How do you sort in a COBOL program Give sort file definition, sort statement syntax and meaning ?
Syntax SORT file-1 ON ASCENDINGDESCENDING KEY key…. USING file-2 GIVING file-3.
USING can be substituted by INPUT PROCEDURE IS para-1 THRU para-2
GIVING can be substituted by OUTPUT PROCEDURE IS para-1 THRU para-2.
file-1 is the sort (work) file and must be described using SD entry in FILE SECTION.
file-2 is the input file for the SORT and must be described using an FD entry in FILE SECTION and SELECT
clause in FILE CONTROL.
file-3 is the out file from the SORT and must be described using an FD entry in FILE SECTION and SELECT
clause in FILE CONTROL.
file-1, file-2 & file-3 should not be opened explicitly.
INPUT PROCEDURE is executed before the sort and records must be RELEASEd to the sort work file from the input procedure.
OUTPUT PROCEDURE is executed after all records have been sorted. Records from the sort work file must be RETURNed one at a time to the output procedure.