.4 ACOPY() 

Array copy 

is the array to duplicate. 

ACOPY(aSource, aTarget, 

[nStart], [nCount], [nTargetPos]) ⇒ aTarget 

aSource 

is the array to copy elements from. 

aTarget is the array to copy elements to. 

is the starting element position in the aSource array. If not 

nStart 

specified, the default value is one. 

is the number of elements to copy from the aSource array 

beginning at the nStart position. If nCount is not specified, 

nCount 

all elements in aSource beginning with the starting element 

are copied. 

is the starting element position in the aTarget array to receive 

nTargetPos 

elements from aSource. If not specified, the default value is 

one. 

ACOPY() is an array function that copies elements from the aSource array to the aTarget array. 

The aTarget array must already exist and be large enough to hold the copied elements.


368.14.5 ADEL() 

Array delete 

ADEL(aTarget, nPosition) ⇒ aTarget 

aTarget is the array to delete an element from. 

nPosition 

is the position of the target array element to delete. 

ADEL() is an array function that deletes an element from an array. The contents of the specified 

array element is lost, and all elements from that position to the end of the array are shifted up one 

element. The last element in the array becomes NIL. 

368.14.6 AEVAL() 

Array evaluation 

AEVAL(aArray, bBlock, 

[nStart], [nCount]) ⇒ aArray 

aArray is the array to be evaluated. 

bBlock is a code block to execute for each element encountered. 

nStart 

is the starting element. If not specified, the default is element 

one. 

nCount 

is the number of elements to process from nStart. If not specified, 

the default is all elements to the end of the array. 

AEVAL() is an array function that evaluates a code block once for each element of an array, 

passing the element value and the element index as block parameters. The return value of the 

block is ignored. All elements in aArray are processed unless either the nStart or the nCount 

argument is specified. 

368.14.7 AFILL() 

Array fill 

AFILL(aTarget, expValue, 

[nStart], [nCount]) ⇒ aTarget 

aTarget is the array to fill. 

expValue 

is the value to place in each array element. It can be an expression 

of any valid data type. 

nStart 

is the position of the first element to fill. If this argument is 

omitted, the default value is one. 

is the number of elements to fill starting with element nStart. 

nCount 

If this argument is omitted, elements are filled from the starting 

element position to the end of the array. 

AFILL() is an array function that fills the specified array with a single value of any data type 

(including an array, code block, or NIL) by assigning expValue to each array element in the 

specified range.


368.14.8 AINS() 

Array insert 

AINS(aTarget, nPosition) ⇒ aTarget 

aTarget is the array into which a new element will be inserted. 

nPosition 

is the position at which the new element will be inserted. 

AINS() is an array function that inserts a new element into a specified array. The newly inserted 

element is NIL data type until a new value is assigned to it. After the insertion, the last element 

in the array is discarded, and all elements after the new element are shifted down one position. 

368.14.9 ALERT() 

ALERT( cMessage, [aOptions] ) ⇒ nChoice 

is the message text displayed, centered, in the alert box. If the 

cMessage 

message contains one or more semicolons, the text after the 

semicolons is centered on succeeding lines in the dialog box. 

aOptions defines a list of up to 4 possible responses to the dialog box. 

ALERT() returns a numeric value indicating which option was chosen. If the Esc key is pressed, 

the value returned is zero. The ALERT() function creates a simple modal dialog. The user can 

respond by moving a highlight bar and pressing the Return or SpaceBar keys, or by pressing 

the key corresponding to the first letter of the option. If aOptions is not supplied, a single "Ok" 

option is presented. 

368.14.10 ALIAS() 

ALIAS([nWorkArea]) ⇒ cAlias 

nWorkArea 

is any work area number. 

ALIAS() returns the alias of the specified work area as a character string. If nWorkArea is not 

specified, the alias of the current work area is returned. If there is no database file in USE for the 

specified work area, ALIAS() returns a null string (""). 

368.14.11 ALLTRIM() 

ALLTRIM(cString) ⇒ cTrimmedString 

cString is the character expression to trim. 

ALLTRIM() returns a character string with leading and trailing spaces removed.


368.14.12 ARRAY() 

ARRAY(nElements [, nElements...]) ⇒ aArray 

nElements 

is the number of elements in the specified dimension. 

ARRAY() is an array function that returns an uninitialized array with the specified number of 

elements and dimensions. 

368.14.13 ASC() 

ASCII 

ASC(cExp) ⇒ nCode 

cExp is the character expression to convert to a number. 

ASC() returns an integer numeric value in the range of zero to 255 , representing the ASCII value 

of cExp. 

368.14.14 ASCAN() 

Array scan 

ASCAN(aTarget, expSearch, 

[nStart], [nCount]) ⇒ nStoppedAt 

aTarget is the array to scan. 

is either a simple value to scan for, or a code block. If 

expSearch 

expSearch is a simple value it can be character, date, logical, 

or numeric type. 

is the starting element of the scan. If this argument is not spec- 

nStart 

ified, the default starting position is one. 

is the number of elements to scan from the starting position. 

nCount 

If this argument is not specified, all elements from the starting 

element to the end of the array are scanned. 

ASCAN() returns a numeric value representing the array position of the last element scanned. 

If expSearch is a simple value, ASCAN() returns the position of the first matching element, or 

zero if a match is not found. If expSearch is a code block, ASCAN() returns the position of the 

element where the block returned true (‘.T.’). 

368.14.15 ASIZE() 

Array size 

ASIZE(aTarget, nLength) ⇒ aTarget 

aTarget is the array to grow or shrink. 

nLength is the new size of the array.


ASIZE() is an array function that changes the actual length of the aTarget array. The array is 

shortened or lengthened to match the specified length. If the array is shortened, elements at the 

end of the array are lost. If the array is lengthened, new elements are added to the end of the array 

and assigned NIL. 

368.14.16 ASORT() 

Array sort 

ASORT(aTarget, [nStart], 

[nCount], [bOrder]) ⇒ aTarget 

aTarget is the array to sort. 

nStart 

is the first element of the sort. If not specified, the default 

starting position is one. 

nCount 

is the number of elements to sort. If not specified, all elements 

in the array beginning with the starting element are sorted. 

bOrder 

is an optional code block used to determine sorting order. If 

not specified, the default order is ascending. 

ASORT() is an array function that sorts all or part of an array containing elements of a single data 

type. Data types that can be sorted include character, date, logical, and numeric. If the bOrder 

argument is not specified, the default order is ascending. Each time the block is evaluated, two 

elements from the target array are passed as block parameters. The block must return true (‘.T.’) 

if the elements are in sorted order. 

368.14.17 AT() 

AT(cSearch, cTarget) ⇒ nPosition 

cSearch 

is the character substring for which to search. 

cTarget is the character string to search. 

AT() returns the position of the first instance of cSearch within cTarget as an integer numeric 

value. If cSearch is not found, AT() returns zero. 

AT() is a character function used to determine the position of the first occurrence of a character 

substring within another string. 

368.14.18 ATAIL() 

Array TAIL 

ATAIL(aArray) ⇒ Element 

aArray is the array. 

ATAIL() is an array function that returns the highest numbered element of an array. It can be used 

in applications as shorthand for aArray[LEN(aArray)] when you need to obtain the last element 

of an array.


368.14.19 BIN2I() 

Binary to integer 

BIN2I(cSignedInt) ⇒ nNumber 

cSignedInt 

is a character string in the form of a 16-bit signed integer 

number--least significant byte first. 

BIN2I() returns an integer obtained converting the first two byte contained inside cSignedInt. 

368.14.20 BIN2L() 

Binary to long 

BIN2L(cSignedInt) ⇒ nNumber 

cSignedInt 

is a character string in the form of a 32-bit signed integer 


BIN2L() returns an integer obtained from the first tour characters contained in cSignedInt. 

368.14.21 BIN2W() 

Binary to word 

BIN2W(cUnsignedInt) ⇒ nNumber 

cUnsignedInt 

is a character string in the form of a 16-bit unsigned integer 


BIN2W() returns an integer obtained from the first two characters contained in cSignedInt. 

368.14.22 BOF() 

Begin of file 

BOF() ⇒ lBoundary 

BOF() returns true (‘.T.’) after an attempt to SKIP backward beyond the first logical record in 

a database file; otherwise, it returns false (‘.F.’). If there is no database file open in the current 

work area, BOF() returns false (‘.F.’). If the current database file contains no records, BOF() 

returns true (‘.T.’).


368.14.23 CDOW() 

Character day of week 

CDOW(dExp) ⇒ cDayName 

dExp is the date value to convert. 

CDOW() returns the name of the day of the week as a character string. The first letter is uppercase 

and the rest of the string is lowercase. For a null date value, CDOW() returns a null string (""). 

368.14.24 CHR() 

Character 

CHR(nCode) ⇒ cChar 

nCode 

is an ASCII code in the range of zero to 255. 

CHR() returns a single character value whose ASCII code is specified by nCode. 

368.14.25 CMONTH() 

Character month 

CMONTH(dDate) ⇒ cMonth 

dDate is the date value to convert. 

CMONTH() returns the name of the month as a character string from a date value with the first 

letter uppercase and the rest of the string lowercase. For a null date value, CMONTH() returns a 

null string (""). 

368.14.26 COL() 

Column 

COL() ⇒ nCol 

COL() is a screen function that returns the current column position of the cursor. The value of 

COL() changes whenever the cursor position changes on the screen. 

368.14.27 COLORSELECT() 

COLORSELECT(nColorIndex) ⇒ NIL 

nColorIndex 

is a number corresponding to the ordinal positions in the current 

list of color attributes, as set by SETCOLOR(). 

COLORSELECT() activates the specified color pair from the current list of color attributes (es-


tablished by SETCOLOR()). 

368.14.28 CTOD() 

Character to date 

CTOD(cDate) ⇒ dDate 

cDate 

is a character string consisting of numbers representing the 

month, day, and year separated by any character other than a 

number. The month, day, and year digits must be specified in 

accordance with the SET DATE format. If the century digits 

are not specified, the century is determined by the rules of 

SET EPOCH. 

CTOD() returns a date value. If cDate is not a valid date, CTOD() returns an empty date. 

368.14.29 CURDIR() 

Current directory 

CURDIR([cDrivespec]) ⇒ cDirectory 

cDrivespec 

specifies the letter of the disk drive to query. If not specified, 

the default is the current DOS drive. 

CURDIR() returns the current DOS directory of the drive specified by cDrivespec as a character 

string without either leading or trailing backslash (\) characters. 

368.14.30 DATE() 

DATE() ⇒ dSystemDate 

DATE() returns the system date as a date value. 

368.14.31 DAY() 

DAY(dDate) ⇒ nDay 

dDate is a date value to convert. 

DAY() returns the day number from dDate.


368.14.32 DBAPPEND() 

DBAPPEND([lReleaseRecLocks]) ⇒ NIL 

lReleaseRecLocks 

DBAPPEND() adds a new empty record to the active alias. 

368.14.33 DBCLEARFILTER() 

DBCLEARFILTER() ⇒ NIL 

is a logical data type that if true (‘.T.’), clears all 

pending record locks, then appends the next record. If 

lReleaseRecLocks is false (‘.F.’), all pending record locks 

are maintained and the new record is added to the end of 

the Lock List. The default value of lReleaseRecLocks is true 

(‘.T.’). 

DBCLEARFILTER() clears the logical filter condition, if any, for the current work area. 

368.14.34 DBCLEARINDEX() 

DBCLEARINDEX() ⇒ NIL 

DBCLEARINDEX() closes any active indexes for the active alias. 

368.14.35 DBCLEARRELATION() 

DBCLEARRELATION() ⇒ NIL 

DBCLEARRELATION() clears any active relations for the active alias. 

368.14.36 DBCLOSEALL() 

DBCLOSEALL() ⇒ NIL 

DBCLOSEALL() releases all occupied work areas from use. It is equivalent to calling DB- 

CLOSEAREA() on every occupied work area. 

Attention: DBCLOSEALL() cannot be used inside a "compiled" macro as this will stop the 

macro execution. In substitution, DBCLOSE() should be used. 

368.14.37 DBCLOSEAREA() 

DBCLOSEAREA() ⇒ NIL 

DBCLOSEAREA() releases the current work area from use.


368.14.38 DBCOMMIT() 

DBCOMMIT() ⇒ NIL 

DBCOMMIT() causes all updates to the current work area to be written to disk. All updated 

database and index buffers are written to DOS and a DOS COMMIT request is issued for the 

database (.dbf) file and any index files associated with the work area. Inside a network environment, 

DBCOMMIT() makes database updates visible to other processes. To insure data integrity, 

issue DBCOMMIT() before an UNLOCK operation. 

368.14.39 DBCOMMITALL() 

DBCOMMITALL() ⇒ NIL 

DBCOMMITALL() causes all pending updates to all work areas to be written to disk. It is equivalent 

to calling DBCOMMIT() for every occupied work area. 

368.14.40 DBCREATE() 

DBCREATE(cDatabase, aStruct, [cDriver]) ⇒ NIL 

cDatabase 

aStruct 

cDriver 

is the name of the new database file, with an optional drive and 

directory, specified as a character string. If specified without 

an extension (.dbf) is assumed. 

is an array that contains the structure of cDatabase as a series 

of subarrays, one per field. Each subarray contains the definition 

of each field’s attributes and has the following structure: 

aStruct[n][1] == cName 

aStruct[n][2] == cType 

aStruct[n][3] == nLength 

aStruct[n][4] == nDecimals 

specifies the replaceable database driver (RDD) to use to process 

the current work area. cDriver is name of the RDD specified 

as a character expression. 

DBCREATE() is a database function that creates a database file from an array containing the 

structure of the file. 

368.14.41 DBCREATEINDEX() 

DBCREATEINDEX(cIndexName, cKeyExpr, bKeyExpr, [lUnique]) 

⇒ NIL 

cIndexName 

cKeyExpr 

bKeyExpr 

lUnique 

is a character value that specifies the filename of the index file 

(order bag) to be created. 

is a character value that expresses the index key expression in 

textual form. 

is a code block that expresses the index key expression in executable 

form. 

is an optional logical value that specifies whether a unique 

index is to be created. If lUnique is omitted, the current global 

_SET_UNIQUE setting is used.


DBCREATEINDEX() creates an index for the active alias. If the alias has active indexes, they 

are closed. 

368.14.42 DBDELETE() 

DBDELETE() ⇒ NIL 

DBDELETE() marks the current record as deleted (*). Records marked for deletion can be filtered 

using SET DELETED or removed from the file using the PACK command. 

368.14.43 DBEVAL() 

DB evaluate 

DBEVAL(bBlock, 

[bForCondition], 

[bWhileCondition], 

[nNextRecords], 

[nRecord], 

[lRest]) ⇒ NIL 

bBlock 

bForCondition 

bWhileCondition 

nNextRecords 

nRecord 

lRest 

is a code block to execute for each record processed. 

the FOR condition expressed as code block. 

the WHILE condition expressed as code block. 

is an optional number that specifies the number of records to 

process starting with the current record. It is the same as the 

NEXT clause. 

is an optional record number to process. If this argument is 

specified, bBlock will be evaluated for the specified record. 

This argument is the same as the RECORD clause. 

is an optional logical value that determines whether the scope 

of DBEVAL() is all records, or, starting with the current 

record, all records to the end of file. 

DBEVAL() is a database function that evaluates a single block for each record within the active 

alias. 

368.14.44 DBFILTER() 

DBFILTER() ⇒ cFilter 

BFILTER() returns the filter condition defined in the current work area as a character string. If 

no FILTER has been SET, DBFILTER() returns a null string (""). 

368.14.45 DBGOBOTTOM() 

DBGOBOTTOM() ⇒ NIL 

DBGOBOTTOM() moves to last logical record in the active alias.


368.14.46 DBGOTO() 

DBGOTO(nRecordNumber) ⇒ NIL 

nRecordNumber 

is a numeric value that specifies the record number of the desired 

record. 

DBGOTO() moves to the record whose record number is equal to nRecordNumber. If no such 

record exists, the work area is positioned to LASTREC() + 1 and both EOF() and BOF() return 

true (‘.T.’). 

368.14.47 DBGOTOP() 

DBGOTOP() ⇒ NIL 

DBGOTOP() moves to the first logical record in the current work area. 

368.14.48 DBRECALL() 

DBRECALL() ⇒ NIL 

DBRECALL() causes the current record to be reinstated if it is marked for deletion. 

368.14.49 DBREINDEX() 

DBREINDEX() ⇒ NIL 

DBREINDEX() rebuilds all active indexes associated with the active alias. 

368.14.50 DBRELATION() 

DBRELATION(nRelation) ⇒ cLinkExp 

nRelation 

is the position of the desired relation in the list of active alias 

relations. 

DBRELATION() returns a character string containing the linking expression of the relation specified 

by nRelation. If there is no RELATION SET for nRelation, DBRELATION() returns a null 

string (""). 

368.14.51 DBRLOCK() 

DB record lock 

DBRLOCK([nRecNo]) ⇒ lSuccess 

nRecNo 

is the record number to be locked. The default is the current 

record. 

DBRLOCK() is a database function that locks the record identified by nRecNo or the current


record. 

368.14.52 DBRLOCKLIST() 

DBRLOCKLIST() ⇒ aRecordLocks 

DBRLOCKLIST() returns a one-dimensional array of the locked records in the active alias. 

368.14.53 DBRSELECT() 

DB relation select 

DBRSELECT(nRelation) ⇒ nWorkArea 

nRelation 

is the position of the desired relation in the list of current work 

area relations. 

DBRSELECT() returns the work area number of the relation specified by nRelation as an integer 

numeric value. If there is no RELATION SET for nRelation, DBRSELECT() returns zero. 

368.14.54 DBRUNLOCK() 

DB relation unlock 

DBRUNLOCK([nRecNo]) ⇒ NIL 

nRecNo 

is the record number to be unlocked. The default is all previously 

locked records. 

DBRUNLOCK() is a database function that unlocks the record identified by nRecNo or all 

locked records. 

368.14.55 DBSEEK() 

DBSEEK(expKey, [lSoftSeek]) ⇒ lFound 

expKey 

lSoftSeek 

is a value of any type that specifies the key value associated 

with the desired record. 

is an optional logical value that specifies whether a soft seek 

is to be performed. This determines how the work area is positioned 

if the specified key value is not found. If lSoftSeek is 

omitted, the current global _SET_SOFTSEEK setting is used. 

DBSEEK() returns true (‘.T.’) if the specified key value was found; otherwise, it returns false 

(‘.F.’).


368.14.56 DBSELECTAREA() 

DBSELECTAREA(nArea | cAlias) ⇒ NIL 

nArea 

cAlias 

is a numeric value between zero and 250, inclusive, that specifies 

the work area being selected. 

is a character value that specifies the alias of a currently occupied 

work area being selected. 

DBSELECTAREA() causes the specified work area to become the current work area. All subsequent 

database operations will apply to this work area unless another work area is explicitly 

specified for an operation. 

368.14.57 DBSETDRIVER() 

DBSETDRIVER([cDriver]) ⇒ cCurrentDriver 

cDriver 

DBSETDRIVER() returns the name of the current default driver. 

368.14.58 DBSETFILTER() 

DBSETFILTER(bCondition, [cCondition]) ⇒ NIL 

bCondition 

cCondition 

is an optional character value that specifies the name of the 

database driver that should be used to activate and manage 

new work areas when no driver is explicitly specified. 

is a code block that expresses the filter condition in executable 

form. 

is a character value that expresses the filter condition in textual 

form. If cCondition is omitted, the DBSETFILTER() 

function will return an empty string for the work area. 

DBSETFILTER() sets a logical filter condition for the current work area. When a filter is set, 

records which do not meet the filter condition are not logically visible. That is, database operations 

which act on logical records will not consider these records. The filter expression supplied 

to DBSETFILTER() evaluates to true (‘.T.’) if the current record meets the filter condition; 

otherwise, it should evaluate to false (‘.F.’). 

368.14.59 DBSETINDEX() 

DBSETINDEX(cOrderBagName) ⇒ NIL 

cOrderBagName 

is a character value that specifies the filename of the index file 

(index bag) to be opened. 

DBSETINDEX() is a database function that adds the contents of an Order Bag into the Order List 

of the current work area. Any Orders already associated with the work area continue to be active.


If the newly opened Order Bag is the only Order associated with the work area, it becomes the 

controlling Order; otherwise, the controlling Order remains unchanged. If the Order Bag contains 

more than one Order, and there are no other Orders associated with the work area, the first Order 

in the new Order Bag becomes the controlling Order. 

368.14.60 DBSETORDER() 

DBSETORDER(nOrderNum) ⇒ NIL 

nOrderNum 

is a numeric value that specifies which of the active indexes is 

to be the controlling index. 

DBSETORDER() controls which of the active alias’ active indexes is the controlling index. 

368.14.61 DBSETRELATION() 

DBSETRELATION(nArea | cAlias, bExpr, [cExpr]) ⇒ NIL 

nArea 

cAlias 

bExpr 

cExpr 

is a numeric value that specifies the work area number of the 

child work area. 

is a character value that specifies the alias of the child work 

area. 

is a code block that expresses the relational expression in executable 

form. 

is an optional character value that expresses the relational expression 

in textual form. If cExpr is omitted, the DBRELA- 

TION() function returns an empty string for the relation. 

DBSETRELATION() relates the work area specified by nArea or cAlias (the child work area), 

to the current work area (the parent work area). Any existing relations remain active. 

368.14.62 DBSKIP() 

DBSKIP([nRecords]) ⇒ NIL 

nRecords 

is the number of logical records to move, relative to the current 

record. A positive value means to skip forward, and a 

negative value means to skip backward. If nRecords is omitted, 

a value of 1 is assumed. 

DBSKIP() moves either forward or backward relative to the current record. Attempting to skip 

forward beyond the last record positions the work area to LASTREC() + 1 and EOF() returns 

true (‘.T.’). Attempting to skip backward beyond the first record positions the work area to the 

first record and BOF() returns true (‘.T.’).


368.14.63 DBSTRUCT() 

DBSTRUCT() ⇒ aStruct 

DBSTRUCT() returns the structure of the current database file in an array whose length is equal 

to the number of fields in the database file. Each element of the array is a subarray containing 

information for one field. The subarrays have the following format: 

aStruct[n][1] == cName 

aStruct[n][2] == cType 

aStruct[n][3] == nLength 

aStruct[n][4] == nDecimals 

If there is no database file in USE in the current work area, DBSTRUCT() returns an empty array 

({}). 

368.14.64 DBUNLOCK() 

DBUNLOCK() ⇒ NIL 

DBUNLOCK() releases any record or file locks obtained by the current process for the current 

work area. DBUNLOCK() is only meaningful on a shared database in a network environment. 

368.14.65 DBUNLOCKALL() 

DBUNLOCKALL() ⇒ NIL 

DBUNLOCKALL() releases any record or file locks obtained by the current process for any work 

area. DBUNLOCKALL() is only meaningful on a shared database in a network environment. 

368.14.66 DBUSEAREA() 

DBUSEAREA( [lNewArea], [cDriver], cName, [xcAlias], 

[lShared], [lReadonly]) ⇒ NIL 

lNewArea 

cDriver 

cName 

xcAlias 

lShared 

is an optional logical value. A value of true (‘.T.’) selects the 

lowest numbered unoccupied work area as the current work 

area before the use operation. If lNewArea is false (‘.F.’) 

or omitted, the current work area is used; if the work area is 

occupied, it is closed first. 

is an optional character value. If present, it specifies the name 

of the database driver which will service the work area. If 

cDriver is omitted, the current default driver is used. 

specifies the name of the database (.dbf) file to be opened. 

is an optional character value. If present, it specifies the alias 

to be associated with the work area. The alias must constitute 

a valid identifier. A valid xcAlias may be any legal identifier 

(i.e., it must begin with an alphabetic character and may contain 

numeric or alphabetic characters and the underscore). If 

xcAlias is omitted, a default alias is constructed from cName. 

is an optional logical value. If present, it specifies whether the 

database (.dbf) file should be accessible to other processes 

on a network. A value of true (‘.T.’) specifies that other processes 

should be allowed access; a value of false (‘.F.’) specifies 

that the current process is to have exclusive access. If 

lShared is omitted, the current global _SET_EXCLUSIVE 

setting determines whether shared access is allowed.


lReadonly 

DBUSEAREA() opens the specified database (.DBF). 

368.14.67 DBDELETE() 

DELETED() ⇒ lDeleted 

is an optional logical value that specifies whether updates to 

the work area are prohibited. A value of true (‘.T.’) prohibits 

updates; a value of false (‘.F.’) permits updates. A value 

of true (‘.T.’) also permits read-only access to the specified 

database (.dbf) file. If lReadonly is omitted, the default value 

is false (‘.F.’). 

DELETED() returns true (‘.T.’) if the current record is marked for deletion; otherwise, it returns 

false (‘.F.’). If there is no database file in USE in the current work area, DELETED() returns 

false (‘.F.’). 

368.14.68 DESCEND() 

DESCEND(exp) ⇒ ValueInverted 

exp 

is any valid expression of character, date, logical, or numeric 

type. 

DESCEND() returns an inverted expression of the same data type as the exp, except for dates 

which return a numeric value. A DESCEND() of CHR(0) always returns CHR(0). 

368.14.69 DEVOUT() 

Device output 

DEVOUT(exp, [cColorString]) ⇒ NIL 

exp is the value to display. 

cColorString is an optional argument that defines the display color of exp. 

DEVOUT() is a full-screen display function that writes the value of a single expression to the 

current device at the current cursor or printhead position. 

368.14.70 DEVOUTPICT() 

Device output picture 

DEVOUTPICT(exp, cPicture, [cColorString]) ⇒ NIL 


cPicture 

defines the formatting control for the display of exp. 

cColorString is an optional argument that defines the display color of exp.


DEVOUTPICT() is a full-screen display function that writes the value of a single expression to 

the current device at the current cursor or printhead position. 

368.14.71 DEVPOS() 

Device position 

DEVPOS(nRow, nCol) ⇒ NIL 

nRow, nCol 

are the new row and column positions of the cursor or printhead. 

DEVPOS() is an environment function that moves the screen or printhead depending on the 

current DEVICE. 

368.14.72 DIRECTORY() 

DIRECTORY(cDirSpec, [cAttributes]) ⇒ aDirectory 

cDirSpec 

cAttributes 

identifies the drive, directory and file specification for the directory 

search. Wildcards are allowed in the file specification. 

If cDirSpec is omitted, the default value is *.*. 

specifies inclusion of files with special attributes in the returned 

information. cAttributes is a string containing one or 

more of the following characters: 

H Include hidden files 

S Include system files 

D Include directories 

V Search for the DOS volume label only 

Normal files are always included in the search, unless you 

specify V. 

DIRECTORY() returns an array of subarrays, with each subarray containing information about 

each file matching cDirSpec. The subarray has the following structure: 

aDirectory[n][1] == cName 

aDirectory[n][2] == cSize 

aDirectory[n][3] == dDate 

aDirectory[n][4] == cTime 

aDirectory[n][5] == cAttributes 

If no files are found matching cDirSpec or if cDirSpec is an illegal path or file specification, 

DIRECTORY() returns an empty ({}) array. 

368.14.73 DISKSPACE() 

DISKSPACE([nDrive]) ⇒ nBytes 

nDrive 

is the number of the drive to query, where one is drive A, two 

is B, three is C, etc. The default is the current DOS drive if 

nDrive is omitted or specified as zero.


DISKSPACE() returns the number of bytes of empty space on the specified disk drive as an 

integer numeric value. 

368.14.74 DISPBOX() 

Display box 

DISPBOX(nTop, nLeft, nBottom, nRight, 

[cnBoxString], [cColorString]) ⇒ NIL 

nTop, nLeft, nBottom, nRight define the coordinates of the box. 

is a numeric or character expression that defines the border 

characters of the box. If specified as a numeric expression, a 

value of 1 displays a single-line box and a value of 2 displays 

cnBoxString 

a double-line box. All other numeric values display a singleline 

box. If cnBoxString is a character expression, it specifies 

the characters to be used in drawing the box. This is a string 

of eight border characters and a fill character. 

cColorString defines the display color of the box that is drawn. 

DISPBOX() is a screen function that draws a box at the specified display coordinates in the 

specified color. 

368.14.75 DISPOUT() 

Display out 

DISPOUT(exp, [cColorString]) ⇒ NIL 


cColorString is an optional argument that defines the display color of exp. 

cColorString is a character expression containing the standard color setting. 

DISPOUT() is a simple output function that writes the value of a single expression to the display 

at the current cursor position. This function ignores the SET DEVICE setting; output always goes 

to the screen. 

368.14.76 DOW() 

Day of week 

DOW(dDate) ⇒ nDay 

dDate is a date value to convert. 

DOW() returns the day of the week as a number between zero and seven. The first day of the 

week is one (Sunday) and the last day is seven (Saturday). If dDate is empty, DOW() returns 

zero.


368.14.77 DTOC() 

Date to character 

DTOC(dDate) ⇒ cDate 


DTOC() returns a character string representation of a date value. The return value is formatted in 

the current date format. A null date returns a string of spaces equal in length to the current date 

format. 

368.14.78 DTOS() 

Date to sort 

DTOS(dDate) ⇒ cDate 


DTOS() returns a character string eight characters long in the form, yyyymmdd. When dDate is 

a null date (CTOD("")), DTOS() returns a string of eight spaces. 

368.14.79 EMPTY() 

EMPTY(exp) ⇒ lEmpty 

exp is an expression of any data type. 

EMPTY() returns true (‘.T.’) if the expression results in an empty value; otherwise, it returns 

false (‘.F.’): 

Array {} 

Character/Memo 

Spaces, tabs, CR/LF, or "" 

Numeric 0 

Date CTOD("") 

Logical ‘.F.’ 

NIL NIL 

368.14.80 EOF() 

End of file 

EOF() ⇒ lBoundary 

EOF() returns true (‘.T.’) when an attempt is made to move the record pointer beyond the last 

logical record in a database file; otherwise, it returns false (‘.F.’). If there is no database file 

open in the current work area, EOF() returns false (‘.F.’). If the current database file contains 

no records, EOF() returns true (‘.T.’).


368.14.81 EVAL() 

Code block evaluation 

EVAL(bBlock, [BlockArg_list]) ⇒ LastBlockValue 

bBlock is the code block to evaluate. 

BlockArg_list 

is a list of arguments to send to the code block before it is 

evaluated. 

To execute or evaluate a code block, call EVAL() with the block value and any parameters. 

The parameters are supplied to the block when it is executed. Code blocks may be a series of 

expressions separated by commas. When a code block is evaluated, the returned value is the 

value of the last expression in the block. 

368.14.82 EXP() 

Exponent 

EXP(nExponent) ⇒ nAntilogarithm 

nExponent 

is the natural logarithm for which a numeric value is to be 

calculated. 

EXP() returns a numeric value that is equivalent to the value e raised to the specified power. 

368.14.83 FCLOSE() 

File close 

FCLOSE(nHandle) ⇒ lError 

nHandle 

is the file handle obtained previously from FOPEN() or 

FCREATE(). 

FCLOSE() is a low-level file function that closes binary files and forces the associated DOS 

buffers to be written to disk. If the operation fails, FCLOSE() returns false (‘.F.’). FERROR() 

can then be used to determine the reason for the failure. 

368.14.84 FCOUNT() 

Field count 

FCOUNT() ⇒ nFields 

FCOUNT() returns the number of fields in the database file in the active alias as an integer 

numeric value. If there is no database file open, FCOUNT() returns zero.


368.14.85 FCREATE() 

Field create 

FCREATE(cFile, [nAttribute]) ⇒ nHandle 

cFile 

nAttribute 

is the name of the file to create. If the file already exists, its 

length is truncated to zero without warning. 

is the binary file attribute, the default value is zero. 

nAttribute = 0 Normal (default) 

nAttribute = 1 Read-only 

nAttribute = 2 Hidden 

nAttribute = 4 System 

FCREATE() returns the DOS file handle number of the new binary file in the range of zero to 

65,535. If an error occurs, FCREATE() returns -1 and FERROR() is set to indicate an error code. 

368.14.86 FERASE() 

File erase 

FERASE(cFile) ⇒ nSuccess 

cFile 

is the name (with or without path) of the file to be deleted 

from disk. 

FERASE() is a file function that deletes a specified file from disk. FERASE() returns -1 if the 

operation fails and zero if it succeeds. 

368.14.87 FERROR() 

File error 

FERROR() ⇒ nErrorCode 

FERROR() returns the DOS error from the last file operation as an integer numeric value. If there 

is no error, FERROR() returns zero. 

nErrorCode value 

Meaning 

0 Successful 

2 File not found 

3 Path not found 

4 

Too many files open 

5 Access denied 

6 Invalid handle 

8 

Insufficient memory 

15 

Invalid drive specified 

19 Attempted to write to a write-protected disk 

21 

Drive not ready 

23 Data CRC error 

29 Write fault 

30 Read fault 

32 

Sharing violation 

33 Lock Violation


FERROR() is a low-level file function that indicates a DOS error after a file function is used. 

368.14.88 FIELDBLOCK() 

FIELDBLOCK(cFieldName) ⇒ bFieldBlock 

cFieldName 

is the name of the field to which the set-get block will refer. 

FIELDBLOCK() returns a code block that, when evaluated, sets (assigns) or gets (retrieves) the 

value of the given field. If cFieldName does not exist in the current work area, FIELDBLOCK() 

returns NIL. 

368.14.89 FIELDGET() 

FIELDGET(nField) ⇒ ValueField 

nField 

is the ordinal position of the field in the record structure for 

the current work area. 

FIELDGET() returns the value of the specified field. If nField does not correspond to the position 

of any field in the current database file, FIELDGET() returns NIL. 

368.14.90 FIELDNAME() 

FIELDNAME(nPosition) ⇒ cFieldName 

nPosition 

is the position of a field in the database file structure. 

FIELDNAME() returns the name of the specified field as a character string. If nPosition does 

not correspond to an existing field in the current database file or if no database file is open in the 

current work area, FIELDNAME() returns a null string (""). 

368.14.91 FIELDPOS() 

Field position 

FIELDPOS(cFieldName) ⇒ nFieldPos 

cFieldName 

is the name of a field in the current or specified work area. 

FIELDPOS() returns the position of the specified field within the list of fields associated with 

the current or specified work area. If the current work area has no field with the specified name, 

FIELDPOS() returns zero.


368.14.92 FIELDPUT() 

FIELDPUT(nField, expAssign) ⇒ ValueAssigned 

nField 

expAssign 

is the ordinal position of the field in the current database file. 

is the value to assign to the given field. The data type of this 

expression must match the data type of the designated field 

variable. 

FIELDPUT() is a database function that assigns expAssign to the field at ordinal position nField 

in the current work area. This function allows you to set the value of a field using its position 

within the database file structure rather than its field name. 

368.14.93 FIELDWBLOCK() 

Field work area block 

FIELDWBLOCK(cFieldName, nWorkArea) ⇒ bFieldWBlock 

cFieldName 

nWorkArea 

is the name of the field specified as a character string. 

is the work area number where the field resides specified as a 

numeric value. 

FIELDWBLOCK() returns a code block that, when evaluated, sets (assigns) or gets (retrieves) 

the value of cFieldName in the work area designated by nWorkArea. If cFieldName does not 

exist in the specified work area, FIELDWBLOCK() returns NIL. 

368.14.94 FILE() 

FILE(cFilespec) ⇒ lExists 

cFilespec 

is in the current default directory and path. It is a standard file 

specification that can include the wildcard characters * and ? 

as well as a drive and path reference. 

FILE() returns true (‘.T.’) if there is a match for any file matching the cFilespec pattern; otherwise, 

it returns false (‘.F.’). 

368.14.95 FLOCK() 

File lock 

FLOCK() ⇒ lSuccess 

FLOCK() tries to lock the active alias and returns true (‘.T.’) if it succeeds; otherwise, it returns 

false (‘.F.’).


368.14.96 FOPEN() 

File open 

FOPEN(cFile, [nMode]) ⇒ nHandle 

cFile 

nMode 

is the name of the file to open including the path if there is 

one. 

is the requested DOS open mode indicating how the opened 

file is to be accessed. The open mode is composed of the sum 

of two elements: the Open mode and the Sharing mode. 

Open mode: 

0 Open for reading (default) 

1 Open for writing 

2 Open for reading or writing 

Sharing mode: 

0 Compatibility mode (default) 

16 Exclusive use 

32 Prevent others from writing 

48 Prevent others from reading 

64 Allow others to read or write 

FOPEN() returns the file handle of the opened file in the range of zero to 65,535. If an error 

occurs, FOPEN() returns -1. 

368.14.97 FOUND() 

FOUND() ⇒ lSuccess 

FOUND() returns true (‘.T.’) if the last search command was successful; otherwise, it returns 


368.14.98 FREAD() 

File read 

FREAD(nHandle, @cBufferVar, nBytes) ⇒ nBytes 

is the file handle obtained from FOPEN(), FCREATE(), or 

nHandle 

predefined by DOS. 

is the name of an existing and initialized character variable 

used to store data read from the specified file. The length 

cBufferVar 

of this variable must be greater than or equal to nBytes. 

cBufferVar must be passed by reference and, therefore, must 

be prefaced by the pass-by-reference operator (@). 

nBytes is the number of bytes to read into the buffer. 

FREAD() tries to read nBytes of the binary file nHandle inside cBufferVar. It returns the number 

of bytes successfully read as an integer numeric value. A return value less than nBytes or 

zero indicates end of file or some other read error.


368.14.99 FREADSTR() 

File read string 

FREADSTR(nHandle, nBytes) ⇒ cString 

nHandle 

nBytes 



is the number of bytes to read, beginning at the current DOS 

file pointer position. 

FREADSTR() returns a character string up to 65,535 (64K) bytes. A null return value ("") indicates 

an error or end of file. FREADSTR() is a low-level file function that reads characters from 

an open binary file beginning with the current DOS file pointer position. Characters are read up 

to nBytes or until a null character (CHR(0)) is encountered. All characters are read including 

control characters except for CHR(0). The file pointer is then moved forward nBytes. If nBytes 

is greater than the number of bytes from the pointer position to the end of the file, the file pointer 

is positioned to the last byte in the file. 

368.14.100 FRENAME() 

File rename 

FRENAME(cOldFile, cNewFile) ⇒ nSuccess 

cOldFile 

cNewFile 

is the name of the file to rename, including the file extension. 

A drive letter and/or path name may also be included as part 

of the filename. 

is the new name of the file, including the file extension. A 

drive letter and/or path name may also be included as part of 

the name. 

FRENAME() returns -1 if the operation fails and zero if it succeeds. 

368.14.101 FSEEK() 

File seek 

FSEEK(nHandle, nOffset, [nOrigin]) ⇒ nPosition 


nHandle 


is the number of bytes to move the file pointer from the position 

defined by nOrigin. It can be a positive or negative 

nOffset 

number. A positive number moves the pointer forward, and 

a negative number moves the pointer backward in the file. 

defines the starting location of the file pointer before FSEEK() 

is executed. The default value is zero, representing the begin- 

nOrigin 

ning of file. If nOrigin is the end of file, nOffset must be zero 

or negative. 

nOrigin == 0 Seek from beginning of file 

nOrigin == 1 Seek from the current pointer position 

nOrigin == 2 Seek from end of file


FSEEK() returns the new position of the file pointer relative to the beginning of file (position 

0) as an integer numeric value. This value is without regard to the original position of the file 

pointer. FSEEK() is a low-level file function that moves the file pointer forward or backward 

in an open binary file without actually reading the contents of the specified file. The beginning 

position and offset are specified as function arguments, and the new file position is returned. 

368.14.102 FWRITE() 

File write 

FWRITE(nHandle, cBuffer, [nBytes]) ⇒ nBytesWritten 

nHandle 



cBuffer is the character string to write to the specified file. 

nBytes 

indicates the number of bytes to write beginning at the current 

file pointer position. If omitted, the entire content of cBuffer 

is written. 

FWRITE() returns the number of bytes written as an integer numeric value. If the value returned 

is equal to nBytes, the operation was successful. If the return value is less than nBytes or zero, 

either the disk is full or another error has occurred. 

368.14.103 GETENV() 

Get environment 

GETENV(cEnvironmentVariable) ⇒ cString 

cEnvironmentVariable 

is the name of the DOS environment variable. When specifying 

this argument, you can use any combination of upper and 

lowercase letters; GETENV() is not case- sensitive. 

GETENV() returns the contents of the specified DOS environment variable as a character string. 

If the variable cannot be found, GETENV() returns a null string (""). 

368.14.104 HARDCR() 

Hard carriage return 

HARDCR(cString) ⇒ cConvertedString 

cString is the character string or memo field to convert. 

HARDCR() is a memo function that replaces all soft carriage returns (CHR(141)) with hard carriage 

returns (CHR(13)). It is used to display long character strings and memo fields containing 

soft carriage returns with console commands.


368.14.105 HEADER() 

HEADER() ⇒ nBytes 

HEADER() returns the number of bytes in the header of the current database file as an integer 

numeric value. If no database file is in use, HEADER() returns a zero (0). 

368.14.106 I2BIN() 

Integer to binary 

I2BIN(nInteger) ⇒ cBinaryInteger 

nInteger 

is an integer numeric value to convert. Decimal digits are truncated. 

I2BIN() returns a two-byte character string containing a 16-bit binary integer. 

368.14.107 IF() 

[I]IF(lCondition, expTrue, expFalse) ⇒ Value 

lCondition 

expTrue 

expFalse 

is a logical expression to be evaluated. 

is the value, a condition-expression, of any data type, returned 

if lCondition is true (‘.T.’). 

is the value, of any date type, returned if lCondition is false 

(‘.F.’). This argument need not be the same data type as 

expTrue. 

IF() returns the evaluation of expTrue if lCondition evaluates to true (‘.T.’) and expFalse if it 

evaluates to false (‘.F.’). 

368.14.108 INDEXEXT() 

Index extention 

INDEXEXT() ⇒ cExtension 

INDEXEXT() returns the default index file extension by determining which database driver is 

currently linked. 

368.14.109 INDEXKEY() 

INDEXKEY(nOrder) ⇒ cKeyExp 

nOrder 

is the ordinal position of the index in the list of index files 

opened by the last USE...INDEX or SET INDEX TO command 

for the current work area. A zero value specifies the 

controlling index, without regard to its actual position in the 

list.


INDEXKEY() returns the key expression of the specified index as a character string. If there is 

no corresponding index or if no database file is open, INDEXKEY() returns a null string (""). 

368.14.110 INDEXORD() 

Index order 

INDEXORD() ⇒ nOrder 

INDEXORD() returns an integer numeric value. The value returned is equal to the position of the 

controlling index in the list of open indexes for the current work area. A value of zero indicates 

that there is no controlling index and records are being accessed in natural order. If no database 

file is open, INDEXORD() will also return a zero. 

368.14.111 INKEY() 

Input key 

INKEY([nSeconds]) ⇒ nInkeyCode 

nSeconds 

specifies the number of seconds INKEY() waits for a keypress. 

You can specify the value in increments as small as 

one-tenth of a second. Specifying zero halts the program until 

a key is pressed. If nSeconds is omitted, INKEY() does not 

wait for a keypress. 

INKEY() returns an integer numeric value from -39 to 386, identifying the key extracted from 

the keyboard buffer. If the keyboard buffer is empty, INKEY() returns zero. INKEY() returns 

values for all ASCII characters, function, Alt+function, Ctrl+function, Alt+letter, and Ctrl+letter 

key combinations. 

nInkeyCode value Key or key combination 

5 [ Up arrow ], [ Ctrl ]+E 

24 [ Down arrow ], [ Ctrl ]+X 

19 [ Left arrow ], [ Ctrl ]+S 

4 [ Right arrow ], [ Ctrl ]+D 

1 [ Home ], [ Ctrl ]+A 

6 [ End ], [ Ctrl ]+F 

18 [ PgUp ], [ Ctrl ]+R 

3 [ PgDn ], [ Ctrl ]+C 

397 

[ Ctrl ]+[ Up arrow ] 

401 

[ Ctrl ]+[ Down arrow ] 

26 [ Ctrl ]+[ Left arrow ], [ Ctrl ]+Z 

2 [ Ctrl ]+[ Right arrow ], [ Ctrl ]+B 

29 

[ Ctrl ]+[ Home ] 

23 [ Ctrl ]+[ End ], [ Ctrl ]+W 

31 

[ Ctrl ]+[ PgUp ], [ Ctrl ]+Hyphen 

30 [ Ctrl ]+[ PgDn ], [ Ctrl ]+^ 

408 

[ Alt ]+[ Up arrow ] 

416 

[ Alt ]+[ Down arrow ] 

411 

[ Alt ]+[ Left arrow ] 

413 

[ Alt ]+[ Right arrow ] 

407 

[ Alt ]+[ Home ]



415 

[ Alt ]+[ End ] 

409 

[ Alt ]+[ PgUp ] 

417 

[ Alt ]+[ PgDn ] 

13 [ Enter ], [ Ctrl ]+M 

32 

Space bar 

27 Esc 

10 

[ Ctrl ]+[ Enter ] 

379 [ Ctrl ]+Print Screen 

309 [ Ctrl ]+? 

284 

[ Alt ]+[ Enter ] 

387 

[ Alt ]+Equals 

257 [ Alt ]+Esc 

422 

Keypad [ Alt ]+[ Enter ] 

399 Keypad [ Ctrl ]+5 

405 

Keypad [ Ctrl ]+/ 

406 

Keypad [ Ctrl ]+* 

398 Keypad [ Ctrl ]+- 

400 

Keypad [ Ctrl ]++ 

5 

Keypad [ Alt ]+5 

420 

Keypad [ Alt ]+/ 

311 

Keypad [ Alt ]+* 

330 

Keypad [ Alt ]+- 

334 

Keypad [ Alt ]++ 

22 [ Ins ], [ Ctrl ]+V 

7 [ Del ], [ Ctrl ]+G 

8 [ Backspace ], [ Ctrl ]+H 

9 [ Tab ], [ Ctrl ]+I 

271 

[ Shift ]+[ Tab ] 

402 

[ Ctrl ]+[ Ins ] 

403 

[ Ctrl ]+[ Del ] 

127 

[ Ctrl ]+[ Backspace ] 

404 

[ Ctrl ]+[ Tab ] 

418 

[ Alt ]+[ Ins ] 

419 

[ Alt ]+[ Del ] 

270 

[ Alt ]+[ Backspace ] 

421 

[ Alt ]+[ Tab ] 

1 [ Ctrl ]+A, [ Home ] 

2 [ Ctrl ]+B, [ Ctrl ]+[ Right arrow ] 

3 [ Ctrl ]+C, [ PgDn ], [ Ctrl ]+[ ScrollLock ] 

4 [ Ctrl ]+D, [ Right arrow ] 

5 [ Ctrl ]+E, [ Up arrow ] 

6 [ Ctrl ]+F, [ End ] 

7 [ Ctrl ]+G, [ Del ] 

8 [ Ctrl ]+H, [ Backspace ] 

9 [ Ctrl ]+I, [ Tab ] 

10 [ Ctrl ]+J 

11 [ Ctrl ]+K 

12 [ Ctrl ]+L 

13 [ Ctrl ]+M, Return 

14 [ Ctrl ]+N 

15 [ Ctrl ]+O 

16 [ Ctrl ]+P 

17 [ Ctrl ]+Q



18 [ Ctrl ]+R, [ PgUp ] 

19 [ Ctrl ]+S, [ Left arrow ] 

20 [ Ctrl ]+T 

21 [ Ctrl ]+U 

22 [ Ctrl ]+V, [ Ins ] 

23 [ Ctrl ]+W, [ Ctrl ]+[ End ] 

24 [ Ctrl ]+X, [ Down arrow ] 

25 [ Ctrl ]+Y 

26 [ Ctrl ]+Z, [ Ctrl ]+[ Left arrow ] 

286 [ Alt ]+A 

304 [ Alt ]+B 

302 [ Alt ]+C 

288 [ Alt ]+D 

274 [ Alt ]+E 

289 [ Alt ]+F 

290 [ Alt ]+G 

291 [ Alt ]+H 

279 [ Alt ]+I 

292 [ Alt ]+J 

293 [ Alt ]+K 

294 [ Alt ]+L 

306 [ Alt ]+M 

305 [ Alt ]+N 

280 [ Alt ]+O 

281 [ Alt ]+P 

272 [ Alt ]+Q 

275 [ Alt ]+R 

287 [ Alt ]+S 

276 [ Alt ]+T 

278 [ Alt ]+U 

303 [ Alt ]+V 

273 [ Alt ]+W 

301 [ Alt ]+X 

277 [ Alt ]+Y 

300 [ Alt ]+Z 

376 [ Alt ]+1 

377 [ Alt ]+2 

378 [ Alt ]+3 

379 [ Alt ]+4 

380 [ Alt ]+5 

381 [ Alt ]+6 

382 [ Alt ]+7 

383 [ Alt ]+8 

384 [ Alt ]+9 

385 [ Alt ]+0 

28 F1, [ Ctrl ]+[ Backslash ] 

-1 F2 

-2 F3 

-3 F4 

-4 F5 

-5 F6 

-6 F7 

-7 F8



-8 F9 

-9 F10 

-40 F11 

-41 F12 

-20 [ Ctrl ]+F1 

-21 [ Ctrl ]+F2 

-22 [ Ctrl ]+F4 

-23 [ Ctrl ]+F3 

-24 [ Ctrl ]+F5 

-25 [ Ctrl ]+F6 

-26 [ Ctrl ]+F7 

-27 [ Ctrl ]+F8 

-28 [ Ctrl ]+F9 

-29 [ Ctrl ]+F10 

-44 [ Ctrl ]+F11 

-45 [ Ctrl ]+F12 

-30 [ Alt ]+F1 

-31 [ Alt ]+F2 

-32 [ Alt ]+F3 

-33 [ Alt ]+F4 

-34 [ Alt ]+F5 

-35 [ Alt ]+F6 

-36 [ Alt ]+F7 

-37 [ Alt ]+F8 

-38 [ Alt ]+F9 

-39 [ Alt ]+F10 

-46 [ Alt ]+F11 

-47 [ Alt ]+F12 

-10 [ Shift ]+F1 

-11 [ Shift ]+F2 

-12 [ Shift ]+F3 

-13 [ Shift ]+F4 

-14 [ Shift ]+F5 

-15 [ Shift ]+F6 

-16 [ Shift ]+F7 

-17 [ Shift ]+F8 

-18 [ Shift ]+F9 

-19 [ Shift ]+F10 

-42 [ Shift ]+F11 

-43 [ Shift ]+F12 

368.14.112 INT() 

Integer 

INT(nExp) ⇒ nInteger 

nExp is a numeric expression to convert to an integer. 

INT() is a numeric function that converts a numeric value to an integer by truncating all digits 

to the right of the decimal point. INT() is useful in operations where the decimal portion of a


number is not needed. 

368.14.113 ISALPHA() 

ISALPHA(cString) ⇒ lBoolean 

cString is the character string to examine. 

ISALPHA() returns true (‘.T.’) if the first character in cString is alphabetic; otherwise, it returns 


368.14.114 ISCOLOR() 

ISCOLOR() | ISCOLOUR() ⇒ lBoolean 

ISCOLOR() returns true (‘.T.’) if there is a color graphics card installed; otherwise, it returns 


368.14.115 ISDIGIT() 

ISDIGIT(cString) ⇒ lBoolean 


ISDIGIT() returns true (‘.T.’) if the first character of the character string is a digit between zero 

and nine; otherwise, it returns false (‘.F.’). 

368.14.116 ISLOWER() 

ISLOWER(cString) ⇒ lBoolean 


ISLOWER() returns true (‘.T.’) if the first character of the character string is a lowercase letter; 

otherwise, it returns false (‘.F.’). 

368.14.117 ISPRINTER() 

ISPRINTER() ⇒ lReady 

ISPRINTER() returns true (‘.T.’) if ‘LPT1:’ is ready; otherwise, it returns false (‘.F.’).


368.14.118 ISUPPER() 

ISUPPER(cString) ⇒ lBoolean 


ISUPPER() returns true (‘.T.’) if the first character is an uppercase letter; otherwise, it returns 


368.14.119 L2BIN() 

Long to binary 

L2BIN(nExp) ⇒ cBinaryInteger 

nExp is the numeric value to convert. Decimal digits are truncated. 

L2BIN() returns a four-byte character string formatted as a 32- bit binary integer. 

368.14.120 LASTKEY() 

LASTKEY() ⇒ nInkeyCode 

LASTKEY() is a keyboard function that reports the INKEY() value of the last key fetched from 

the keyboard buffer by the INKEY() function, or a wait state. LASTKEY() retains its current 

value until another key is fetched from the keyboard buffer. 

368.14.121 LASTREC() 

Last record 

LASTREC() ⇒ nRecords 

LASTREC() returns the number of physical records in the active alias as an integer numeric 

value. 

368.14.122 LEFT() 

LEFT(cString, nCount) ⇒ cSubString 

cString is a character string from which to extract characters. 

nCount is the number of characters to extract. 

LEFT() returns the leftmost nCount characters of cString as a character string. If nCount is 

negative or zero, LEFT() returns a null string (""). If nCount is larger than the length of the 

character string, LEFT() returns the entire string.


368.14.123 LEN() 

Length 

LEN(cString | aTarget) ⇒ nCount 

cString is the character string to count. 

aTarget is the array to count. 

LEN() returns the length of a character string or the number of elements in an array as an integer 

numeric value. 

368.14.124 LOG() 

LOG(nExp) ⇒ nNaturalLog 

nExp 

is a numeric value greater than zero to convert to its natural 

logarithm. 

LOG() returns the natural logarithm as a numeric value. If nExp is less than or equal to zero, 

LOG() returns a numeric overflow (displayed as a row of asterisks). 

368.14.125 LOWER() 

LOWER(cString) ⇒ cLowerString 

cString is a character string to convert to lowercase. 

LOWER() returns a copy of cString with all alphabetic characters converted to lowercase. 

368.14.126 LTRIM() 

Left trim 

LTRIM(cString) ⇒ cTrimString 

cString is the character string to copy without leading spaces. 

LTRIM() returns a copy of cString with the leading spaces removed. 

368.14.127 LUPDATE() 

Last update 

LUPDATE() ⇒ dModification 

LUPDATE() returns the date of last change to the open database file in the current work area.


368.14.128 MAX() 

MAX(nExp1, nExp2) ⇒ nLarger 

MAX(dExp1, dExp2) ⇒ dLarger 

nExp1, nExp2 are the numeric values to compare. 

dExp1, dExp2 are the date values to compare. 

MAX() returns the larger of the two arguments. The value returned is the same type as the arguments. 

368.14.129 MAXCOL() 

Max column 

MAXCOL() ⇒ nColumn 

MAXCOL() returns the column number of the rightmost visible column for display purposes. 

368.14.130 MAXROW() 

MAXROW() ⇒ nRow 

MAXROW() returns the row number of the bottommost visible row for display purposes. 

368.14.131 MEMOEDIT() 

MEMOEDIT([cString], 

[nTop], [nLeft], 

[nBottom], [nRight], 

[lEditMode], 

[cUserFunction], 

[nLineLength], 

[nTabSize], 

[nTextBufferRow], 

[nTextBufferColumn], 

[nWindowRow], 

[nWindowColumn]) ⇒ cTextBuffer 

cString 

nTop, nLeft, nBottom, nRight 

lEditMode 

cUserFunction 

nLineLength 

is the character string or memo field to copy to the MEM- 

OEDIT() text buffer. 

are window coordinates. The default coordinates are 0, 0, 

MAXROW(), and MAXCOL(). 

determines whether the text buffer can be edited or merely 

displayed. If not specified, the default value is true (‘.T.’). 

is the name of a user-defined function that executes when the 

user presses a key not recognized by MEMOEDIT() and when 

no keys are pending in the keyboard buffer. 

determines the length of lines displayed in the MEMOEDIT() 

window. If a line is greater than nLineLength, it is word 

wrapped to the next line in the MEMOEDIT() window. The 

default line length is (nRight - nLeft).


nTabSize 

nTextBufferRow, 

nTextBufferColumn 

nWindowRow, nWindowColumn 

determines the size of a tab character to insert when the user 

presses Tab. The default is four. 

define the display position of the cursor within the text buffer 

when MEMOEDIT() is invoked. nTextBufferRow begins 

with one and nTextBufferColumn begins with zero. Default 

is the beginning of MEMOEDIT() window. 

define the initial position of the cursor within the MEM- 

OEDIT() window. Row and column positions begin with zero. 

If these arguments are not specified, the initial window position 

is row zero and the current cursor column position. 

MEMOEDIT() is a user interface and general purpose text editing function that edits memo fields 

and long character strings. Editing occurs within a specified window region placed anywhere on 

the screen. 

[ Uparrow ]/[ Ctrl ]+E Move up one line 

[ Dnarrow ]/[ Ctrl ]+X Move down one line 

[ Leftarrow ]/[ Ctrl ]+S Move left one character 

[ Rightarrow ]/[ Ctrl ]+D Move right one character 

[ Ctrl ]-[ Leftarrow ]/[ Ctrl ]+A Move left one word 

[ Ctrl ]-[ Rightarrow ]/[ Ctrl ]+F Move right one word 

[ Home ] Move to beginning of current line 

[ End ] Move to end of current line 

[ Ctrl ]+[ Home ] Move to beginning of current window 

[ Ctrl ]+[ End ] Move to end of current window 

[ PgUp ] Move to previous edit window 

[ PgDn ] Move to next edit window 

[ Ctrl ]+[ PgUp ] Move to beginning of memo 

[ Ctrl ]+[ PgDn ] Move to end of memo 

[ Return ] Move to beginning of next line 

[ Delete ] Delete character at cursor 

[ Backspace ] Delete character to left of cursor 

[ Tab ] Insert tab character or spaces 

Printable characters Insert character 

[ Ctrl ]+Y Delete the current line 

[ Ctrl ]+T Delete word right 

[ Ctrl ]+B Reform paragraph 

[ Ctrl ]+V/[ Ins ] Toggle insert mode 

[ Ctrl ]+W Finish editing with save 

[ Esc ] Abort edit and return original 

368.14.132 MEMOLINE() 

MEMOLINE(cString, 

[nLineLength], 

[nLineNumber], 

[nTabSize], 

[lWrap]) ⇒ cLine 

cString 

nLineLength 

is the memo field or character string from which to extract a 

line of text. 

specifies the number of characters per line and can be between 

four and 254 . If not specified, the default line length is 79.


nLineNumber 

is the line number to extract. If not specified, the default value 

is one. 

nTabSize defines the tab size. If not specified, the default value is four. 

lWrap 

toggles word wrap on and off. Specifying true (‘.T.’) toggles 

word wrap on; false (‘.F.’) toggles it off. If not specified, the 

default value is true (‘.T.’). 

MEMOLINE() returns the line of text specified by nLineNumber in cString as a character string. 

If the line has fewer characters than the indicated length, the return value is padded with blanks. 

If the line number is greater than the total number of lines in cString, MEMOLINE() returns a 

null string (""). If lWrap is true (‘.T.’) and the indicated line length breaks the line in the middle 

of a word, that word is not included as part of the return value but shows up at the beginning of 

the next line extracted with MEMOLINE(). If lWrap is false (‘.F.’), MEMOLINE() returns only 

the number of characters specified by the line length. The next line extracted by MEMOLINE() 

begins with the character following the next hard carriage return, and all intervening characters 

are not processed. 

368.14.133 MEMOREAD() 

MEMOREAD(cFile) ⇒ cString 

cFile 

is the name of the file to read from disk. It must include an 

extension if there is one, and can optionally include a path. 

MEMOREAD() returns the contents of a text file as a character string. 

368.14.134 MEMORY() 

MEMORY(nExp) ⇒ nKbytes 

nExp 

is a numeric value that determines the type of value MEM- 

ORY() returns. 

MEMORY() returns an integer numeric value representing the amount of memory available. 

MEMORY(0) Estimated total space available for character values 

MEMORY(1) Largest contiguous block available for character values 

MEMORY(2) Area available for RUN commands 

368.14.135 MEMOTRAN() 

Memo translate 

MEMOTRAN(cString, 

[cReplaceHardCR], 

[cReplaceSoftCR]) ⇒ cNewString 

cString is the character string or memo field to search. 

cReplaceHardCR 

is the character to replace a hard carriage return/linefeed pair 

with. If not specified, the default value is a semicolon (;).


cReplaceSoftCR 

is the character to replace a soft carriage return/linefeed pair 

with. If not specified, the default value is a space. 

MEMOTRAN() returns a copy of cString with the specified carriage return/linefeed pairs replaced. 

368.14.136 MEMOWRIT() 

Memo write 

MEMOWRIT(cFile, cString) ⇒ lSuccess 

cFile 

is the name of the target disk file including the file extension 

and optional path and drive designator. 

cString is the character string or memo field to write to cFile. 

MEMOWRIT() is a memo function that writes a character string or memo field to a disk file. 

If a path is not specified, MEMOWRIT() writes cFile to the current DOS directory and not the 

current DEFAULT directory. If cFile already exists, it is overwritten. MEMOWRIT() returns true 

(‘.T.’) if the writing operation is successful; otherwise, it returns false (‘.F.’). 

368.14.137 MEMVARBLOCK() 

MEMVARBLOCK(cMemvarName) ⇒ bMemvarBlock 

cMemvarName 

is the name of the variable referred to by the set-get block, 

specified as a character string. 

MEMVARBLOCK() returns a code block that when evaluated sets (assigns) or gets (retrieves) 

the value of the given memory variable. If cMemvarName does not exist, MEMVARBLOCK() 

returns NIL. 

368.14.138 MIN() 

MIN(nExp1, nExp2) ⇒ nSmaller 

MIN(dExp1, dExp2) ⇒ dSmaller 

nExp1, nExp2 are the numeric values to compare. 

dExp1, dExp2 are the date values to compare. 

MIN() returns the smaller of the two arguments. The value returned is the same data type as the 

arguments.


368.14.139 MLCOUNT() 

Memo line count 

MLCOUNT(cString, [nLineLength], 

[nTabSize], [lWrap]) ⇒ nLines 

cString is the character string or memo field to count. 

nLineLength 

specifies the number of characters per line and can range from 

four to 254 . If not specified, the default line length is 79. 

nTabSize defines the tab size. If not specified, the default value is four. 


lWrap 

word wrap on; false (‘.F.’) toggles it off. If not specified, the 

default value is true (‘.T.’). 

MLCOUNT() returns the number of lines in cString depending on the nLineLength, the 

nTabSize, and whether word wrapping is on or off. 

368.14.140 MLCTOPOS() 

Memo line column to position 

MLCTOPOS(cText, nWidth, nLine, 

nCol, [nTabSize], [lWrap]) ⇒ nPosition 

cText 

nWidth 

nLine 

nCol 

nTabSize 

lWrap 

is the text string to scan. 

is the line length formatting width. 

is the line number counting from 1. 

is the column number counting from 0. 

is the number of columns between tab stops. If not specified, 

the default is 4. 

is the word wrap flag. If not specified, the default is true 

(‘.T.’). 

MLCTOPOS() returns the byte position within cText counting from 1. 

368.14.141 MLPOS() 

Memo line position 

MLPOS(cString, nLineLength, 

nLine, [nTabSize], [lWrap]) ⇒ nPosition 

cString is a character string or memo field. 

nLineLength specifies the number of characters per line. 

nLine 

specifies the line number. 

nTabSize defines the tab size. The default is four. 


lWrap 

word wrap on, and false (‘.F.’) toggles it off. The default is 

true (‘.T.’). 

MLPOS() returns the character position of nLine in cString as an integer numeric value. If 

nLine is greater than the number of lines in cString, MLPOS() returns the length of cString.


368.14.142 MONTH() 

MONTH(dDate) ⇒ nMonth 


MONTH() returns an integer numeric value in the range of zero to 12. Specifying a null date 

(CTOD("")) returns zero. 

368.14.143 MPOSTOLC() 

Memo position to line column 

MPOSTOLC(cText, nWidth, nPos, 

[nTabSize], [lWrap]) ⇒ aLineColumn 

cText 

nWidth 

nPos 

nTabSize 

lWrap 

is a text string. 

is the length of the formatted line. 

is the byte position within text counting from one. 

is the number of columns between tab stops. If not specified, 

the default is four. 

is the word wrap flag. If not specified, the default is true 

(‘.T.’). 

MPOSTOLC() returns an array containing the line and the column values for the specified byte 

position, nPos. MPOSTOLC() is a memo function that determines the formatted line and column 

corresponding to a particular byte position within cText. Note that the line number returned is 

one-relative, the column number is zero-relative. This is compatible with MEMOEDIT(). nPos 

is one-relative, compatible with AT(), RAT(), and other string functions. 

368.14.144 NETERR() 

Net error 

NETERR([lNewError]) ⇒ lError 

lNewError 

if specified sets the value returned by NETERR() to the specified 

status. lNewError can be either true (‘.T.’) or false 

(‘.F.’). Setting NETERR() to a specified value allows the 

runtime error handler to control the way certain file errors are 

handled. 

NETERR() returns true (‘.T.’) if a USE or APPEND BLANK fails. The initial value of 

NETERR() is false (‘.F.’). If the current process is not running under a network operating system, 

NETERR() always returns false (‘.F.’).


368.14.145 NETNAME() 

NETNAME() ⇒ cWorkstationName 

NETNAME() returns the workstation identification as a character string up to 15 characters in 

length. If the workstation identification was never set or the application is not operating under 

the IBM PC Network, it returns a null string (""). 

368.14.146 NEXTKEY() 

NEXTKEY() ⇒ nInkeyCode 

NEXTKEY() returns an integer numeric value ranging from -39 to 386. If the keyboard buffer 

is empty, NEXTKEY() returns zero. If SET TYPEAHEAD is zero, NEXTKEY() always returns 

zero. NEXTKEY() is like the INKEY() function, but differs in one fundamental respect. 

INKEY() removes the pending key from the keyboard buffer and updates LASTKEY() with the 

value of the key. NEXTKEY(), by contrast, reads, but does not remove the key from the keyboard 

buffer and does not update LASTKEY(). 

368.14.147 NOSNOW() 

NOSNOW(lToggle) ⇒ NIL 

lToggle 

NOSNOW() is used to suppress snow on old CGA monitors. 

368.14.148 ORDBAGEXT() 

ORDBAGEXT() ⇒ cBagExt 

is a logical value that toggles the current state of snow suppression. 

A value of true (‘.T.’) enables the snow suppression 

on, while a value of false (‘.F.’) disables snow suppression. 

ORDBAGEXT() returns a character expression that is the default Order Bag extension of the 

current work area. cBagExt is determined by the RDD active in the current work area. 

368.14.149 ORDBAGNAME() 

ORDBAGNAME(nOrder | cOrderName) ⇒ cOrderBagName 

nOrder 

cOrderName 

is an integer that identifies the position in the Order List of the 

target Order whose Order Bag name is sought. 

is a character string that represents the name of the target Order 

whose Order Bag name is sought. 

ORDBAGNAME() returns a character string, the Order Bag name of the specific Order.


368.14.150 ORDCREATE() 

ORDCREATE(cOrderBagName,[cOrderName], cExpKey, [bExpKey], 

[lUnique]) ⇒ NIL 

cOrderBagName is the name of a disk file containing one or more Orders. 

cOrderName is the name of the Order to be created. 

is an expression that returns the key value to place in the Order 

cExpKey 

for each record in the current work area. The maximum length 

of the index key expression is determined by the database 

driver. 

bExpKey 

is a code block that evaluates to a key value that is placed in 

the Order for each record in the current work area. 

lUnique 

specifies whether a unique Order is to be created. Default is 

the current global _SET_UNIQUE setting. 

ORDCREATE() is an Order management function that creates an Order in the current work area. 

It works like DBCREATEINDEX() except that it lets you create Orders in RDDs that recognize 

multiple Order Bags. 

368.14.151 ORDDESTROY() 

ORDDESTROY(cOrderName [, cOrderBagName ]) ⇒ NIL 

cOrderName 

is the name of the Order to be removed from the current or 

specified work area. 


ORDDESTROY() is an Order management function that removes a specified Order from 

multiple-Order Bags. ORDDESTROY() is not supported for DBFNDX and DBFNTX. 

368.14.152 ORDFOR() 

ORDFOR(cOrderName | nOrder [, cOrderBagName]) ⇒ cForExp 

cOrderName 

is the name of the target Order, whose cForExp is sought. 

nOrder 


target Order whose cForExp is sought. 

cOrderBagName is the name of an Order Bag containing one or more Orders. 

ORDFOR() returns a character expression, cForExp, that represents the FOR condition of the 

specified Order. If the Order was not created using the FOR clause the return value will be an 

empty string (""). If the database driver does not support the FOR condition, it may either return 

an empty string ("") or raise an "unsupported function" error, depending on the driver.


368.14.153 ORDKEY() 

ORDKEY(cOrderName | nOrder [, cOrderBagName]) ⇒ cExpKey 

cOrderName 

is the name of an Order, a logical ordering of a database. 

nOrder 


target Order whose cExpKey is sought. 


ORDKEY() is an Order management function that returns a character expression, cExpKey, that 

represents the key expression of the specified Order. 

368.14.154 ORDLISTADD() 

ORDLISTADD(cOrderBagName [, cOrderName]) ⇒ NIL 


the name of the specific Order from the Order Bag to be added 

to the Order List of the current work area. If you do not spec- 

cOrderName 

ify cOrderName, all orders in the Order Bag are added to the 

Order List of the current work area. 

ORDLISTADD() is an Order management function that adds the contents of an Order Bag , or 

a single Order in an Order Bag, to the Order List. Any Orders already associated with the work 

area continue to be active. If the newly opened Order Bag contains the only Order associated 

with the work area, it becomes the controlling Order; otherwise, the controlling Order remains 

unchanged. 

368.14.155 ORDLISTCLEAR() 

ORDLISTCLEAR() ⇒ NIL 

ORDLISTCLEAR() is an Order management function that removes all Orders from the Order 

List for the current work area. 

368.14.156 ORDLISTREBUILD() 

ORDLISTREBUILD() ⇒ NIL 

ORDLISTREBUILD() is an Order management function that rebuilds all the orders in the current 

Order List. 

368.14.157 ORDNAME() 

ORDNAME(nOrder[,cOrderBagName]) ⇒ cOrderName 

nOrder 


target Order whose database name is sought. 

cOrderBagName is the name of a disk file containing one or more Orders.


ORDNAME() returns the name of the specified Order in the current Order List or the specified 

Order Bag if opened in the Current Order list. 

368.14.158 ORDNUMBER() 

ORDNUMBER(cOrderName [, cOrderBagName]) ⇒ nOrderNo 

cOrderName 

the name of the specific Order whose position in the Order 

List is sought. 


ORDNUMBER() returns nOrderNo, an integer that represents the position of the specified Order 

in the Order List. 

368.14.159 ORDSETFOCUS() 

ORDSETFOCUS([cOrderName | nOrder] [,cOrderBagName]) 

⇒ cPrevOrderNameInFocus 

cOrderName 

is the name of the selected Order, a logical ordering of a 

database. 

nOrder 

is a number representing the position in the Order List of the 

selected Order. 


ORDSETFOCUS() is an Order management function that returns the Order Name of the previous 

controlling Order and optionally sets the focus to an new Order. 

368.14.160 OS() 

OS() ⇒ cOsName 

OS() returns the operating system name as a character string. 

368.14.161 OUTERR() 

Output error 

OUTERR(exp_list) ⇒ NIL 

exp_list 

is a list of values to display and can consist of any combination 

of data types including memo. 

OUTERR() is identical to OUTSTD() except that it writes to the standard error device rather 

than the standard output device. Output sent to the standard error device bypasses the console 

and output devices as well as any DOS redirection. It is typically used to log error messages in a 

manner that will not interfere with the standard screen or printer output.


368.14.162 OUTSTD() 

Output standard 

OUTSTD(exp_list) ⇒ NIL 

exp_list 

is a list of values to display and can consist of any combination 

of data types including memo. 

OUTSTD() is a simple output function similar to QOUT(), except that it writes to the STDOUT 

device (instead of to the console output stream). 

368.14.163 PAD?() 

PADL(exp, nLength, [cFillChar]) ⇒ cPaddedString 

PADC(exp, nLength, [cFillChar]) ⇒ cPaddedString 

PADR(exp, nLength, [cFillChar]) ⇒ cPaddedString 

exp 

is a character, numeric, or date value to pad with a fill character. 

nLength is the length of the character string to return. 

cFillChar 

is the character to pad exp with. If not specified, the default is 

a space character. 

PADC(), PADL(), and PADR() are character functions that pad character, date, and numeric 

values with a fill character to create a new character string of a specified length. PADC() centers 

exp within nLength adding fill characters to the left and right sides; PADL() adds fill characters 

on the left side; and PADR() adds fill characters on the right side. 

368.14.164 PCOL() 

Printed column 

PCOL() ⇒ nColumn 

PCOL() returns an integer numeric value representing the last printed column position, plus one. 

The beginning column position is zero. 

368.14.165 PROW() 

Printed row 

PROW() ⇒ nRow 

PROW() returns an integer numeric value that represents the number of the current line sent to 

the printer. The beginning row position is zero.


368.14.166 QOUT() 

QOUT([exp_list]) ⇒ NIL 

QQOUT([exp_list]) ⇒ NIL 

exp_list 

is a comma-separated list of expressions (of any data type 

other than array or block) to display to the console. If no argument 

is specified and QOUT() is specified, a carriage return/linefeed 

pair is displayed. If QQOUT() is specified without 

arguments, nothing displays. 

QOUT() and QQOUT() are console functions. They display the results of one or more expressions 

to the console. QOUT() outputs carriage return and linefeed characters before displaying 

the results of exp_list. QQOUT() displays the results of exp_list at the current ROW() and COL() 

position. When QOUT() and QQOUT() display to the console, ROW() and COL() are updated. 

368.14.167 RAT() 

Right at 

RAT(cSearch, cTarget) ⇒ nPosition 

cSearch 

is the character string to locate. 

cTarget is the character string to search. 

RAT() returns the position of cSearch within cTarget as an integer numeric value, starting the 

search from the right. If cSearch is not found, RAT() returns zero. 

368.14.168 RDDLIST() 

RDDLIST([nRDDType]) ⇒ aRDDList 

nRDDType 

is an integer that represents the type of the RDD you wish to 

list. 

nRDDType = 1 Full RDD implementation 

nRDDType = 2 Import/Export only driver. 

RDDLIST() returns a one-dimensional array of the RDD names registered with the application 

as nRDDType. 

368.14.169 RDDNAME() 

RDDNAME() ⇒ cRDDName 

RDDNAME() returns a character string, cRDDName, the registered name of the active RDD in 

the current or specified work area.


368.14.170 RDDSETDEFAULT() 

RDDSETDEFAULT([cNewDefaultRDD]) ⇒ cPreviousDefaultRDD 

cNewDefaultRDD 

is a character string, the name of the RDD that is to be made 

the new default RDD in the application. 

RDDSETDEFAULT() is an RDD function that sets or returns the name of the previous default 

RDD driver and, optionally, sets the current driver to the new RDD driver specified by 

cNewDefaultRDD. 

368.14.171 READINSERT() 

READINSERT([lToggle]) ⇒ lCurrentMode 

lToggle 

toggles the insert mode on or off. True (‘.T.’) turns insert on, 

while false (‘.F.’) turns insert off. The default is false (‘.F.’) 

or the last user-selected mode in READ or MEMOEDIT(). 

READINSERT() returns the current insert mode state as a logical value. 

368.14.172 READMODAL() 

READMODAL(aGetList) ⇒ NIL 

aGetList 

is an array containing a list of Get objects to edit. 

READMODAL() is like the READ command, but takes a GetList array as an argument and does 

not reinitialize the GetList array when it terminates. The GET system is implemented using a 

public array called GetList. Each time an @...GET command executes, it creates a Get object and 

adds to the currently visible GetList array. The standard READ command is preprocessed into a 

call to READMODAL() using the GetList array as its argument. 

368.14.173 READVAR() 

READVAR() ⇒ cVarName 

READVAR() returns the name of the variable associated with the current Get object or the variable 

being assigned by the current MENU TO command as an uppercase character string. 

368.14.174 RECNO() 

Record number 

RECNO() ⇒ nRecord 

RECNO() returns the current record number as an integer numeric value. If the work area contains 

a database file with zero records, RECNO() returns one, BOF() and EOF() both return 

true (‘.T.’), and LASTREC() returns zero. If the record pointer is moved past the last record,


RECNO() returns LASTREC() + 1 and EOF() returns true (‘.T.’). If an attempt is made to 

move before the first record, RECNO() returns the record number of the first logical record in the 

database file and BOF() returns true (‘.T.’). If no database file is open, RECNO() will return a 

zero. 

368.14.175 RECSIZE() 

Record size 

RECSIZE() ⇒ nBytes 

RECSIZE() returns, as a numeric value, the record length, in bytes, of the database file open in 

the current work area. RECSIZE() returns zero if no database file is open. 

368.14.176 REPLICATE() 

REPLICATE(cString, nCount) ⇒ cRepeatedString 

cString is the character string to repeat. 

nCount 

is the number of times to repeat cString. 

REPLICATE() returns a character string. Specifying a zero as the nCount argument returns a 

null string (""). 

368.14.177 RESTSCREEN() 

Restore screen 

RESTSCREEN([nTop], [nLeft], 

[nBottom], [nRight], cScreen) ⇒ NIL 


cScreen 

define the coordinates of the screen information contained in 

cScreen. If the cScreen was saved without coordinates to preserve 

the entire screen, no screen coordinates are necessary 

with RESTSCREEN(). 

is a character string containing the saved screen region. 

RESTSCREEN() is a screen function that redisplays a screen region saved with SAVE- 

SCREEN(). The target screen location may be the same as or different than the original location 

when the screen region was saved. 

368.14.178 RIGHT() 

RIGHT(cString, nCount) ⇒ cSubString 

cString is the character string from which to extract characters. 

nCount is the number of characters to extract. 

RIGHT() returns the rightmost nCount characters of cString. If nCount is zero, RIGHT() returns 

a null string (""). If nCount is negative or larger than the length of the character string,


RIGHT() returns cString. 

368.14.179 RLOCK() 

Record lock 

RLOCK() ⇒ lSuccess 

RLOCK() is a network function that locks the current record, preventing other users from updating 

the record until the lock is released. RLOCK() provides a shared lock, allowing other users 

read-only access to the locked record while allowing only the current user to modify it. A record 

lock remains until another record is locked, an UNLOCK is executed, the current database file is 

closed, or an FLOCK() is obtained on the current database file. 

368.14.180 ROUND() 

ROUND(nNumber, nDecimals) ⇒ nRounded 

nNumber is the numeric value to round. 

nDecimals 

defines the number of decimal places to retain. Specifying a 

negative nDecimals value rounds whole number digits. 

ROUND() is a numeric function that rounds nNumber to the number of places specified by 

nDecimals. Specifying a zero or negative value for nDecimals allows rounding of whole numbers. 

A negative nDecimals indicates the number of digits to the left of the decimal point to 

round. Digits between five to nine, inclusive, are rounded up. Digits below five are rounded 

down. 

368.14.181 ROW() 

ROW() ⇒ nRow 

ROW() returns the cursor row position as an integer numeric value. The range of the return value 

is zero to MAXROW(). 

368.14.182 RTRIM() 

Right trim 

[R]TRIM(cString) ⇒ cTrimString 

cString is the character string to copy without trailing spaces. 

RTRIM() returns a copy of cString with the trailing spaces removed. If cString is a null string 

("") or all spaces, RTRIM() returns a null string ("").


368.14.183 SAVESCREEN() 

SAVESCREEN([nTop], [nLeft], 

[nBottom], [nRight]) ⇒ cScreen 


define the coordinates of the screen region to save. Default is 

the entire screen. 

SAVESCREEN() returns the specified screen region as a character string. 

368.14.184 SCROLL() 

SCROLL([nTop], [nLeft], 

[nBottom], [nRight], [nVert] [nHoriz]) ⇒ NIL 

nTop, nLeft, nBottom, nRight define the scroll region coordinates. 

nVert 

nHoriz 

defines the number of rows to scroll, vertically. A positive 

value scrolls up the specified number of rows. A negative 

value scrolls down the specified number of rows. A value of 

zero disables vertical scrolling. If nVert is not specified, zero 

is assumed. 

defines the number of rows to scroll horizontally. A positive 

value scrolls left the specified number of columns. A negative 

value scrolls right the specified number of columns. A value 

of zero disables horizontal scrolling. If nHoriz is not specified, 

zero is assumed. If you supply neither nVert or nHoriz 

parameters to SCROLL(), the area specified by the first four 

parameters will be blanked. 

SCROLL() is a screen function that scrolls a screen region up or down a specified number of 

rows. When a screen scrolls up, the first line of the region is erased, all other lines are moved 

up, and a blank line is displayed in the current standard color on the bottom line of the specified 

region. If the region scrolls down, the operation is reversed. If the screen region is scrolled more 

than one line, this process is repeated. 

368.14.185 SECONDS() 

SECONDS() ⇒ nSeconds 

SECONDS() returns the system time as a numeric value in the form seconds.hundredths. The numeric 

value returned is the number of seconds elapsed since midnight, and is based on a twentyfour 

hour clock in a range from zero to 86399. 

368.14.186 SELECT() 

SELECT([cAlias]) ⇒ nWorkArea 

cAlias 

is the target work area alias name.


SELECT() returns the work area of the specified alias as a integer numeric value. 

368.14.187 SET() 

SET(nSpecifier, [expNewSetting], [lOpenMode]) 

⇒ CurrentSetting 

nSpecifier 

expNewSetting 

lOpenMode 

SET() returns the current value of the specified setting. 

is a numeric value that identifies the setting to be inspected or 

changed. 

is an optional argument that specifies a new value for 

the nSpecifier. The type of expNewSetting depends on 

nSpecifier. 

is a logical value that indicates whether or not files are opened 

for some settings. A value of false (‘.F.’) means the file 

should be truncated. A value of true (‘.T.’) means the file 

should be opened in append mode. In either case, if the file 

does not exist, it is created. If this argument is not specified, 

the default is append mode. 

Inside nB, the function SET() is not so easy to use as inside the Clipper environment. This 

because nB cannot support manifest constants and a numeric specifier nSpecifier is not easy to 

manage. Instead of SET() you can use SETVERB(). 

368.14.188 SETBLINK() 

SETBLINK([lToggle]) ⇒ lCurrentSetting 

lToggle 

SETBLINK() returns the current setting as a logical value. 

368.14.189 SETCANCEL() 

SETCANCEL([lToggle]) ⇒ lCurrentSetting 

lToggle 

SETCANCEL() returns the current setting as a logical value. 

changes the meaning of the asterisk (*) character when it 

is encountered in a SETCOLOR() string. Specifying true 

(‘.T.’) sets character blinking on and false (‘.F.’) sets background 

intensity. The default is true (‘.T.’). 

changes the availability of Alt-C and Ctrl-Break as termination 

keys. Specifying true (‘.T.’) allows either of these keys 

to terminate an application and false (‘.F.’) disables both 

keys. The default is true (‘.T.’).


368.14.190 SETCOLOR() 

SETCOLOR([cColorString]) ⇒ cColorString 

cColorString 

368.14.191 SETCURSOR() 

SETCURSOR([nCursorShape]) ⇒ nCurrentSetting 

nCursorShape 

is a character string containing a list of color attribute settings 

for subsequent screen painting. 

is a number indicating the shape of the cursor. 

nCursorShape == 0 None 

nCursorShape == 1 Underline 

nCursorShape == 2 Lower half block 

nCursorShape == 3 Full block 

nCursorShape == 4 Upper half block 

SETCURSOR() returns the current cursor shape as a numeric value. 

368.14.192 SETKEY() 

SETKEY(nInkeyCode, [bAction]) ⇒ bCurrentAction 

nInkeyCode is the INKEY() value of the key to be associated or queried. 

bAction 

specifies a code block that is automatically executed whenever 

the specified key is pressed during a wait state. 

SETKEY() returns the action block currently associated with the specified key, or NIL if the 

specified key is not currently associated with a block. 

368.14.193 SETMODE() 

SETMODE(nRows, nCols) ⇒ lSuccess 

nRows 

nCols 

is the number of rows in the desired display mode. 

is the number of columns in the desired display mode. 

SETMODE() is an environment function that attempts to change the mode of the display hardware 

to match the number of rows and columns specified. The change in screen size is reflected 

in the values returned by MAXROW() and MAXCOL().


368.14.194 SETPOS() 

Set position 

SETPOS(nRow, nCol) ⇒ NIL 

nRow, nCol 

define the new screen position of the cursor. These values may 

range from 0, 0 to MAXROW(), MAXCOL(). 

SETPOS() is an environment function that moves the cursor to a new position on the screen. 

After the cursor is positioned, ROW() and COL() are updated accordingly. 

368.14.195 SETPRC() 

Set printer row column 

SETPRC(nRow, nCol) ⇒ NIL 

nRow is the new PROW() value. 

nCol is the new PCOL() value. 

SETPRC() is a printer function that sends control codes to the printer without changing the 

tracking of the printhead position. 

368.14.196 SOUNDEX() 

SOUNDEX(cString) ⇒ cSoundexString 

cString is the character string to convert. 

SOUNDEX() returns a four-digit character string in the form A999. 

368.14.197 SPACE() 

SPACE(nCount) ⇒ cSpaces 

nCount 

is the number of spaces to return. 

SPACE() returns a character string. If nCount is zero, SPACE() returns a null string (""). 

368.14.198 SQRT() 

SQRT(nNumber) ⇒ nRoot 

nNumber 

is a positive number to take the square root of. 

SQRT() returns a numeric value calculated to double precision. The number of decimal places 

displayed is determined solely by SET DECIMALS regardless of SET FIXED. A negative


nNumber returns zero. 

368.14.199 STR() 

String 

STR(nNumber, [nLength], [nDecimals]) ⇒ cNumber 

nNumber 

nLength 

nDecimals 

STR() returns nNumber formatted as a character string. 

368.14.200 STRTRAN() 

STRTRAN(cString, cSearch, 

[cReplace], [nStart], [nCount]) ⇒ cNewString 

is the numeric expression to convert to a character string. 

is the length of the character string to return, including decimal 

digits, decimal point, and sign. 

is the number of decimal places to return. 

cString is the character string or memo field to search. 

cSearch 

is the sequence of characters to locate. 

is the sequence of characters with which to replace cSearch. 

cReplace 

If this argument is not specified, the specified instances of the 

search argument are replaced with a null string (""). 

nStart 

is the first occurrence that will be replaced. If this argument is 

omitted, the default is one. 

nCount 

is the number of occurrences to replace. If this argument is 

not specified, the default is all. 

STRTRAN() returns a new character string with the specified instances of cSearch replaced with 

cReplace. 

368.14.201 STUFF() 

STUFF(cString, nStart, 

nDelete, cInsert) ⇒ cNewString 

cString 

is the target character string into which characters are inserted 

and deleted. 

nStart 

is the starting position in the target string where the insertion/deletion 

occurs. 

nDelete is the number of characters to delete. 

cInsert 

is the string to insert. 

STUFF() returns a copy of cString with the specified characters deleted and with cInsert inserted.


368.14.202 SUBSTR() 

Sub string 

SUBSTR(cString, nStart, [nCount]) ⇒ cSubstring 

cString is the character string from which to extract a substring. 

is the starting position in cString. If nStart is positive, it is 

nStart 

relative to the leftmost character in cString. If nStart is negative, 

it is relative to the rightmost character in the cString. 

is the number of characters to extract. If omitted, the substring 

begins at nStart and continues to the end of the string. If 

nCount 

nCount is greater than the number of characters from nStart 

to the end of cString, the extra is ignored. 

SUBSTR() is a character function that extracts a substring from another character string or memo 

field. 

368.14.203 TIME() 

TIME() ⇒ cTimeString 

TIME() returns the system time as a character string in the form hh:mm:ss. hh is hours in 24-hour 

format, mm is minutes, and ss is seconds. 

TIME() is a time function that displays the system time on the screen or prints it on a report. 

368.14.204 TONE() 

TONE(nFrequency, nDuration) ⇒ NIL 

nFrequency 

nDuration 

is a positive numeric value indicating the frequency of the 

tone to sound. 

is a positive numeric value indicating the duration of the tone 

measured in increments of 1/18 of a second. For example, an 

nDuration value of 18 represents one second. 

For both arguments, noninteger values are truncated (not rounded) to their integer portion. 

368.14.205 TRANSFORM() 

TRANSFORM(exp, cSayPicture) ⇒ cFormatString 

exp 

cSayPicture 

is the value to format. This expression can be any valid data 

type except array, code block, and NIL. 

is a string of picture and template characters that describes the 

format of the returned haracter string. 

TRANSFORM() converts exp to a formatted character string as defined by cSayPicture.


368.14.206 TYPE() 

TYPE(cExp) ⇒ cType 

cExp 

TYPE() returns one of the following characters: 

A 

Array 

B Block 

C Character 

D Date 

L Logical 

M Memo 

N Numeric 

O 

Object 

U NIL, local, or static 

UE Error syntactical 

UI Error indeterminate 

is a character expression whose type is to be determined. 

cExp can be a field, with or without the alias, a private or 

public variable, or an expression of any type. 

TYPE() is a system function that returns the type of the specified expression. TYPE() is like 

VALTYPE() but uses the macro operator (&) to determine the type of the argument. VALTYPE(), 

by contrast, evaluates an expression and determines the data type of the return value. 

368.14.207 UPDATED() 

UPDATED() ⇒ lChange 

UPDATED() returns true (‘.T.’) if data in a GET is added or changed; otherwise, it returns false 

(‘.F.’). 

368.14.208 UPPER() 

UPPER(cString) ⇒ cUpperString 

cString is the character string to convert. 

UPPER() returns a copy of cString with all alphabetical characters converted to uppercase. All 

other characters remain the same as in the original string. 

368.14.209 USED() 

USED() ⇒ lDbfOpen 

USED() returns true (‘.T.’) if there is a database file in USE in the current work area; otherwise, 

it returns false (‘.F.’).


368.14.210 VAL() 

Value 

VAL(cNumber) ⇒ nNumber 

cNumber 

is the character expression to convert. 

VAL() is a character conversion function that converts a character string containing numeric 

digits to a numeric value. When VAL() is executed, it evaluates cNumber until a second decimal 

point, the first non-numeric character, or the end of the expression is encountered. 

368.14.211 VALTYPE() 

Value type 

VALTYPE(exp) ⇒ cType 

exp is an expression of any type. 

VALTYPE() returns a single character representing the data type returned by exp. VALTYPE() 

returns one of the following characters: 

A 

Array 

B Block 

C Character 

D Date 

L Logical 

M Memo 

N Numeric 

O 

Object 

U NIL 

VALTYPE() is a system function that takes a single argument, evaluates it, and returns a one 

character string describing the data type of the return value. 

368.14.212 YEAR() 

YEAR(dDate) ⇒ nYear 


YEAR() returns the year of the specified date value including the century digits as a four-digit 

numeric value. The value returned is not affected by the current DATE or CENTURY format. 

Specifying a null date (CTOD("")) returns zero.


368.15 nB functions 

Some functions made into nB are available for macro use. Not all available functions are here 

documented. 

368.15.1 ACCEPT() 

ACCEPT( Field, [cMessage], [cHeader] ) ⇒ updatedField|NIL 

It is a prompt function that shows cMessage asking to type something into Field. It returns the 

updated data or NIL if [ Esc ] was pressed. The string cHeader is showed centered at the top 

window. 

368.15.2 ACHOICE() 

ACHOICE(nTop, nLeft, nBottom, nRight, 

acMenuItems, 

[alSelectableItems], 

[nInitialItem], 

[lButtons | aButtons]) ⇒ nPosition 

nTop, nLeft, nBottom, nRight are the window coordinates. 

acMenuItems 

is an array of character strings to display as the menu items. 

is a parallel array of logical values (one element for each item 

in acMenuItems) that specify the selectable menu items. Elements 

can be logical values or character strings. If the ele- 

alSelectableItems 

ment is a character string, it is evaluated as a macro expression 

which should evaluate to a logical data type. A value of 

false (‘.F.’) means that the corresponding menu item is not 

available, and a value of true (‘.T.’) means that it is available. 

By default, all menu items are available for selection. 

nInitialItem 

is the position in the acMenuItems array of the item that will 

be highlighted when the menu is initially displayed. 

lButtons 

if True means that default buttons will appear. 

aButtons 

is an array of buttons. 

aButtons[n][1] == N the nth button row position; 

aButtons[n][2] == N the nth button column position; 

aButtons[n][3] == C the nth button text; 

aButtons[n][4] == B the nth button code block. 

ACHOICE() returns the numeric position in the acMenuItems array of the menu item selected. 

If no choice is made, ACHOICE() returns zero. 

368.15.3 ACHOICEWINDOW() 

ACHOICEWINDOW( acMenuItems, [cDescription], 

nTop, nLeft, nBottom, nRight, 

[alSelectableItems], 

[nInitialItem] ) ⇒ nPosition 

acMenuItems 

is an array of character strings to display as the menu items.


cDescription is a header to be shown at the top of window. 


is a parallel array of logical values (one element for each item 

in acMenuItems) that specify the selectable menu items. Elements 

can be logical values or character strings. If the element 

is a character string, it is evaluated as a macro expres- 

alSelectableItems 

sion which should evaluate to a logical data type. A value of 

false (‘.F.’) means that the corresponding menu item is not 

available, and a value of true (‘.T.’) means that it is available. 

By default, all menu items are available for selection. 

is the position in the acMenuItems array of the item that will 

nInitialItem 

be highlighted when the menu is initially displayed. 

ACHOICEWINDOW() calls ACHOICE() with a window border around the ACHOICE() screen 

area. 

368.15.4 ALERTBOX() 

ALERTBOX( cMessage, [aOptions] ) ⇒ nChoice 

is the message text displayed, centered, in the alert box. If the 

cMessage 

message contains one or more semicolons, the text after the 

semicolons is centered on succeeding lines in the dialog box. 

aOptions defines a list of up to 4 possible responses to the dialog box. 

ALERTBOX() returns a numeric value indicating which option was chosen. If the [ Esc ] key is 

pressed, the value returned is zero. The ALERTBOX() function creates a simple modal dialog. 

The user can respond by moving a highlight bar and pressing the Return or SpaceBar keys, or 

by pressing the key corresponding to the first letter of the option. If aOptions is not supplied, a 

single "Ok" option is presented. 

ALERTBOX() is similar to ALERT() but it accept mouse input. 

368.15.5 ATB() 

ATB( [nTop], [nLeft], [nBottom], [nRight], 

aArray, [nSubscript], 

[acColSayPic], 

[acColTopSep], [acColBodySep], [acColBotSep], 

[acColHead], [acColFoot], 

[abColValid], 

[abColMsg], 

[cColor], [abColColors], 

[lModify], 

[lButtons | aButtons] ) ⇒ NIL 

nTop, nLeft, nBottom, nRight defines the screen area where browse have to take place. 

aArray bidimensional array to be browsed. 

nSubscript starting array position. 

acColSayPic is the picture array. 

acColTopSep is the top separation array: default is chr(194)+chr(196).


acColBodySep is the body separation array: default is chr(179). 

acColBotSep is the bottom separation array: default is chr(193)+chr(196). 

acColHead 

is the header array for every column. 

acColFoot 

is the footer array for every column. 

abColValid 

is the validation array that specify when a field is properly 

filled. The condition must be specified in code block format. 

is the message array that permits to show information at the 

abColMsg 

bottom of browse area. The array must be composed with 

code blocks which result with a character string. 

cColor 

is the color string: it may be longer than the usual 5 elements. 

is the color code block array. The code block receive as pa- 

abColColors 

rameter the value contained inside the field and must return 

an array containing two numbers: they correspond to the two 

color couple from cColor. 

lModify indicates whether the browse can modify data. 

lButtons 

if True, default buttons are displayed. 

aButtons 

array of buttons. 

aButtons[n][1] N the nth button row position; 

aButtons[n][2] N the nth button column position; 

aButtons[n][3] C the nth button text; 

aButtons[n][4] B the nth button code block. 

This function starts the browse of a bidimensional array. Only arrays containing monodimensional 

array containing the same kind of editable data are allowed. The function can handle a 

maximum of 61 columns. 

368.15.6 BCOMPILE() 

BCOMPILE( cString ) ⇒ bBlock 

Compiles the string cString and returns the code block bBlock 

368.15.7 BUTTON() 

BUTTON( @aButtons, 

[nRow], [nCol], [cText], [cColor], 

[bAction] ) ⇒ NIL 

aButtons 

the array of buttons to be increased with a new button array. 

nRow and nCol 

is the row and column starting position for the button string. 

cText 

is the text that make up the button. 

cColor 

is the color string. 

bAction is the code block associated to the button. 

This function adds to aButtons a new button array. Please note that the button array added is 

compatible only with the READ() function and not the other function using array of buttons: the 

others do not have a color string.


368.15.8 COLORARRAY() 

COLORARRAY( cColor ) ⇒ aColors 

cColors 

a color string to be translated into a color array. 

This function transform a color string into a color array. The array has as many elements as the 

colors contained inside cColor string. 

368.15.9 COORDINATE() 

COORDINATE( [@nTop, @nLeft], @nBottom, @nRight, 

[cHorizontal], [cVertical] ) ⇒ NIL 

nTop, nLeft, nBottom and nRight 

cHorozontal 

cVertical 

are the starting position of a window that is to be differently 

aligned. 

determinates the horizontal alignment: 

"L" all left; 

"l" middle left; 

"C" center; 

"c" center; 

"R" all right; 

"r" middle right. 

determinate the vertical alignment: 

"T" top; 

"t" up; 

"C" center; 

"c" center; 

"B" bottom; 

"b" down. 

This function helps with the windows alignment recalculating and modifying nTop, nLeft, 

nBottom and nRight in the way to obtain the desired alignment. 

368.15.10 COPYFILE() 

COPYFILE( cSourceFile, cTargetFile|cDevice ) ⇒ NIL 

cSourceFile the source filename. 

cTargetFile the target filename. 

cDevice 

the target devicename. 

This function copies the cSourceFile to cTargetFile or to cDevice.


368.15.11 DBAPP() 

DBAPP( cFileName, [acFields], 

[bForCondition], [bWhileCondition], 


[nRecord], 

[lRest], 

[cDriver] ) ⇒ NIL 

cFileName 

acFields 

bForCondition 


nNextRecord 

nRecord 

lRest 

cDriver 

the filename containing data to append to the active alias. 

array of fieldnames indicating the fields that should be updated 

on the active alias (default is all). 

a code block containing the FOR condition to respect for the 

data append. Will be appended data that makes the evaluation 

of this code block True. 

a code block containing the WHILE condition to respect for 

the data append. Will be appended data as long as the evaluation 

of this code block is True: the first time it becomes False, 

the data appending is terminated. 

if used, means that only the first nNextRecords will be appended. 

if used, means that that only the record nRecord will be appended. 

this option is not available here also if the function saves a 

place for it. 

is the optional driver name to use to open the cFileName file. 

This function is used to append data to the active alias using data from the cFileName file, that 

in this case is a ‘.DBF’ file. 

368.15.12 DBCLOSE() 

DBCLOSE() ⇒ NIL 

It is a substitution function of DBCLOSEALL() to use inside "compiled" macros, as a true DB- 

CLOSEALL() will close the macro file too. 

368.15.13 DBCONTINUE() 

DBCONTINUE() ⇒ NIL 

This function resumes a pending DBLOCATE(). 

368.15.14 DBCOPY() 

DBCOPY( cFileName, [acFields], 



[nRecord], 

[lRest], 

[cDriver] ) ⇒ NIL


cFileName 

acFields 

bForCondition 


nNextRecord 

nRecord 

lRest 

cDriver 

the target filename for the data contained inside the active 

alias. 

array of fieldnames indicating the fields that should be used 

from the active alias (default is all). 

a code block containing the FOR condition to respect for the 

data copy. Will be copied the data that makes the evaluation 

of this code block True. 


the data copy. Will be copied data as long as the evaluation 

of this code block is True: the first time it becomes False, the 

data copying is terminated. 

if used, means that only the first nNextRecords will be 

copied. 

if used, means that that only the record nRecord will be 

copied. 

if used means that only the remaining records inside the active 

alias are copied. 

is the optional driver name to use to open the cFileName file. 

This function is used to copy data to cFileName form the active alias. 

368.15.15 DBCOPYSTRUCT() 

DBCOPYSTRUCT( cDatabase, [acFields] ) ⇒ NIL 

cDatabase 

acFields 

is a structure ‘.DBF’ file that will be filled with structure information 

about the active alias. 

is an array of fieldnames that should be taken into consideration. 

This function creates a structure ‘.DBF’ file copying the structure of the active alias. 

368.15.16 DBCOPYXSTRUCT() 

DBCOPYXSTRUCT( cExtendedDatabase ) ⇒ NIL 

cExtendedDatabase 

is a structure ‘.DBF’ file that will be filled with structure information 

about the active alias, accepting extended structure 

informations. 

This function creates a structure ‘.DBF’ file copying the structure of the active alias. This function 

accept non-standard structure, that is, the extended structure available inside Clipper. 

368.15.17 DBDELIM() 

DBDELIM( lCopyTo, cFileName, [cDelimiter], [acFields], 


[nNextRecords], [nRecord], [lRest] ) ⇒ NIL


lCopyTo 

cFileName 

cDelimiter 

acFields 

bForCondition 


nNextRecord 

nRecord 

lRest 

if True the function work copying data to cFileName from the 

active alias, if False the function work appending data from 

cFileName to the active alias. 

the filename containing data to append to the active alias or 

to use as the target of the data copy from the active alias. 

the delimiter string (or character) used to separate fields inside 

cFileName. 

array of fieldnames indicating the fields of the active alias that 

should be taken into consideration (default is all). 

a code block containing the FOR condition to respect. The operation 

will be made for all records that respect the condition. 

a code block containing the WHILE condition to respect. The 

first time it becomes False, the operation is terminated. 

if used, means that only the first nNextRecords will be appended/copied. 

if used, means that that only the record nRecord will be ap- 

pended/copied. 

if used means that only the remaining records will be taken 

into consideration. 

This function is used to append data to the active alias using data from the cFileName file or to 

copy data into cFileName using the active alias as the source. cFileName is a delimited ASCII 

file. 

368.15.18 DBISTATUS() 

DBISTATUS() ⇒ cDBInformations 

This function returns the informations on the active alias in a text form. 

368.15.19 DBISTRUCTURE() 

DBISTRUCTURE() ⇒ cTextStructure | NIL 

This function returns the structure information on the active alias in a text form. 

368.15.20 DBJOIN() 

DBJOIN( cAlias, cDatabase, 

[acFields], [bForCondition] ) ⇒ NIL 

cAlias 

cDatabase 

acFields 

the name of the alias to use to merge with records from the 

active alias. 

the target ‘.DBF’ filename. 

the array of fieldnames which represent the projection of 

fields form both Aliases into the new ‘.DBF’ file. If not specified, 

all fields from the primary work area are included in the 

target ‘.DBF’ file. 

This function creates a new database file by merging selected records and fields form two work 

areas (Aliases) based on a general condition. It works by making a complete pass through the 

secondary work area cAlias for each record in the primary work area (the active alias), evaluating


the condition for each record in the secondary work area. When bForCondition is evaluated True, 

a new record is created in the target database file cDatabase using the fields specified from both 

work areas inside acFields. 

368.15.21 DBLABELFORM() 

DBLABELFORM( cLabel, [lToPrinter], [cFile], 

[lNoConsole], [bForCondition], [bWhileCondition], 

[nNextRecords], [nRecord], [lRest], [lSample] ) 

⇒ NIL 

cLabel 

is the name of the label file (.LBL) that contains the label 

format definition. 

lToPrinter 

if True, the output is copied to printer (‘LPT1:’). 

cFile 

if present, it is the name of a ASCII file where the output is 

copied. 

lNoConsole 

if True, the output is not sent to the console. 

a code block containing the FOR condition to respect for label 

bForCondition 

print. Only the records contained inside the active alias that 

respect the condition will be used for labels. 



the label print. The first time that the condition is False, the 

label print terminates. 

nNextRecord 

if used, means that only the first nNextRecords will be used. 

nRecord 

if used, means that that only the record nRecord will be used. 

lRest 


alias will be used. 

lSample if True displays test labels as rows of asterisks. 

This function prints labels to the console. 

368.15.22 DBLIST() 

DBLIST( [lToDisplay], abListColumns, 

[lAll], 


[nNextRecords], [nRecord], [lRest], 

[lToPrinter], [cFileName] ) 

lToDisplay if True the printout is sent to the console screen. 

abListColumns 

is an array of columns expressions to list. 

lAll 

if True prints all the records contained inside the active alias. 

a code block containing the FOR condition to respect. Only 

bForCondition 

the records contained inside the active alias that respect the 

condition will be used for list. 



first time that the condition is False, the list terminates. 

nNextRecord 


nRecord 


lRest 



lToPrinter 

if True, the output is copied to printer (‘LPT1:’). 

cFileName 

if present, it is the name of a ASCII file where the output is 

copied.


This function prints a list of records to the console. 

368.15.23 DBLOCATE() 

DBLOCATE( [bForCondition], [bWhileCondition], 

[nNextRecords], [nRecord], [lRest] ) ⇒ NIL 

bForCondition 


nNextRecord 

nRecord 

lRest 



condition will be taken into consideration. 


first time that the condition is False, the locate terminates. 





This function searches sequentially for the first record matching the FOR and WHILE conditions. 

Once a DBLOCATE() has been issued you can resume the search from the current record pointer 

position with DBCONTINUE(). 

The WHILE condition and the scope (nNextRecord, nRecord and lRest) apply only to the initial 

DBLOCATE() and are not operational for any subsequent DBCONTINUE() call. 

368.15.24 DBOLDCREATE() 

DBOLDCREATE( cDatabase, cExtendedDatabase, 

[cDriver], [lNew], [cAlias] ) ⇒ NIL 

cDatabase 

cExtendedDatabase 

cDriver 

lNew 

cAlias 

is the name of the new database file, with an optional drive and 

directory, specified as a character string. If specified without 

an extension (.dbf) is assumed. 

is a ‘.DBF’ file containing the structure information of the file 

to create. 

specifies the replaceable database driver (RDD) to use to process 

the current work area. cDriver is the name of the RDD 

specified as a character expression. 

if True the newly created ‘.DBF’ file is opened using the next 

available work area making it the current work area (the active 

alias). 

if lNew is set to True, this is the alias name to use to open the 

file. 

This function is a old database function (superseded form DBCREATE() ) that creates a database 

file from the structure information contained inside a structure file.


368.15.25 DBPACK() 

DBPACK() ⇒ NIL 

This function eliminates definitively the active alias records previously signed for deletion. It 

works only if the active alias is opened in exclusive mode. 

368.15.26 DBSDF() 

DBSDF( lCopyTo, cFileName, [acFields], 



lCopyTo 

cFileName 

acFields 

bForCondition 


nNextRecord 

nRercord 

lReset 

if True the function works copying data to cFileName from 

the active alias, if False the function work appending data 

from cFileName to the active alias. 

the filename containing data to append to the active alias or to 

use as the target of the data copy from the active alias. 

array of fieldnames indicating the fields of the active alias that 

should be taken into consideration (default is all). 

a code block containing the FOR condition to respect. The operation 

will be made for all records that respect the condition. 


first time it becomes False, the operation is terminated. 

if used, means that only the first nNextRecords will be appended/copied. 

if used, means that that only the record nRecord will be ap- 

pended/copied. 

if used means that only the remaining records will be taken 

into consideration. 

This function is used to append data to the active alias using data from the cFileName file or to 

copy data into cFileName using the active alias as the source. cFileName is a SDF ASCII file. 

368.15.27 DBSORT() 

DBSORT( cDatabase, [acFields], 



cDatabase the ‘.DBF’ file to create. 

acFields 

the array of fields to be used to create the new sorted 

cDatabase file. 


bForCondition 





first time that the condition is False, the sort terminates. 

nNextRecord 

if used, means that only the first nNextRecords inside the active 


nRecord 


lRest 


alias will be used.


Copy the active alias to a ‘.DBF’ file in sorted order. 

368.15.28 DBTOTAL() 

DBTOTAL( cDatabase, bKey, [acFields], 



cDatabase 

bKey 

acFields 

bForCondition 


nNextRecords 

nRecord 

lRest 

the ‘.DBF’ file to create that will contain the copy of summarised 

records. 

the code block key expression that should correspond to the 

key expression of the active index of the active alias. 

the array of fields to be used to create the new cDatabase file. 





first time that the condition is False, the sort terminates. 

if used, means that only the first nNextRecords inside the active 





This function summarises records by key value to a ‘.DBF’ file. It sequentially process the active 

alias scanning the specified scope of records. Records with the same key will be summarised 

inside the destination ‘.DBF’ file. The value of numeric fields of records with the same key are 

added. 

368.15.29 DBUPDATE() 

DBUPDATE( cAlias, bKey, [lRandom], [bReplacement] ) 

cAlias 

bKey 

lRandom 

bReplacement 

is the alias containing data to be used to update the active 

alias. 

is a code block expression using information form the cAlias 

to obtain a key to refer to the active alias. 

if True, allows record in the cAlias to be in any order. In this 

case, the active alias must be indexed with the same key as 

bKey. 

is the code block that will be executed when records matches: 

it should contains the criteria for data update. 

This function updates the active alias with data from another .DBF file. 

Example: 

dbUpdate( "INVOICE", {|| LAST}, .T.,; 

{|| FIELD->TOTAL1 := INVOICE->SUM1,; 

FIELD->TOTAL2 := INVOICE->SUM2 } )


368.15.30 DBZAP() 

DBZAP() ⇒ NIL 

This function erases immediately all the records contained inside the active alias. 

368.15.31 DISPBOXCOLOR() 

DISPBOXCOLOR( [nColorNumber], [cBaseColor] ) ⇒ cColor 

nColorNumber 

cBaseColor 

may be 1 or 2 and are the two color used to create shadowed 

borders. 1 is usually used for the left and top line; 2 is used 

for the right and bottom line. 

is the starting color string. The default is the actual color. 

This function return a color string used for DISPBOXSHADOW() the function that create a 

shadowed border around a screen window. 

368.15.32 DISPBOXSHADOW() 

DISPBOXSHADOW( nTop, nLeft, nBottom, nRight, 

[cBoxString], [cColor1], [cColor2] ) ⇒ NIL 

nTop, nLeft, nBottom and nRight are the screen coordinate where the box is to be displayed. 

cBoxString 

is the box string containing the character to use to build the 

box. Default is a single line box. 

cColor1 

is the color string to use for the left and top side of the box. 

cColor2 

is the color string to use for the right and bottom side of the 

box. 

This function draws a screen box like DISPBOX() but allowing the variation of colors around the 

border to simulate a sort of shadow. 

368.15.33 DIR() 

DIR( [cFileSpec], [lDrives], [lDirs], [lFiles], 

[lNoDirReturn], [nSortColumn] ) ⇒ cPathname 

cFileSpec the filename or Pathname, also with wildcards, to be searched. 

lDrives true (‘.T.’) means: include drives letters. 

lDirs 

true (‘.T.’) means: include directory names. 

lFiles true (‘.T.’) means: include file names. 

true (‘.T.’) means: do not return the shown directory if [ Esc ] 

lNoRirReturn 

is used to exit. 

the column number to use to sort the list. The columns are: 

Name = 1, 

Size = 2, 

nSortColumn 

Date = 3, 

Time = 4, 

Attribute = 5. 

It is not possible to sort for extention.


It is a window function useful to search a file or a directory. The complete pathname of the 

selected file is returned. 

368.15.34 DOC() 

DOC( [cTextFileName] ) ⇒ NIL 

cTextFileName 

can contain the text file to open and edit; if empty, the editing 

of ‘UNTITLED.TXT’ will start. 

It is the nB Text editor useful for small text files (less then 64K) and contains a complete menu 

that can be started with[F10]. 

Attention: doc() should not be used inside macros. 

368.15.35 DOTLINE() 

DOTLINE() ⇒ NIL 

This function is a "dot" command line useful for calculations resolution. The dot-line content 

may be passed to the keyboard buffer. 

368.15.36 DTEMONTH() 

Date of month 

DTEMONTH( nMonth, cLanguage ) ⇒ cMonth 

nMonth the month number. 

cLanguage the language name. 

This function translates the nMonth number into the month name translated using the 

cLanguage language. 

368.15.37 DTEWEEK() 

Date of week 

DTEWEEK( nWeek, cLanguage ) ⇒ cWeek 

nWeek 

cLanguage 

is the week number (1 is Sunday, 7 is Saturday) to be translated 

into text. 

is the language name into which the week must be expressed. 

At the moment it works only for Italian, so cLanguage can 

only contain "ITALIANO". 

This function translates the week number into the week name translated using the cLanguage 

language.


368.15.38 EX() 

Execute 

EX( cFileMacro ) ⇒ nExitCode 

Executes the macro file cFileName. The extention must be specified. 

cFileMacro may be the name of a "compiled" macro or a text macro file. 

368.15.39 GET() 

GET( @aGetList, 


{ |x| iif( pcount() > 0, Var := x, Var ) } 

[cGetPicture], [cColorString], 

[bPreExpression], [bValid] ) 

aGetList 

is the get list array that will be increased with this get(). 

nTop and nLeft define the starting position of this get object on the screen. 

Var 

is the variable that is to be edited with this get. Var is in fact 

sent to the GET() function using a code block. 

cGetPicture 

is the get picture to use for Var. 

cColorString is the color string to use for the get. 

is a code block that will be evaluated before the get object 

bPreExpression 

will became active. It must result True to obtain that the get 

object became active. 

is a code block that will be evaluated after the get object is 

bValid 

edited. It must result True to obtain that the get object may 

become inactive. 

Create screen editing masks. 

368.15.40 GVADD() 

Get validation add 

GVADD( @cField, cAdd ) ⇒ .T. 

cField the field to fill with more data. 

cAdd 

is the string to be added to the content of cField. 

This function is to be used inside GETs for pre/post validation, when a the content of a field 

should be added with more data. 

cField is returned with the same length as before to avoid troubles with current and future GETs.


368.15.41 GVDEFAULT() 

Get validation default 

GVDEFAULT( @cField, cDefault ) ⇒ .T. 

@cField 

the field to check and if empty correct with cDefault. 

cDefault is the default value to be used to replace cField. 

This function is to be used inside GETs for pre/post validation, when a field should have a default 

value. 

cField is returned with the same length as before to avoid troubles with current and future GETs. 

368.15.42 GVFILEDIR() 

Get validation file directory 

GVFILEDIR( @cWildName ) ⇒ .T. 

cWildName 

is the file name taken from the current get to be used for search 

with DIR(). 

This function is to be used inside GETs for pre validation: the cWildName is a file name with 

wild cards that can be searched with the DIR() function after that a specific key is pressed. 

cWildName is returned with the same length as before to avoid troubles with current and future 

GETs. 

368.15.43 GVFILEEXIST() 

GVFILEEXIST( @cNameToTest, [cExtention] ) ⇒ lSuccess 

@cNameToTest 

is the file name taken from the current get to test for existence. 

cExtention is the normal extention of the file. 

This function is to be used inside GETs for post validation: the file name have to exist. 

cNameToTest is returned with the same length as before to avoid troubles with current and future 

GETs. 

368.15.44 GVFILEEXTENTION() 

GVFILEEXTENTION( @cName, cExt ) ⇒ .T. 

@cName 

the file name to be eventually corrected with file extention. 

cExt the file extention to use as default. 

This function is to use inside GETs for pre/post validation, when the content of a field should 

contain a file name that should be corrected adding a default extention if not given from the user.


368.15.45 GVSUBST() 

GVSUBST( @cField, cSubst ) ⇒ .T. 

@cField 

cSubst 

the field to be replaced with cSubst. 

is the string to be used to replace the content of cField. 

This function is to use inside GETs for pre/post validation, when the content of a field should be 

replaced with other data. 

cField is returned with the same length as before to avoid troubles with current and future GETs. 

368.15.46 HTF() 

HTF( [nInitialRecord] ) ⇒ NIL 

nInitialRecord 

is the record number where to start the Help Text File browse. 

Default is the actual record pointer. 

This function browse a Help Text File that must be already opened and be the active alias. 

368.15.47 ISFILE() 

ISFILE( cName ) ⇒ lFileExists 

cName 

is the file name (with or without path) to be checked for existence. 

This function returns true (‘.T.’) if the file cName exists. The difference between this function 

and the standard FILE() function is that ISFILE() checks for wildcards before. If cName contains 

wildcards, the result is false (‘.F.’). 

368.15.48 ISWILD() 

ISWILD( cName ) ⇒ lIsWild 

cName 

This function returns true (‘.T.’) if cName contains wildcards. 

368.15.49 ISMEMVAR() 

ISMEMVAR( cName ) ⇒ lIsMemvar 

cName 

is the file name (with or without path) to be checked for wildcards 

presence. 

is the name of a possible memvar. 

This function returns true (‘.T.’) if the cName is a declared Memvar.


368.15.50 ISCONSOLEON() 

ISCONSOLEON() ⇒ lConsoleIsOn 

This function returns true (‘.T.’) if the console will show the result of QOUT() and QQOUT(). 

368.15.51 ISPRINTERON() 

ISPRINTERON() ⇒ lPrinterIsOn 

This function returns true (‘.T.’) if the default printer will report the the result of QOUT() and 

QQOUT(). 

The default printer is ‘PRN:’ or ‘LPT1:’. If SET ALTERNATE TO is configured to send outputs 

to ‘LPT2:’ or another printer, the function will report false (‘.F.’). 

368.15.52 KEYBOARD() 

KEYBOARD( [cString] ) ⇒ NIL 

This function stuff a string into the keyboard buffer. 

368.15.53 LISTWINDOW() 

LISTWINDOW( acMenuItem, [cDescription], 

[nTop], [nLeft], [nBottom], [nRight], 

[cColorTop], [cColorBody] ) ⇒ nPosition 

acMenuItem 

is the character array containing the list of choices. 

cDescription is the header to be shown at the top window. 


cColorTop is the color to use for window header and footer. 

cColorBody 

is the color to use for the window body that is the space where 

the text appears. 

This function is an similar to achoice(), but it shows a header and footer, and it saves the screen, 

acting like a window. 

368.15.54 MEMOWINDOW() 

MEMOWINDOW( cVar, [cDescription], [nTop], [nLeft], 

[nBottom], [nRight], [cColorTop], [cColorBody], 

[lEditMode], [nLineLength], [nTabSize] ) ⇒ cVar 

cVar is the character field (variable) to be edited. 

cDescription is the header to be shown at the top window. 


cColorTop is the color to use for window header and footer. 

cColorBody 

is the color to use for the window body that is the space where 

the text appears. 

lEditMode 

is equivalent to memoedit().


nLineLength is equivalent to memoedit(). 

nTabSize is equivalent to memoedit(). 

This function lets you easily edit a long character field (memo) defining automatically a simple 

window and providing a simple help. 

368.15.55 MEMPUBLIC() 

MEMPUBLIC( cMemvarName|acMemvarNames ) ⇒ NIL 

cMemvarName 

acMemvarNames 

Creates a PUBLIC variables or a group of variables. 

368.15.56 MEMRELEASE() 

MEMRELEASE( cMemvarName|acMemvarNames ) ⇒ NIL 

is the name of the PUBLIC variable to create (max 10 characters). 

is an array of PUBLIC variable names to create (max 10 characters). 

cMemvarName is the name of the PUBLIC variable to be released. 

acMemvarNames 

is an array of PUBLIC variable names to be released. 

This function releases a previously created PUBLIC variables or a group of variables. 

368.15.57 MEMRESTORE() 

MEMRESTORE( cMemFileName, [lAdditive] ) ⇒ NIL 

cMemFileName 

lAdditive 

Retrieve memory variables form a memory file (.MEM). 

368.15.58 MEMSAVE() 

MEMSAVE( cMemFileName, [cSkeleton], [lLike] ) ⇒ NIL 

cMemFileName 

cSkeleton 

lLike 

the memory file (.MEM) to load from disk. 

if True causes memory variables loaded from the memory file 

to be added to the existing pool of memory variables. If False, 

the existing memory variables are automatically released. 

the memory file (.MEM) where public variables should be 

saved. 

the skeleton mask for defining a group of variables. Wildcard 

characters may be used: _*_ and _?_. 

if True, the variables grouped with cSkeleton are saved, else 

only the other variables are saved.


Saves memory variables to a memory file (.MEM). 

368.15.59 MENUPROMPT() 

MENUPROMPT( @aoGet, 

[nRow], [nCol], 

[cPrompt], [bBlock] ) ⇒ NIL 

aoGet 

is an array of get objects where a new get is added by 

MENUPROMPT(). These gets are read only. 

nRow and nCol 

are the screen coordinates where the menu prompt will appear. 

cPrompt is the menu prompt string. 

is the code block to execute when the cursor is on the current 

bBlock 

menu prompt. It is usually a code block that shows a message 

somewhere on the screen. 

This function should substitute the @...PROMPT command and handle the mouse. 

368.15.60 MENUTO() 

MENUTO( aoGet, nPos ) ⇒ nChoice 

aoGet 

nPos 

array of get objects. 

starting position to be edited. 

Like MENU TO. It returns the selected menu item created with MENUPROMPT(). It supports 

the mouse. 

368.15.61 MESSAGELINE() 

MESSAGELINE( [cMessage], [cColor], [nPosTop], [nPosLeft] ) 

⇒ NIL 

aMessage the message to be displayed. 

cColor 

the color string. 

the starting position where the string message would appear 

nPosTop and nPosLeft 

on the screen. Default values are respectively ROW() and 

COL(). 

MESSAGELINE() is a function that display a message on the screen on the selected position. If 

cMessage is NIL, the message is eliminated from screen restoring the previous screen content.


368.15.62 MOUSESCRSAVE() 

MOUSESCRSAVE( [nTop], [nLeft], [nBottom], [nRight] ) 

⇒ cSavedScreen 

nTop, nLeft, nBottom and nRight are the screen coordinates that will be to save the screen. 

This function works line SAVESCREEN() but it hide the mouse cursor before a screen save is 

made. 

368.15.63 MOUSESCRRESTORE() 

MOUSESCRRESTORE( [nTop], [nLeft], [nBottom], [nRight], 

[cScreen] ) ⇒ cSavedScreen 

nTop, nLeft, nBottom and nRight 

cScreen 

are the screen coordinates where the saved screen will be restored. 

is the previously saved screen to restore. 

This function works line RESTSCREEN() but it hide the mouse cursor before a screen restore is 

made. 

368.15.64 PICCHRMAX() 

PICCHRMAX( [nCol], [nMaxCol] ) ⇒ cPictureString 

nCol 

nMaxCol 

is the starting position on the screen for the get field. 

is the end position on the screen of the get field. 

This function is useful when a character field is to be used on a get object. The generated picture 

will be the of the maximum possible extention, eventually with scroll. 

368.15.65 QUIT() 

QUIT() ⇒ NIL 

Terminates program execution. 

368.15.66 READ() 

READ( aoGet, [nPos], [aButtons], [lReadOnly] ) 

⇒ lUpdated 

aoGet 

nPos 

aButtons 

lReadOnly 

is the array of get objects. 

is the starting position. 

is the array of buttons. 

if True, get fields cannot be modified; the default value is 

False.


This function is made to substitute the READMODAL() allowing the use of the mouse. The array 

aButtons is made with the help of the function BUTTON(). 

368.15.67 RF() 

RF( cFRMName, 


[nNext], [nRecord], [lRest], [lPlain], 

[cbHeading], [lBeforeEject], [lSummary], 

[lDate], [acExtra] ) ⇒ NIL 

cFRMName 

the form (.FRM) file to use to print the active alias. 

bForCondition code block for the FOR condition. 

bWhileCondition code block for the WHILE condition. 

nNext see REPORT FORM. 

nRecord see REPORT FORM 

lRest see REPORT FORM 

lPlain 

if true (‘.T.’), force the print in a simple way. 

additional header in character or code block form. If a code 

cbHeading 

block is sent, the final result must be a character string. 

lBeforeEject if true (‘.T.’), force a form feed before the print. 

lSummary if true (‘.T.’), force a summary print only. 

lDate 

if false (‘.F.’), force the print without date at the top of page. 

a character array that may be used for translating standard 

printed report form words and to add vertical and horizontal 

separations. The default value of acExtra is: 

acExtra[1] "Page No." 

acExtra 

acExtra[2] "** Subtotal **" 

acExtra[3] "* Subsubtotal *" 

acExtra[4] "*** Total ***" 

acExtra[5] " " vertical column separation 

axExtra[6] "" horizontal separation: no separation. 

This function does the same work of REPORT FORM or __ReportForm or dbReportForm, but it 

prints where qout() and qqout() print. 

368.15.68 RPT() 

RPT( cText ) ⇒ NIL 

This function prints the text contained into cText using print commands. This function accepts 

other parameters here not described, as they are not to be used for macro purpose. The printing 

is made using QOUT() and QQOUT(), this way it is sensible to the "alternate" file definition. 

368.15.69 RPTMANY() 

RPTMANY( cText, [bWhileCondition], [bForCondition] ) 

⇒ NIL 

cText 


bForCondition 

is the text to be printed. 

is a code block for a WHILE condition to respect for the 

records to print. 

is a code block for a FOR condition to respect for the records 

to print.


This function prints the text contained into cText many times: one for every record contained 

into the active alias. 

368.15.70 RPTTRANSLATE() 

RPTTRANSLATE( cText ) ⇒ cTranslatedText 

This function translates once cText replacing variables with memvars or Fields. 

368.15.71 RUN() 

RUN( cCommand ) ⇒ NIL 

This function start execution of cCommand in a DOS session. It works only if there is enough 

available memory. 

368.15.72 SAY() 

SAY( nTop, nLeft, Expr, 

[cSayPicture], [cColorString] ) ⇒ NIL 

nTop and nLeft 

define the starting position on the screen where the Expr 

should be displayed. 

nLeft is an expression that will be solved and displayed. 

cSayPicture is the picture to use to display Expr. 

cColorString is the color string to use. 

This function displays the result of Expr on the screen on the desired position. 

368.15.73 SETCOLORSTANDARD() 

SETCOLORSTANDARD( [nColor], [cColor|acColor] ) 

nColor 

cColor 

acColor 

⇒ cPreviousColor|acPreviousColor 

is the color number to take into consideration: 

0 All colors 

1 Base 

2 Menu 

3 Head 

4 Body (Say - Get) 

5 Button (Mouse buttons) 

6 Message 

7 Alert 

the color string to be associated with nColor. 

it the color array 

This function is a way to handle colors inside the application. The functions that display something 

use a default color depending on what they does. These colors may be changed with SET- 

COLORSTANDARD(), all together or only one.


368.15.74 SETFUNCTION() 

SETFUNCTION( nFunctionKey, cString ) ⇒ NIL 

nFunctionKey 

the number of the function key ( 1=F1, 12=F12) to be assigned. 

cString the character string. 

This function assigns a character string to a function key (obsolete). 

368.15.75 SETMOUSE() 

SETMOUSE( [lShow] )⇒ lPrevious 

lShow 

True shows the mouse cursor, False hide the mouse cursor, 

NIL reports only the status. 

This function is made to show, hide or report only the mouse cursor status. 

368.15.76 SETOUTPUT() 

SETOUTPUT( [cPeriperal|aPeripheral] ) 

⇒ aPrevious_Output_Peripherals 

cPeripheral is the new output peripheral for qout() and qqout() functions. 

aPeripheral 

are the new output peripherals configurations for qout() and 

qqout() functions. 

nB is organised in the way to have only one output peripheral at the time. This function help to 

make order inside SET CONSOLE, SET PRINTER and SET ALTERNATE. 

If cPeripheral contains: 

"CON" 

"PRN" 

SET CONSOLE is set to ON, 

SET PRINTER is set to OFF, 

SET ALTERNATE is set to OFF; 

SET CONSOLE is set to OFF, 

SET PRINTER is set to ON, 

SET ALTERNATE is set to OFF; 

"LPT1" 

same as "PRN"; 

otherwise 

SET CONSOLE is set to OFF, 

SET PRINTER is set to OFF,


SET ALTERNATE is set to ON, 

SET ALTERNATE TO is set to cPeripheral. 

aPeripheral is organised this way: 

aPeripheral[1] = _SET_CONSOLE 

aPeripheral[2] = _SET_PRINTER 

aPeripheral[3] = _SET_ALTERNATE 

aPeripheral[4] = _SET_ALTFILE 

aPeripheral[5] = _SET_EXTRA 

aPeripheral[6] = _SET_EXTRAFILE 

This function is necessary because SET ALTERNATE alone is not enough to print on the screen 

when the peripheral name is "CON" or to print on the printer when the peripheral name is "PRN" 

or "LPT1". In fact, in the first case, ROW() and COL() will not be updated, in the second case, 

PROW() and PCOL() will not be updated. 

This function returns an array organised in the same way as aPeripheral is, that shows the active 

output configuration. 

368.15.77 SETRPTEJECT() 

SETRPTEJECT( [lbEject] ) ⇒ lPreviousEjectMode 

This function is used to set the eject mode after every page print for RPT(). If single sheet paper is 

used, then SETRPTEJECT(.T.) must be set; for continuous paper, SETRPTEJECT(.F.) is correct. 

The default value is .F.. 

lbEject 

368.15.78 SETRPTLINES() 

SETRPTLINES() ⇒ nRemainingLines 

logical or code block, is the eject mode to set. Default is no 

change, the starting value is ‘.F.’ 

This function is used to report the number of lines available before the completion of the page 

print for RPT(). 

368.15.79 SETVERB() 

Set verbose 

SETVERB( cSpecifier, [xNewSetting], [lOpenMode] ) 

⇒ xPreviousValueSet 

cSpecifier a word that defines the kind of set is going to be considered. 

xNewSetting is the new value to set up. 

lOpenMode used only for some kind of set. 

This function is analogue to SET() but it uses a character string (with cSpecifier) and not a


number to select the set. This is made to make easier the work with macros. 

cSpecifier may contain: 

"EXACT" 

"FIXED" 

"DECIMALS" 

"DATEFORMAT" 

"EPOCH" 

"PATH" 

"DEFAULT" 

"EXCLUSIVE" 

"SOFTSEEK" 

"UNIQUE" 

"DELETED" 

"CANCEL" 

"TYPEAHEAD" 

"COLOR" 

"CURSOR" 

"CONSOLE" 

"ALTERNATE" 

"ALTFILE" 

"DEVICE" 

"EXTRA" 

"EXTRAFILE" 

"PRINTER" 

"PRINTFILE" 

"MARGIN" 

"BELL" 

"CONFIRM" 

"ESCAPE" 

"INSERT" 

"EXIT" 

"INTENSITY" 

"SCOREBOARD" 

"DELIMITERS" 

"DELIMCHARS" 

"WRAP" 

"MESSAGE" 

"MCENTER" 

368.15.80 SETVERB("EXACT") (obsolete) 

SETVERB( "EXACT", [lExact] ) ⇒ lPrevious 

If lExact is True, it forces exact comparison of character strings, including length. If it is False, 

character strings are compared until the left string length is exhausted; that is that "" (the null 

string) is equal to any other string. 

Please note that the == operator is a comparison operator for exact match and using it, 

SETVERB("EXACT", ‘.F.’) will not work.


The starting value is True; the recommended value is True. 

368.15.81 SETVERB("FIXED") 

SETVERB( "FIXED", [lFixed] ) ⇒ lPrevious 

If lFixed contains True, numeric values are displayed ever with a fixed number of decimal digits, 

depending on the value set by SETVERB("DECIMALS"). 

The starting value is False. 

The recommended value is False: if you have to display a fixed number of decimal digits it is 

better to define a good display picture. 

368.15.82 SETVERB("DECIMALS") 

SETVERB( "DECIMALS", [nDecimals] ) ⇒ nPrevious 

nDecimals is the number of digits to display after the decimal position. This set is enabled of 

disabled with SETVERB("FIXED"). 

The starting value is 8. 

368.15.83 SETVERB("DATEFORMAT") 

SETVERB( "DATEFORMAT", [cDateFormat] ) ⇒ cPrevious 

cDateFormat is a character expression that specifies the date format. 

The starting value is "dd/mm/yyyy". 

Some date format examples: 

AMERICAN 

ANSI 

BRITISH 

FRENCH 

GERMAN 

ITALIAN 

JAPAN 

USA 

368.15.84 SETVERB("EPOCH") 

SETVERB( "EPOCH", [nYear] ) ⇒ nPrevious 

"mm/dd/yyyy" 

"yyyy.mm.dd" 

"dd/mm/yyyy" 

"dd/mm/yyyy" 

"dd.mm.yyyy" 

"dd-mm-yyyy" 

"yyyy/mm/dd" 

"mm-dd-yyyy" 

nYear specifies the base year of 100-year period in which all dates containing only two year 

digits are assumed to fall. 

The starting value is 1900.


368.15.85 SETVERB("PATH") 

SETVERB( "PATH", [cPath] ) ⇒ cPrevious 

cPath identifies the paths that nB uses when searching for a file not found in the current directory. 

The list of paths can be separated by commas or semicolons. 

The starting value is "". 

368.15.86 SETVERB("DEFAULT") 

SETVERB( "DEFAULT", [cPath] ) ⇒ cPrevious 

cPath identifies the default disk drive and directory. 

The starting value is "". 

368.15.87 SETVERB("EXCLUSIVE") 

SETVERB( "EXCLUSIVE", [lExclusive] ) ⇒ lPrevious 

If lPath is True, the default database (.DBF) file open is made in exclusive mode; in the other 

case, in shared mode. 

The starting value is True. 

368.15.88 SETVERB("SOFTSEEK") 

SETVERB( "SOFTSEEK", [lSoftSeek] ) ⇒ lPrevious 

If lSoftSeek is True, if a DBSEEK() index search fails, the record pointer is moved to the next 

record with a higher key. If it is False, in case of a DBSEEK() index search failure, the record 

pointer is moved at EOF(). 


368.15.89 SETVERB("UNIQUE") (obsolete) 

SETVERB( "UNIQUE", [lUnique] ) ⇒ lPrevious 

If lUnique is True, during creation or update of ‘.DBF’ indexes, if two or more records are found 

with the same key, only the first record will be included inside the index. 

If lUnique is False, duplicated record keys are allowed. 

The starting value is False.


368.15.90 SETVERB("DELETED") 

SETVERB( "DELETED", [lDeleted] ) ⇒ lPrevious 

If lDeleted is True, record signed for deletion are not filtered, that is, these are still normally 

visible as they were not deleted. In the other case, they hare (in most cases) hidden to the user. 


368.15.91 SETVERB("CANCEL") 

SETVERB( "CANCEL", [lCancel] ) ⇒ lPrevious 

If lCancel is True, enables [ Alt+c ] and [ Ctrl+Break ] as termination keys. In the other case, not. 


368.15.92 SETVERB("TYPEAHEAD") 

SETVERB( "TYPEAHEAD", [nTypeAhead] ) ⇒ nPrevious 

nTypeAhead is the number of keystrokes the keyboard buffer can hold from a minimum of zero 

to a maximum of 4096. 


368.15.93 SETVERB("COLOR") 

SETVERB( "COLOR", [cColorString] ) ⇒ cPrevious 

nColorString defines the normal screen colors. There are five couple of colors, but only three are 

really operative: 

standard 

This is the standard color used for screen output. 

enhanced 

This is the color used for highlighted screen output. 

border 

Normally unused. 

background Normally unused. 

unselected This is the color used for GET fields without focus. 

The default color string is "BG+/B,N/W,N/N,N/N,W/N" that is: 

standard 

bright Cyan on Blue 

enhanced Black on White 

border Black on Black 

background Black on Black 

unselected White on Black 

The following table explains the use of letters inside the color string. Note that the plus sign (+) 

means high intensity, the star (*) means blink and that + and * can be allowed only to the first 

letter inside a couple. 

Color Letter Monochrome 

Black N, Space Black


Color Letter Monochrome 

Blue B Underline 

Green G White 

Cyan BG White 

Red R White 

Magenta RB White 

Brown GR White 

White W White 

Gray N+ Black 

Bright Blue B+ Bright Underline 

Bright Green G+ Bright White 

Bright Cyan BG+ Bright White 

Bright Red R+ Bright White 

Bright Magenta RB+ Bright White 

Bright Brown GR+ Bright White 

Bright White W+ Bright White 

Black U Underline 

Inverse Video I Inverse Video 

Blank X Blank 

368.15.94 SETVERB("CURSOR") 

SETVERB( "CURSOR", [lCursor] ) ⇒ lPrevious 

If lCursor is True, the cursor is showed, else it is hidden. 


368.15.95 SETVERB("CONSOLE") 

SETVERB( "CONSOLE", [lConsole] ) ⇒ lPrevious 

If lConsole is True, the output of console commands is displayed on the screen, else it is not. 


368.15.96 SETVERB("ALTERNATE") 

SETVERB( "ALTERNATE", [lAlternate] ) ⇒ lPrevious 

If lAlternate is True, the output of console commands is send also to a standard ASCII text file. 


368.15.97 SETVERB("ALTFILE") 

SETVERB( "ALTFILE", [cAlternateFilename], [lAdditive] ) 

⇒ cPrevious 

If SETVERB("ALTERNATE") is True, the output of the console is send also to 

cAlternateFilename, a standard ASCII file.


If lAdditive is True, the output is appended to the ASCII file if it already exists, else it is erased 

first. 

368.15.98 SETVERB("DEVICE") 

SETVERB( "DEVICE", [cDevice] ) ⇒ cPrevious 

cDevice is the name of the device where SAY() will display its output. 

The starting value is "SCREEN", the alternative is "PRINTER". 

The recommended value is "SCREEN". 

368.15.99 SETVERB("EXTRA") 

SETVERB( "EXTRA", [lExtra] ) ⇒ lPrevious 

If lExtra is True, the output of console commands is send also to a standard ASCII text file. 


368.15.100 SETVERB("EXTRAFILE") 

SETVERB( "EXTRAFILE", [cExtraFilename], [lAdditive] ) 

⇒ cPrevious 

If SETVERB("EXTRA") is True, the output of the console is send also to cExtraFilename, a 

standard ASCII file. 

If lAdditive is True, the output is appended to the ASCII file if it already exists, else it is erased 

first. 

368.15.101 SETVERB("PRINTER") 

SETVERB( "PRINTER", [lPrinter] ) ⇒ lPrevious 

If lPrinter is True, the output of console commands is also printed, else it is not. 


368.15.102 SETVERB("PRINTFILE") 

SETVERB( "PRINTFILE", [cPrintFileName] ) ⇒ cPrevious 

cPrintFileName is the name of the printer peripheral name. 

The starting value is "" (null string).


368.15.103 SETVERB("MARGIN") 

SETVERB( "MARGIN", [nPageOffset] ) ⇒ nPrevious 

nPageOffset is the positive number of column to be used as a left margin for all printer output. 


368.15.104 SETVERB("BELL") 

SETVERB( "BELL", [lBell] ) ⇒ lPrevious 

If lBell is True, the sound of the bell is used to get the attention of the user when some wrong 

actions are made. 


368.15.105 SETVERB("CONFIRM") 

SETVERB( "CONFIRM", [lConfirm] ) ⇒ lPrevious 

If lConfirm is False, the GET is simply terminated typing over the end of the get field; in the 

other case (True), the GET is terminated only pressing an "exit key". The starting value is True. 

368.15.106 SETVERB("ESCAPE") 

SETVERB( "ESCAPE", [lEscape] ) ⇒ lPrevious 

If lEscape is True, the [ Esc ] key is enabled to be a READ exit key, in the other case not. 


The recommended value is True. 

368.15.107 SETVERB("INSERT") 

SETVERB( "INSERT", [lInsert] ) ⇒ lPrevious 

If lInsert is True, the data editing is in INSERT mode, in the other case, it is in OVERWRITE 

mode. 


368.15.108 SETVERB("EXIT") 

SETVERB( "EXIT", [lExit] ) ⇒ lPrevious 

If lExit is True,[Up] and[Down] key may be used as exit key when the cursor is (respectively) 

on the first or on the last GET field. In the other case not. 


The recommended value is False.


368.15.109 SETVERB("INTENSITY") 

SETVERB( "INTENSITY", [lIntensity] ) ⇒ lPrevious 

If lIntensitiy is True, the display of standard and enhanced display colors are enabled. In the 

other case, only standard colors are enabled. 


The recommended value is True. 

368.15.110 SETVERB("SCOREBOARD") 

SETVERB( "SCOREBOARD", [lScoreboard] ) ⇒ lPrevious 

If lScoreboard is True, the display of messages from READ() and MEMOREAD() is allowed; 

in the order case not. 


The recommended value is False: nB do not support scoreboard. 

368.15.111 SETVERB("DELIMITERS") 

SETVERB( "DELIMITERS", [lDelimiters] ) ⇒ lPrevious 

If lDelimiters is True, GET variables appear on the screen delimited with the delimiter symbols. 

In the other case, GET variables are not delimited this way, but only with the use of different 

colors. 


The recommended value is False: the use of delimiters creates one more trouble when designing 

a screen mask. 

368.15.112 SETVERB("DELIMCHARS") 

SETVERB( "DELIMCHARS", [cDelimterCharacters] ) ⇒ cPrevious 

cDelimterCharacters are the delimiter characters used to delimit a GET field when 

SETVERB("DELIMITERS") is True. 

The starting value is "::". 

368.15.113 SETVERB("WRAP") 

SETVERB( "WRAP", [lWrap] ) ⇒ lPrevious 

If lWrap is True, the wrapping of the highlight in MENUs should be active, but this option is 

actually not active and all works as it is False. 

The starting value is False.


368.15.114 SETVERB("MESSAGE") 

SETVERB( "MESSAGE", [nMessageRow] ) ⇒ nPrevious 

nMessageRow is the row number where the @..PROMPT message line should appear on the 

screen. This option is not supported. 


368.15.115 SETVERB("MCENTER") 

SETVERB( "MCENTER", [lMessageCenter] ) ⇒ lPrevious 

If lMessageCenter is True, the @..PROMPT message line should appear centered on the screen. 

This option is not supported. 


368.15.116 STRADDEXTENTION() 

STRADDEXTENTION( cName, cExt ) ⇒ cCompleteName 

cName 

the file name (with or without path) that is probably without 

extention. 

cExt the extention that must be added to cName if it has not one. 

This function check cName for the presence of an extention. It it has not one, cExt will be added. 

368.15.117 STRCUTEXTENTION() 

STRCUTEXTENTION( cName ) ⇒ cName 

cName 

the file name (with or without path) that is probably with extention. 

This function check cName for the presence of an extention. It it has one, the extention is removed. 

368.15.118 STRDRIVE() 

STRDRIVE( cName ) ⇒ cDrive 

cName 

the file name (with or without path) that contains the drive 

letter. 

This function tries to extract the drive letter information from cName.


368.15.119 STREXTENTION() 

STREXTENTION( cName ) ⇒ cExtention 

cName 

the file name (with or without path) that contains an extention. 

This function tries to extract the extention information from cName. 

368.15.120 STRFILE() 

STRFILE( cName ) ⇒ cFileName 

cName 

the file name with or without path. 

This function tries to extract the file name without path from cName. 

368.15.121 STRFILEFIND() 

STRFILEFIND( cName, cPath ) ⇒ cFileName 

cName 

cPath 

the file name or pathname containing the file name to search 

inside the cPath list. 

a list of paths separated with semicolon (just like Dos does), 

where cFile should be searched. 

If your file is to be found on different possible positions, this function search the first place where 

the file is found and returns a valid pathname to that file. 

368.15.122 STRGETLEN() 

STRGETLEN( xExpr, cPicture ) ⇒ nFieldLength 

xExpr a generic expression. 

cPicture 

the picture string. 

This function returns the length of field when using xExpr with cPicture. 

368.15.123 STRLISTASARRAY() 

STRLISTASARRAY( cList, [cDelimiter] ) ⇒ aList 

cList 

cDelimiter 

This function transform a character string list into an array. 

a character string containing a list separated with cDelimiter. 

the delimiter used to separate the elements contained inside 

the list.


368.15.124 STROCCURS() 

STROCCURS( cSearch, cTarget ) ⇒ nOccurrence 

cSearch 

the search string to find inside cTarget. 

cTarget the string to be searched for the presence of cSearch. 

This function returns the number of occurrence that cSearch is contained inside cTarget. 

368.15.125 STRPARENT() 

STRPARENT( cName ) ⇒ cParentPath 

cName 

the pathname. 

This function tries to return a parent path from cName. 

368.15.126 STRPATH() 

STRPATH( cName ) ⇒ cPath 

cName 

the pathname. 

This function tries to extract the path from cName. 

368.15.127 STRTEMPPATH() 

STRTEMPPATH() ⇒ cTempPath 

This function returns a temporary path searching for possible definitions inside the environmental 

variables. 

368.15.128 STRXTOSTRING() 

STRXTOSTRING( xVar, [cType] ) ⇒ cTrasformed_to_string 

xVar 

is the data of any type to be converted into string. 

cType is the type of the data contained inside xVar. 

This function returns xVar transformed into a character string.


368.15.129 TB() 

TB( [nTop], [nLeft], [nBottom], [nRight], 

[acCol], [acColSayPic], 

[acColTopSep], [acColBodySep], [acColBotSep], 

[acColHead], [acColFoot], 

[alColCalc], 

[abColValid], 

[abColMsg], 

[cColor], [abColColors], 

[nFreeze], 

[lModify], 

[lAppend], 

[lDelete], 

[lButtons | aButtons] ) ⇒ NIL 

nTop, nLeft, nBottom, nRight defines the screen area where browse have to take place. 

acCol 

is the columns array to be included into the browse. 

acColSayPic is the picture array. 

acColTopSep is the top separation array: default is chr(194)+chr(196). 

acColBodySep is the body separation array: default is chr(179). 

acColBotSep is the bottom separation array: default is chr(193)+chr(196). 

acColHead 

is the header array for every column. 

acColFoot 

is the footer array for every column. 

alColCalc 

is the array that identify the calculated column (not editable). 

True (‘.T.’) means calculated. 

abColValid 

is the validation array that specify when a field is properly 

filled. The condition must be specified in code block format. 

is the message array that permits to show information at the 

abColMsg 

bottom of browse area. The array must be composed with 

code blocks which result with a character string. 

cColor 

is the color string: it may be longer than the usual 5 elements. 

is the color code block array. The code block receive as pa- 

abColColors 

rameter the value contained inside the field and must return 

an array containing two numbers: they correspond to the two 

color couple from cColor. 

nFreeze 

indicates the number of columns to be left frozen on the left 

side. 

lModify indicates whether the browse can modify data. 

lDelete indicates whether the browse can delete and recall records. 

lButtons 

if True, default buttons are displayed. 

aButtons 

array of buttons. 

aButtons[n][1] N the nth button row position; 

aButtons[n][2] N the nth button column position; 

aButtons[n][3] C the nth button text; 

aButtons[n][4] B the nth button code block. 

This function, called without parameters, starts the browse of the active alias, and if relations are 

established, the browse includes also related data. 

Please note that due to an unresolved problem, the field names contained inside acCol should 

better contain also the alias (ALIAS->FIELD_NAME). See also the examples.


368.15.130 TEXT() 

TEXT( cText ) ⇒ NIL 

Shows the text contained into cText. 

368.15.131 TGLINSERT() 

TGLINSERT() ⇒ NIL 

Toggle the global insert mode and the cursor shape. 

368.15.132 TIMEX2N() 

TIMEX2N( [nHH], [nMM], [nSS] ) ⇒ nTime 

nHH is the number of hours. 

nMM is the number of minutes. 

nSS is the number of seconds. 

This function calculate the "time number" that is a number representing days and/or portion of a 

day: 1 is 1 day or 24 hours, 0.5 is 12 hours, and so on. 

368.15.133 TIMEN2H() 

TIMEN2H( nTime ) ⇒ nHours 

nTime 

is the "time number" that is a number representing days and/or 

portion of a day: 1 is 1 day or 24 hours, 0.5 is 12 hours, and 

so on. 

This function returns the integer number of hours contained inside nTime. 

368.15.134 TIMEN2M() 

TIMEN2M( nTime ) ⇒ nMinutes 

nTime 



so on. 

This function returns the integer number of minutes contained inside nTime after subtracting the 

hours.


368.15.135 TIMEN2S() 

TIMEN2S( nTime ) ⇒ nSeconds 

nTime 



so on. 

This function returns the number of seconds (with eventual decimals) contained inside nTime 

after subtracting the hours and the minutes. 

368.15.136 TRUESETKEY() 

TRUESETLEY( nInkeyCode, bAction ) ⇒ .T. 

This function is equivalent to SETKEY() but it returns always ‘.T.’ 

368.15.137 WAITFILEEVAL() 

WAITFILEEVAL( lClose ) ⇒ .T. 

Shows a wait bar calling WAITPROGRESS() for operation on records of a database. 

If there is no index active, it is equivalent to WAITPROGRES(RECNO()/LASTREC()). 

if an index is active, this cannot work, so an increment for each call is made: WAITPRO- 

GRES((nIncrement++)/LASTREC()). 

This function must be closed calling it with the lClose parameter to true (‘.T.’). This way, 

internal counters are closed and WAITPROGRESS() is closed too. 

368.15.138 WAITFOR() 

WAITFOR( [cMessage] ) ⇒ NIL 

Shows cMessage until it is called again. The wait window is closed when called without parameter 

or with NIL. 

368.15.139 WAITPROGRESS() 

WAITPROGRESS( [nPercent] ) ⇒ .T. 

Shows a wait bar on the screen top depending on the value contained into nPercent. nPercent 

starts form 0 and ends to 1 (100%). If a value of one or more, or NIL is passed, the wait window 

is closed.


368.16 Normal command substitution 

Clipper works only with functions and commands that are converted into function using the 

‘STD.CH’. Here are described some command replacement that can be used also with nB macros. 

? 

@BOX 

@TO 

@GET 

@SAY 

? [exp_list] 

qout([exp_list]) 

?? [exp_list] 

qqout([exp_list]) 

@ nTop, nLeft, nBottom, nRight BOX cnBoxString [COLOR cColorString] 

dispbox(nTop, nLeft, nBottom, nRight, [cnBoxString], [cColorString]) 

@ nTop, nLeft TO nBottom, nRight DOUBLE [COLOR cColorString] 


@ nTop, nLeft TO nBottom, nRight [COLOR cColorString] 


@ nTop, nLeft CLEAR [TO nBottom, nRight] 

scroll([nTop], [nLeft], [nBottom, nRight]) 

setpos(nRow, nCol) 

@ nTop, nLeft GET Var [PICTURE cGetPicture] [COLOR cColorString] [WHEN lPreExpression] ←↪ 

↩→[VALID lPostExpression] 

setpos(nTop, nLeft) 

aadd( GetList, _GET_( Var, "Var", cGetPicture, [{|| lPostExpression}],←↪ 

↩→[{|| lPreExpression}] ):display() ) atail(GetList):colorDisp(cColorString) 

@ nTop, nLeft SAY exp [COLOR cColorString] 


devout(exp [, cColorString]) 

@ nTop, nLeft SAY exp PICTURE cSayPicture [COLOR cColorString] 


devoutpic(exp, cSayPicture, [cColorString]) 

APPEND 

CLEAR 

APPEND BLANK 

dbappend() 

CLEAR 

Scroll() 

SetPos(0,0)


CLOSE 

ReadKill(.T.) 

GetList := {} 

CLEAR GETS 

ReadKill(.T.) 

GetList := {} 

CLEAR SCREEN | CLS 

Scroll() 

SetPos(0,0) 

CLOSE 

dbCloseArea() 

CLOSE idAlias 

idAlias->( dbCloseArea() ) 

CLOSE ALTERNATE 

Set(19, "") 

CLOSE DATABASES 

dbCloseAll() 

CLOSE INDEXES 

dbClearIndex() 

COMMIT 

COMMIT 

COUNT 

dbCommitAll() 

COUNT TO idVar [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {||idVar:=idVar+1}, {||lForCondition}, {||lWhileCondition},←↪ 


DEFAULT 

DEFAULT xVar TO xDefaultValue 

DEFAULT( @xVar, xDefaultValue ) ⇒ xVar 

DELETE 

EJECT 

DELETE 

dbDelete() 

DELETE [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {||dbDelete()}, {||lForCondition}, {||lWhileCondition},←↪ 


DELETE FILE xcFile 


EJECT 

ERASE 

qqout( chr(13) ) 

ERASE xcFile 

ferase( cFile )


FIND 

GO 

FIND xcSearchString 

dbSeek( cSearchString ) 

GO[TO] nRecord 

dbgoto(nRecord) 

GO[TO] BOTTOM 

dbGoBottom() 

GO[TO] TOP 

dbgotop() 

INDEX ON 

READ 

INDEX ON expKey TO xcIndexName [UNIQUE] [FOR lForCondition]←↪ 

↩→[WHILE lWhileCondition] [[EVAL lEvalCondition] [EVERY nRecords]] [ASCENDING| 

DESCENDING] 

ordCondSet( [cForCondition], [bForCondition], , [bWhileCondition],←↪ 

↩→[bEvalCondition], [nRecords], RECNO(), , , , lDescending ) 

ordCreate( cIndexName, , cExpKey, bExpKey, lUnique ) 

READ 


GetList := {} 

READ SAVE 


RECALL 

RECALL 

dbRecall() 

RECALL [FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {||dbRecall()}, {||lForCondition}, {||lWhileCondition},←↪ 


REINDEX 

REINDEX [EVAL lEvalCondition] [EVERY nRecords] 

ordCondSet(, , , , [bEvalCondition], [nRecords], , , , , , , ) 

ordListRebuild() 

RENAME 

RENAME xcOldFile TO xcNewFile 

frename( cOldFile, cNewFile ) 

REPLACE 

REPLACE idField1 WITH exp1 [, idField2 WITH exp2...]←↪ 

↩→[FOR lForCondition] [WHILE lWhileCondition] [NEXT nNextRecords]←↪ 


dbeval( {|| idField1 := exp1 [, idField2 := exp2...]},←↪ 

↩→{||lForCondition}, {||lWhileCondition}, nNextRecords,←↪ 

↩→nRecord, lRest )


REPLACE idField1 WITH exp1 

idField1 := exp1 

RESTORE 

SAVE 

SEEK 

RESTORE SCREEN FROM cScreen 

restscreen( 0, 0, Maxrow(), Maxcol(), cScreen ) 

SAVE SCREEN TO cScreen 

cScreen := savescreen( 0, 0, maxrow(), maxcol() ) 

SEEK expSearch [SOFTSEEK] 

dbSeek( expSearch [, lSoftSeek] ) 

SELECT 

SET 

SELECT xnWorkArea | idAlias 

dbSelectArea( nWorkArea | cIdAlias ) 

SET ALTERNATE TO xcFile [ADDITIVE] 

Set( 19, cFile, lAdditive ) 

SET ALTERNATE ON | OFF | xlToggle 

Set( 18, "ON" | "OFF" | lToggle ) 

SET BELL ON | OFF | xlToggle 


SET COLOR | COLOUR TO (cColorString) 

SetColor( cColorString ) 

SET CONFIRM ON | OFF | xlToggle 


SET CONSOLE ON | OFF | xlToggle 


SET CURSOR ON | OFF | xlToggle 

SetCursor( 1 | 0 | iif( lToggle, 1, 0 ) ) 

SET DATE FORMAT [TO] cDateFormat 

Set( 4, cDateFormat ) 

SET DECIMALS TO 

Set( 3, 0 ) 

SET DECIMALS TO nDecimals 

Set( 3, nDecimals ) 

SET DEFAULT TO 

Set( 7, "" ) 

SET DEFAULT TO xcPathspec 

Set( 7, cPathspec )


SET DELETED ON | OFF | xlToggle 


SET DELIMITERS ON | OFF | xlToggle 


SET DELIMITERS TO [DEFAULT] 

Set( 34, "::" ) 

SET DELIMITERS TO cDelimiters 

Set( 34, cDelimiters ) 

SET DEVICE TO SCREEN | PRINTER 

Set( 20, "SCREEN" | "PRINTER" ) 

SET EPOCH TO nYear 

Set( 5, nYear ) 

SET ESCAPE ON | OFF | xlToggle 


SET EXACT ON | OFF | xlToggle 


SET EXCLUSIVE ON | OFF | xlToggle 


SET FILTER TO 

dbclearfilter() 

SET FILTER TO lCondition 

dbsetfilter( bCondition, cCondition ) 

SET FIXED ON | OFF | xlToggle 


SET INDEX TO [xcIndex [, xcIndex1... ] ] 

ordListClear() 

ordListAdd( cIndex ) 

ordListAdd( cIndex1 ) 

... 

SET INTENSITY ON | OFF | xlToggle 


SET KEY nInkeyCode [TO] 

SetKey( nInkeyCode, NIL ) 

SET KEY nInkeyCode TO [idProcedure] 

SetKey( nInkeyCode, { |p, l, v| idProcedure(p, l, v)} ) 

SET MARGIN TO 

Set( 25, 0 ) 

SET MARGIN TO [nPageOffset] 

Set( 25, nPageOffset ) 

SET MESSAGE TO 

Set( 36, 0 )


SKIP 

STORE 

Set( 37, .F. ) 

SET MESSAGE TO [nRow [CENTER | CENTRE]] 

Set( 36, nRow ) 

Set( 37, lCenter ) 

SET ORDER TO [nIndex] 

ordSetFocus( nIndex ) 

SET PATH TO 

Set( 6, "" ) 

SET PATH TO [xcPathspec [, cPathspec1... ] ] 

Set( 6, cPathspec [, cPathspec1... ] ) 

SET PRINTER ON | OFF | xlToggle 


SET PRINTER TO 

Set( 24, "" ) 

SET PRINTER TO [xcDevice|xcFile [ADDITIVE]] 

Set( 24, cDevice|cFile, lAdditive ) 

SET RELATION TO 

dbclearrelation() 

SET RELATION TO [expKey1 INTO xcAlias1] 

[, [TO] expKey2 INTO xcAlias2...] 

[ADDITIVE] 

if !lAdditive 

dbClearRel() 

end 

dbSetRelation( cAlias1, {|| expKey1}, ["expKey1"] ) 

dbSetRelation( cAlias2, {|| expKey2}, ["expKey1"] ) 

SET SCOREBOARD ON | OFF | xlToggle 


SET SOFTSEEK ON | OFF | xlToggle 


SET TYPEAHEAD TO nKeyboardSise 

Set( 14, nKeyboardSise ) 

SET UNIQUE ON | OFF | xlToggle 


SET WRAP ON | OFF | xlToggle 


SKIP [nRecords] [ALIAS idAlias|nWorkArea] 

[idAlias|nWorkArea -> ]( dbSkip([nRecords]) ) 

STORE value TO variable


SUM 

variable := value 

SUM nExp1 [, nExp2...] TO idVar1 [, idVar2...] [FOR lForCondition]←↪ 

↩→[WHILE lWhileCondition] [NEXT nNextRecords] [RECORD nRecord] [REST] [ALL] 

dbeval( {||idVar1:=idVar1+nExp1 [, idVar2:=idVar2+nExp2...] },←↪ 

↩→{||lForCondition}, {||lWhileCondition}, nNextRecords, nRecord, lRest ) 

UNLOCK 

USE 

UNLOCK 

dbUnlock() 

UNLOCK ALL 

dbUnlockAll() 

USE 

dbclosearea() 

USE [xcDatabase]←↪ 

↩→[INDEX xcIndex1 [, xcIndex2...] [ALIAS xcAlias] [EXCLUSIVE|SHARED] [NEW] [READONLY 

] [VIA cDriver]] 

dbUseArea( [lNewArea], [cDriver], cDatabase, [cAlias], [lShared], [lReadOnly] ) 



... 

368.17 nB command substitution functions 

Inside nB there are many functions made only in substitution to other Clipper commands. 

GET 

aGetList 

SAY 

@ nTop, nLeft GET Var 

[PICTURE cGetPicture] 

[COLOR cColorString] 

[WHEN lPreExpression] 

[VALID lPostExpression] 

Get( @aGetList, 


{ |x| iif( pcount() > 0, Var := x, Var ) } 

[cGetPicture], [cColorString], 

[bPreExpression], [bValid] ) 

@ nTop, nLeft SAY exp 

PICTURE cSayPicture 

[COLOR cColorString] 

Say( nTop, nLeft, cVar, [cSayPicture], [cColorString] ) 

is the get list array that will be increased with this get().


APPEND FROM 

APPEND FROM xcFile 

[FIELDS idField_list] 

[scope] 

[WHILE lCondition] 

[FOR lCondition] 

[VIA xcDriver] 

dbApp( cFileName, [acFields], 



[nRecord], 

[lRest], 

[cDriver] ) 



[scope] 



DELIMITED xcDelimiter 

dbDelim( .f., cFileName, [cDelimiter], [acFields], 


[nNextRecords], [nRecord], [lRest] ) 



[scope] 



SDF 

dbSDF( .f., cFileName, [acFields], 



CONTINUE 

COPY 

CONTINUE 

dbContinue() 

COPY FILE xcSourceFile TO xcTargetFile|xcDevice 

CopyFile( cSourceFile, cTargetFile|cDevice ) 

COPY STRUCTURE [FIELDS idField_list] 

TO xcDatabase 

dbCopyStruct( cDatabase, [acFields] ) 

COPY STRUCTURE EXTENDED 

TO xcExtendedDatabase 

dbCopyXStruct( cExtendedDatabase ) 

COPY TO xcFile 


[scope] 



[VIA xcDriver]


dbCopy( cFileName, [acFields], 



[nRecord], 

[lRest], 

[cDriver] ) 



[scope] 



DELIMITED xcDelimiter 

dbDelim( .t., cFileName, [cDelimiter], [acFields], 





[scope] 



SDF 

dbSDF( .t., cFileName, [acFields], 



CREATE 

JOIN 

CREATE xcDatabase 

FROM xcExtendedDatabase 

[NEW] 

[ALIAS cAlias] 

[VIA cDriver] 

dbOldCreate( cDatabase, cExtendedDatabase, 

[cDriver], [lNew], [cAlias] ) 

JOIN WITH xcAlias TO xcDatabase 

[FOR lCondition] [FIELDS idField_list] 

dbJoin( cAlias, cDatabase, 

[acFields], [bForCondition] ) 

KEYBOARD 

KEYBOARD cString 

Keyboard( [cString] ) ⇒ NIL 

LABEL FORM 

LABEL FORM xcLabel 

[TO PRINTER] 

[TO FILE xcFile] 

[NOCONSOLE] 

[scope] 



[SAMPLE] 

dbLabelForm( cLabel, [lToPrinter], [cFile], 

[lNoConsole], [bForCondition], [bWhileCondition], 

[nNextRecords], [nRecord], [lRest], [lSample] )


LIST 

LIST exp_list 

[TO PRINTER] 


[scope] 



[OFF] 

dbList( [lToDisplay], abListColumns, 

[lAll], 


[nNextRecords], [nRecord], [lRest], 

[lToPrinter], [cFileName] ) 

LOCATE 

PACK 

LOCATE [scope] FOR lCondition 


dbLocate( [bForCondition], [bWhileCondition], 


PACK 

dbPack() 

PUBLIC 

QUIT 

PUBLIC idMemvar 

MemPublic( cMemvarName|acMemvarNames ) 

QUIT 

Quit() 

RELEASE 

RELEASE idMemvar 

MemRelease( cMemvarName|acMemvarNames ) 

REPORT FORM 

REPORT FORM xcReport 

[TO PRINTER] 


[NOCONSOLE] 

[scope] 



[PLAIN | HEADING cHeading] 

[NOEJECT] [SUMMARY] 

RF( cForm, 


[nNext], [nRecord], [lRest], [lPlain], 

[cbHeading], [lBeforeEject], [lSummary], 

[lDate], [acExtra] ) ⇒ NIL 

RESTORE FROM 

RESTORE FROM xcMemFile [ADDITIVE] 

MemRestore( cMemFileName, [lAdditive] )


RUN 

RUN xcCommandLine 

Run( cCommand ) 

SAVE TO 

SAVE TO xcMemFile 

[ALL [LIKE|EXCEPT skeleton]] 

MemSave( cMemFileName, [cSkeleton], [lLike] ) 

SET FUNCTION 

SORT 

TOTAL 

SET FUNCTION nFunctionKey TO cString 

SetFunction( nFunctionKey, cString ) 

SORT TO xcDatabase 

ON idField1 [/[A|D][C]] 

[, idField2 [/[A|D][C]] ...] 

[scope] 



dbSort( cDatabase, [acFields], 



TOTAL ON expKey 

[FIELDS idField_list] TO xcDatabase 

[scope] 



dbTotal( cDatabase, bKey, [acFields, 


[nNextRecords], [nRecord]], [lRest] ) 

UPDATE 

ZAP 

UPDATE FROM xcAlias 

ON expKey [RANDOM] 

REPLACE idField1 WITH exp 

[, idField2 WITH exp ...] 

dbUpdate( cAlias, bKey, [lRandom], [bReplacement] ) 

Example: 

ZAP 

dbZap() 

dbUpdate( "INVOICE", {|| LAST}, .T.,; 

{|| FIELD->TOTAL1 := INVOICE->SUM1,; 

FIELD->TOTAL2 := INVOICE->SUM2 } )


368.18 RPT: the nB print function 

The function RPT() helps to print ASCII file containing Memvars, Fields and print commands. 

RPT() is accessible from the DOC() menu. 

368.18.1 Memvars and fields 

As usual with standard word processors, variables are written delimited with "" (Alt+175). 

Inside these delimiters can find place character Memvars, character Fields and functions giving 

a character result. 

The RPT() function generates a public variable n_Lines that contains the available lines inside 

the actual sheet. Every time a line is written, this value is reduced, until a new page is reached and 

then it will start again from the maximum value. It is useful to read this variable to determinate 

if there is enough space or it is better to change page. 

368.18.2 Commands 

The function RPT() recognise some print commands. These commands starts with the asterisk 

(*) symbol. This means that "*" is a print command prefix. 

It follows the command syntax. 

*COMMAND 

*COMMAND 

cStatement 

cStatement 

... 

*END 

The lines contained inside *COMMAND - *END are executed with the nB macro interpreter. 

*DBSKIP 

*DBSKIP [nSkip] 

It Executes a dbskip() on the active alias. 

*FOOT 

*FOOT 

cFooter 

cFooter 

... 

*END 

The lines contained inside *FOOT - *END are printed each time at the bottom of pages. 

*HEAD 

*HEAD 

cHeader 

cHeader 

... 

*END 

The lines contained inside *HEAD - *END are printed each time at the top of pages.


*IF 

*IF lCondition 

... 

... 

*END 

If the condition lCondition is true, the lines contained inside *IF - *END are printed. 

*INSERT 

*LEFT 

*LPP 

*INSERT cFileName 

Includes the text contained into the file cFileName. 

*LEFT nLeftBorder 

The nLeftBorder is the number of column to be left blank as a left border. 

*LPP nLinesPerPage 

It determinates the page length expressed in lines. After printing the nLinesPerPageth line, 

a form feed is sent. 

*NEED 

*PA 

*NEED nLinesNeeded 

If the available lines are less then nLinesNeeded, the follwing text will be printed on the 

next page. 

*PA 

*REM 

Jumps to a new page. 

*REM | *COMMENT [comment_line] 

It adds a comment that will not be printed. 

*WHILE 

*WHILE lCondition 

... 

... 

*END 

The lines contained inside *WHILE - *END are printed as long as lCondition is true. 

368.18.3 Examples 

It follows some example of text to be printed with the RPT() function. Example’s lines are numbered. 

Line numbers must not be part of a real RPT text files. 

PAGE DEFINITION 

Margins are defined with *HEAD, *FOOT and *LEFT commands. In the following example 

is defined:


Top 2 lines; 

Bottom 2 lines; 

Left 10 characters. 

The right margin is not defined as it depends on the lines length that will be printed. 

The only considered page dimension is the height, *LPP (lines per page): 

Page height 66 lines. 

Here starts the example: 

001 *lpp 66 

002 *head 

003 

004 

005 *end 

006 *foot 

007 

008 

009 *end 

010 *left 10 

011 ... text text text 

012 ... test text text 

... 

At line 001 is defined the page height in lines. At line 002 is defined the header; it contains 

two empty lines (003 and 004) which will be printed at the top of every page. At line 006 

starts the footer definition that contains two empty lines (007 and 008) that will be printed 

at the end of every page. At line 010 is defined the space on the left that will be added to 

every line printed. From line 011 starts the normal text. 

HEADER AND FOOTER 

The commands *HEAD and *FOOT are used to define the top and bottom border if they 

contains empty lines, it these lines are not empty, they became real head and foot. 

The dimensions are as it follows: 

Top 6 lines (should be one inch); 

Bottom 6 lines; 

Left 10 characters (should be an inch). 

Page height 66 lines (should be 11 inch). 

At position 0.5 in (after 3 lines) a one line header appears.


001 *lpp 66 

002 *head 

003 

004 

005 

006 ------------------- MYFILE.TXT ------------------- 

007 

008 

009 *end 

010 *foot 

011 

012 

013 

014 

015 

016 

017 *end 

018 *left 10 



... 

At line 006 (the fourth header line) a text appears. It will be printed on every page at the 

absolute fourth page line. 

CODE INSERTION 

Pieces of code can be inserted inside *COMMAND - *END. It can be useful to make 

complicated reports. 

The following example declares a public variable used to number pages. 

001 *command 

002 mempublic("PageNo") 

003 PageNo := 0 

004 *end 

005 *lpp 66 

006 *head 

007 *command 

008 PageNo := PageNo +1 

009 *end 

010 

011 

012 *end 

013 *foot 

014 

015 Page 

016 

017 *end 

018 *left 10 



... 

At line 001 starts a *COMMAND definition: lines 002 and 003 will be interpreted from the 

function EX(), the nB interpreter. These lines define a public variable and initialize it at 0. 

This variable will be use to count pages. 

At line 007, inside the header (nested), start another *COMMAND definition that contains 

an increment for the "PageNo" variable. As the header is read and "executed" for every new 

page, and that before the footer, the variable "PageNo" will contain the right page number. 

At line 015, inside the footer, a reference to "PageNo" appears. Here will be printed the 

page number. 

A more complicated example can be found in ‘ADDRESS.TXT’ the RPT text file used for 

the ADDRESS.& macro examples.


368.19 How can I... 

nB is a little bit complicated as it may do many things. Here are some examples. 

Create a UDF function 

UDF means User Defined Function. Inside nB there isn’t the possibility to create functions, 

but there is an alternative: code blocks. 

Create a big code block 

A code block cannot be longer than 254 characters, as any other instruction inside nB. 

So, there is no way to make a bigger code block, but a code block can call another code 

block, and so on. For example: 

mempublic( { "first", "second", "third" } ) 

first := {|| eval( second, "hello" ) } 

second := {|x| eval( third, x ) } 

third := {|x| alertbox( x ) } 

eval( first ) 

This stupid example simply will show the alert box containing the word "hello". 

368.20 The source files 

The nB source is composed of four files: 

‘NB.PRG’ The main source file containing essentially the nB menu. 

‘REQUEST.PRG’ Contains a link to all Clipper standard functions. 

‘STANDARD.PRG’ Contains the most important standard functions. 

‘EXTRA.PRG’ 

Contains some extra function not absolutely necessary during 

macro execution. 

The file ‘REQUEST.PRG’ source file generates some warnings because not all functions listed 

there are directly called form nB. Don’t worry about that warning message. 

Different ‘.RMK’ (rmake) files are included to compile nB differently, including/excluding some 

program parts, for example to obtain a runtime executor.

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