TOPS-20 PASCAL Language Manual - Bitsavers

PROGRAM HEADING AND DECL~RATION
SECTION
4.1 THE PROGRAM HEADING
The program heading begins the PASCAL program. It gives the program a
name and lists the external file variables the program uses.
Format
[fOVERLAID1] PROGRAM program name [(filename [,filename••• ] )]
where:
[OVERLAIDl
specifies that
variables with
Section G.8.
the program can share global
separately compiled modules. See
program name
specifies the name of the program;
six characters are significant.
only the first
filename
specifies the identifier associated
external fiJe that the program uses.
with
an
The program name appears only in the heading and has no other purpose
within the program. The program name cannot be redefined at program
level.
The file names listed in the program heading correspond to the
external files that the program uses. The heading must include the
names of all the external file variables. The predeclared text file
variables INPUT and OUTPUT, by default, refer to your terminal (in
interactive mode) or the batch input and log files (in batch mode).
You must declare file variables for all other external files in the
main program declaration section, and specify those variables in the
program heading. Refer to Chapter 7 for more information on files.
Example I
PROGRAM Test1;
The program heading names the program Testl, but omits the file
variable list. This program does not use the terminal or any external
file.
Example 2
PROGRAM Sauares (INPUT, OUTPUT);
The program heading names the program Squares and specifies the
predeclared file variables INPUT and OUTPUT.
Example 3
PROGRAM Pa~roll (EmploYee, Salar~, Output);
The program heading names the program Payroll and specifies the
external file variables Employee, Salary, and Output.
4-2