OPEN

Function

OPEN opens file for I/O

Syntax

OPEN “file name” FOR {OUTPUT|APPEND|INPUT} AS file no.

Example

10 OPEN "OUTFIL.TXT" FOR OUTPUT AS 1

This will open the file “OUTFIL.TXT” for output from a Basic program as file number one.

10 OPEN "APPEND.TXT" FOR APPEND AS 3

This opens the file “APPEND.TXT” as file number three. Any data written to the file will be appended. MAXFILES must have previously been set to a minimum of three.

10 OPEN "INPUT.TXT" FOR INPUT AS 4

The file is opened for input as file number four, this will allow the data in the file to be read by a Basic program.

Remarks

When a file is OPENed HUNTER’S firmware automatically performs a checksum generation on the file and compares it to a value stored in the file directory, when the file was last CLOSEd. Any inconsistency will result in a ‘DSK ERROR’ being returned to the user.

The OPEN statement parameter FOR has three options OUTPUT, APPEND and INPUT, they perform the following functions:

OUTPUT

This will open a file for output. Any data that is in the file will be lost.

APPEND

This will also open a file for output, but any data that is output to the file will be added to the end of the data that is already present.

INPUT

The file is opened for input. This will allow a Basic program to read data from the file.

The file number cannot be greater than the number specified in MAXFILES. If MAXFILES 3 has been specified the file number cannot be greater than three.