Unless I am thick and my brain isn't working, are you both getting the correct results? I mean shouldn't you be incrementing the seqnum for every 50 records within the key?? Lets say for example you have a key ABC and you have 168 records of ABC. So key 51,101 & 151 should be 2,3,4 . with your code , the first set is 50 and the next sets are 51 ,52... and so on.
Run the following test data as sample with your control cards and check the records 51,101,151,152 .... within each key.
//STEP0050 EXEC PGM=SORT
//SYSOUT DD SYSOUT=*
//SORTIN DD *
ABC
DEF
EFG
//SORTOUT DD DSN=&&IN,DISP=(,PASS),SPACE=(CYL,(1,1),RLSE)
//SYSIN DD *
SORT FIELDS=COPY
OUTFIL REPEAT=168
//*
//SYSOUT DD SYSOUT=*
//SORTIN DD *
ABC
DEF
EFG
//SORTOUT DD DSN=&&IN,DISP=(,PASS),SPACE=(CYL,(1,1),RLSE)
//SYSIN DD *
SORT FIELDS=COPY
OUTFIL REPEAT=168
//*
The following control cards will give you the sequence number with increment for every 50 records within the key. You don't even need IFTHEN. The trick here is to start the seqnum with the value we want to divide with. In this case it is 50. so start the seqnum with 50.
//SYSIN DD *
SORT FIELDS=COPY
INREC OVERLAY=(10:SEQNUM,5,FS,START=50,RESTART=(1,3),
10:10,5,FS,DIV,+50,FS,LENGTH=5)
//*
SORT FIELDS=COPY
INREC OVERLAY=(10:SEQNUM,5,FS,START=50,RESTART=(1,3),
10:10,5,FS,DIV,+50,FS,LENGTH=5)
//*
