TOPS-20 PASCAL Language Manual - Bitsavers

I~PUT
AND OUTPUT
7.2.1 Fixed-Length Records
When you specify fixed-length records, you ~re specifying that all
records in the file contain the same number of bytes. A file opened
for direct access must cont3in fixed-length records to allow the
record location to be computed correctly. All binary files (that is,
all files except TEXT files) must have fixed-length records. P~SCAL
does not support binary files with variable-length records.
7.2.2 Variable-Length Records
Variable-length records can contain any nUffiber of byt~s up to the
buffer size specified when the file was opened. TEXT files must have
variable-length records. PASCAL does not support TEXT files with
fixed-length rec~rds.
7.3 THE CLOSE PROCEDURE
The CLOSE procedure closes an open file.
Fo rma t.
CLOSE (file variable);
where:
file variable
specifies the file to be closed.
Execut.ion of this procedure causes the system to close t.he file. Each
file is automatically closed upon exit from the procedure in which it
is declared, except those which have been dynamically allocated with
the procedure NEW. These files should be explicitly closed; if not,
they are automatically closed when the program ends, or when they are
DISPOSED.
You can close only files that have been opened explicitly with the
OPEN procedure or implicitly by the RESET or REWRITE procedure.
Therefore, you cannot close the predeclared file variables INPUT and
OUTPUT.
Example
CLOSE (AlbulTls);
This procedure closes the file Albums to further access, and deletes
the file if it is internal to the current program.
7.4 THE FIND PROCEDURE
The FIND procedure positions a file pointer at a
in the file.
specified component
Fo rma t
FIND (file variable, integer expression);
7-4