Sharing files between programs (external files)
To
enable separately compiled programs or methods in a run unit to access a file as
a common file, use the EXTERNAL clause for the file.
It is recommended that you follow these guidelines:
- Use the same data-name in the FILE STATUS clause of all the
programs that check the file status code.
- For each program that checks the same file status field, code the EXTERNAL
clause on the level-01 data definition for the file status field.
Using an external file has these benefits:
- Even though the main program does not contain any input or output
statements, it can reference the record area of the file.
- Each subprogram can control a single input or output function, such as OPEN
or READ.
- Each program has access to the file.
Example: using external files
related tasks
Using data in input and output operations
related references
EXTERNAL clause
(COBOL for Windows Language Reference)
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