IBM SC33-1683-02 - Manual (Page 107)

KEYLENGTH
REQID
SYSID
The following are always output fields:
INTO
NUMREC
SET
Whether LENGTH and RIDFLD are input or output fields depends on the request,
as shown in Table 4. A dash (—) means that the keyword cannot be specified on
the request.
Table 4. LENGTH and RIDFLD as input and output fields
Request LENGTH RIDFLD
READ Output See Note 1.
WRITE Input See Note 2.
REWRITE Input —
DELETE — See Note 3.
UNLOCK — —
STARTBR — Input
READNEXT Output Output
READPREV Output Output
ENDBR — —
RESETBR — Input
Notes:
1. Normally, this is an input field. However, if UPDATE is specified and the file is a
BDAM file using extended key search, RIDFLD is used for both input and
output.
2. The use of RIDFLD on a WRITE request depends on the file type. For a VSAM
KSDS or RRDS, or a fixed-format BDAM file, RIDFLD is an input field. For all
other file types, it is used either for output only, or for both input and output, and
should be treated like an output field.
3. RIDFLD is an input field on DELETE requests that are not preceded by a READ
UPDATE. It is not specified on requests that are preceded by a READ UPDATE.
Modifying input fields
The correct method of modifying an input field is to create a new copy of it, and to
change the address in the command-level parameter list to point to your new data.
Note: You must never modify an input field by altering the data that is pointed to by
the command-level parameter list. To do so would corrupt storage belonging
to the application program and would cause a failure when the program
attempted to reuse the field.
file control EXEC interface API exits
Chapter 1. Global user exit programs 75