Varying the input or output file at run time
The file-name that you code in a SELECT
clause
is used as a constant throughout your COBOL program, but you can associate
the name of that file with a different system file at run time.
About this task
Changing a file-name within a COBOL program would require
changing the input statements and output statements and recompiling
the program. Alternatively, you can change the assignment-name in the export
command
to use a different file at run time.
Environment variable
values that are in effect at the time of the OPEN
statement
are used for associating COBOL file-names to the system file-names
(including any path specifications).