R-OPEN-FUNCTION

This function opens an existing relative file. If it is successful, the value in RETURN-CODE should be moved to a data item that is USAGE HANDLE. This data item is passed as the open file handle to the other file handling functions.

If it fails, RETURN-CODE is set to ZERO.

This function only opens already existing files. If the file does not exist, the function fails, even when opening for output.

Syntax:

SET R-OPEN-FUNCTION TO TRUE    CALL "R$IO" USING RIO-FUNCTION                    name                    mode                     maxSize                    minSize             GIVING returnCode

Parameters:

name	the name of the file to open.
mode	one of the following values (defined in isfilesys.def):
	Finput Foutput Fio Fextend	Open for input only. Open for output only. Open for input and output. Same as Foutput.
	mode may also have one of the following flags (defined in isfilesys.def) added to it to indicate file locking options:
	Fread_lock Fwrite_lock Fmass_update	Locks file against other updaters. Locks file against all others. Same as Fwrite_lock.
maxSize	the maximum record size.
minSize	the minimum record size. It should be equal to max-size, since relative files can’t be variable lenght.

Return code:

returnCode can be any signed numeric data item and provides additional information:

>0	File handle.
0	Operation failed.