Advanced Techniques

Using SUBSET Operator

For removing header and trailer while preserving specific patterns:

//STEP1    EXEC PGM=ICETOOL
//TOOLMSG  DD SYSOUT=*
//DFSMSG   DD SYSOUT=*
//IN       DD DSN=INPUT.FILE,DISP=SHR
//OUT      DD DSN=OUTPUT.FILE,DISP=(NEW,CATLG,DELETE)
//TOOLIN   DD *
  SUBSET FROM(IN) TO(OUT) INPUT REMOVECC
/*

Handling Multiple Headers and Trailers

When dealing with multiple header/trailer pairs in a single file:

//STEP1    EXEC PGM=SORT
//SYSOUT   DD SYSOUT=*
//SORTIN   DD DSN=INPUT.FILE,DISP=SHR
//SORTOUT  DD DSN=OUTPUT.FILE,DISP=(NEW,CATLG,DELETE)
//SYSIN    DD *
  OPTION EQUALS
  INREC IFTHEN=(WHEN=INIT,OVERLAY=(100:SEQNUM,8,ZD)),
        IFTHEN=(WHEN=(1,4,CH,EQ,C'0000'),
                OVERLAY=(108:C'HEADER')),
        IFTHEN=(WHEN=(1,4,CH,EQ,C'9999'),
                OVERLAY=(108:C'TRAILER')),
        IFTHEN=(WHEN=(1,4,CH,EQ,C'0100'),
                OVERLAY=(108:C'DETAIL'))
  SORT FIELDS=(108,7,CH,A,100,8,ZD,A)
/*

SKIPREC and STOPAFT Techniques

Basic Header/Trailer Removal

To skip the first record (header) and stop before the last record (trailer):

//STEP1    EXEC PGM=SORT
//SYSOUT   DD SYSOUT=*
//SORTIN   DD DSN=INPUT.FILE,DISP=SHR
//SORTOUT  DD DSN=OUTPUT.FILE,DISP=(NEW,CATLG,DELETE)
//SYSIN    DD *
  SORT FIELDS=(1,10,CH,A)
  SKIPREC=1
/*
//* Note: STOPAFT requires knowing exact record count

Dynamic Last Record Calculation

For dynamic trailer handling:

//STEP0100 EXEC PGM=SORT
//SYSOUT   DD SYSOUT=*
//SORTIN   DD DSN=INPUT.FILE,DISP=SHR
//SORTOUT  DD DSN=&T1,DISP=(,PASS),SPACE=(TRK,(1,1),RLSE)
//SYSIN    DD *
  OPTION SKIPREC=1
  SORT FIELDS=COPY
  OUTREC FIELDS=(SEQNUM,8,ZD,START=0,INCR=1,80:X)
  OUTFIL NODETAIL,REMOVECC,
         TRAILER1=(C' OPTION COPY,SKIPREC=1,STOPAFT=',1,8,80:X)
/*

//STEP0200 EXEC PGM=SORT
//SYSOUT DD SYSOUT=*
//SORTIN DD DSN=INPUT.FILE,DISP=SHR
//SORTOUT DD SYSOUT=*
//SYSIN DD DSN=&T1,DISP=OLD
/*

OUTFIL Header and Trailer Techniques

Adding Headers and Trailers to Output

//STEP1    EXEC PGM=SORT
//SYSOUT   DD SYSOUT=*
//SORTIN   DD DSN=INPUT.FILE,DISP=SHR
//SORTOUT  DD DSN=OUTPUT.FILE,DISP=(NEW,CATLG,DELETE)
//SYSIN    DD *
  SORT FIELDS=(1,10,CH,A)
  OUTFIL FNAMES=SORTOUT,
         HEADER1=C'HEADER RECORD - SORTED DATA',
         TRAILER1=(C'TRAILER - TOTAL RECORDS: ',COUNT=(M11,LENGTH=8))
/*

Multiple Output Files with Different Headers

//STEP1    EXEC PGM=SORT
//SYSOUT   DD SYSOUT=*
//SORTIN   DD DSN=INPUT.FILE,DISP=SHR
//OUT1     DD DSN=OUTPUT1.FILE,DISP=(NEW,CATLG,DELETE)
//OUT2     DD DSN=OUTPUT2.FILE,DISP=(NEW,CATLG,DELETE)
//SYSIN    DD *
  SORT FIELDS=(1,10,CH,A)
  OUTFIL FNAMES=OUT1,
         INCLUDE=(20,1,CH,EQ,C'A'),
         HEADER1=C'TYPE A RECORDS',
         TRAILER1=(C'A-TYPE COUNT: ',COUNT)
  OUTFIL FNAMES=OUT2,
         INCLUDE=(20,1,CH,EQ,C'B'),
         HEADER1=C'TYPE B RECORDS',
         TRAILER1=(C'B-TYPE COUNT: ',COUNT)
/*

Best Practices and Tips

1. Always Use EQUALS Option

When preserving header/trailer order is critical:

OPTION EQUALS

2. Validate Record Counts

Always verify trailer record counts match detail records:

OUTFIL TRAILER1=(C'DETAIL COUNT: ',COUNT=(M11,LENGTH=8))

3. Handle Variable Length Records

For VB files, account for RDW in position calculations:

INREC IFTHEN=(WHEN=(5,6,CH,EQ,C'HEADER'),OVERLAY=(85:C'H'))

4. Test with Small Datasets

Always test complex header/trailer logic with small, known datasets before production.

5. Document Record Layouts

Clearly document the structure and position of identifiers:

• Position 1-6: Record Type (HEADER/DETAIL/TRAILER)
• Position 7-14: Date (YYYYMMDD)
• Position 15-22: Control Number
• Error Handling and Validation

Validate Header/Trailer Presence

//STEP1    EXEC PGM=ICETOOL
//TOOLMSG  DD SYSOUT=*
//DFSMSG   DD SYSOUT=*
//IN       DD DSN=INPUT.FILE,DISP=SHR
//TOOLIN   DD *
  COUNT FROM(IN) FIRST 1 LAST 1 USING(CTL1)
/*
//CTL1CNTL DD *
  INCLUDE COND=(1,6,CH,EQ,C'HEADER',OR,1,7,CH,EQ,C'TRAILER')
/*

Check for Missing Records

OUTFIL FNAMES=ERRORS,
       INCLUDE=(1,6,CH,NE,C'HEADER',AND,1,6,CH,NE,C'DETAIL',
               AND,1,7,CH,NE,C'TRAILER')