Coding the input procedure

You can use an input procedure to:

• Release data items to the sort file from WORKING-STORAGE or LOCAL-STORAGE.
• Release records that have already been read elsewhere in the program.
• Read records from an input file, select or process them, and release them to the sort file.

Each input procedure must be contained in either paragraphs or sections. For example, to release records from a table in WORKING-STORAGE or LOCAL-STORAGE to the sort file SORT-WORK-2, you could code as follows:

    SORT SORT-WORK-2
      ON ASCENDING KEY SORT-KEY
      INPUT PROCEDURE 600-SORT3-INPUT-PROC
    . . .
600-SORT3-INPUT-PROC SECTION.
    PERFORM WITH TEST AFTER
      VARYING X1 FROM 1 BY 1 UNTIL X1 = 100
      RELEASE SORT-WORK-2-AREA FROM TABLE-ENTRY (X1)
    END-PERFORM.

To transfer records to the sort program, all input procedures must contain at least one RELEASE or RELEASE FROM statement. To release A from X, for example, you can code:

MOVE X TO A.
RELEASE A.

Alternatively, you can code:

RELEASE A FROM X.

The following table compares the RELEASE and RELEASE FROM statements.

MOVE SORT-EXT-RECORD
  TO SORT-RECORD
PERFORM RELEASE-SORT-RECORD
. . .
RELEASE-SORT-RECORD.
  RELEASE SORT-RECORD

PERFORM RELEASE-SORT-RECORD
. . .
RELEASE-SORT-RECORD.
  RELEASE SORT-RECORD
    FROM SORT-EXT-RECORD