E35 user exit: changing records

If you write your E35 user exit in COBOL, see COBOL user exit routines and COBOL E35 user exit: changing records.

The EXITCK option affects the way DFSORT interprets certain return codes from user exit E35. To avoid ambiguity, this section assumes that the IBM default, EXITCK=STRONG, was selected at your site. For complete details of the meaning of E35 return codes in various situations with EXITCK=STRONG and EXITCK=WEAK, see E15/E35 return codes and EXITCK.

DFSORT enters the E35 user exit routine each time it prepares to place a record in the output area.

See Figure 1 for logic flow details.

Some uses for the E35 user exit are:

Adding records for output data sets
Omitting records for output data sets
Changing records for output data sets

Note:

If your E35 user exit is processing variable-length records, include a 4-byte RDW at the beginning of each record you change or insert, before you pass it back to DFSORT. The format of an RDW is described in z/OS DFSMS Using Data Sets or System Programming Reference. (Alternatively, you can pad records to the maximum length and process them as fixed-length.)
DFSORT uses the specified or defaulted value for L3 in the RECORD statement to determine the length of the records your E35 user exit passes back to DFSORT. For fixed-length records, be sure that the length of each record your E35 user exit changes or inserts corresponds to the specified or defaulted L3 value. For variable-length records, be sure that the RDW of each record your E35 user exit changes or inserts indicates a length that is less than or equal to the specified or defaulted L3 value. Unwanted truncation or abends may occur if DFSORT uses the wrong length for the records passed to it by your E35 user exit.
For details of the L3 value, see RECORD control statement.
If you use the E35 user exit to dispose of all your output records, you can omit the SORTOUT DD statement.
If you invoke DFSORT from a program and you pass the address of your E35 user exit in the parameter list:
- DFSORT ignores the SORTOUT data set (but not any OUTFIL data sets).
- DFSORT terminates if you specify E35 in a MODS statement.
If you omit the SORTOUT DD statement or it is ignored, and you do not specify any OUTFIL data sets, your E35 user exit routine must dispose of each output record and return to DFSORT with a return code of 4. When DFSORT returns to your routine after you have disposed of the last record, return to DFSORT with a return code of 8 to indicate"do not return."
Remember that if input records are variable-length from a VSAM data set, they will have been prefixed by a 4-byte RDW.
After records have been put into the output area, their lengths cannot be increased.
For a merge application, records deleted by an E35 user exit routine are not sequence-checked. If you use an E35 user exit routine without an output data set, sequence checking is not performed. In this case, you must ensure that the records are sequenced correctly.