Special Usage Considerations › Dynamically Invoking JCLNeat › Using Input-Output Exits with JCLNeat

Using Input-Output Exits with JCLNeat

Any user program invoking JCLNeat can supply its own input and output routines. See the JCLNeat calling parameter list (2, 3, and 4) in the previous section.

When you provide an exit routine for a given ddname, the associated file is not opened, and a DD statement is not required. Instead, the address provided is inserted in the DCB in place of the IBM GET or PUT routines. In this way, JCLNeat always calls your routines for input or output services.

The SEQIN exit is entered whenever a job stream JCL statement is required. The SEQIN exit routine must place the address of the returned statement in R1 and return to JCLNeat using R14. When the exit routine returns end-of-file to JCLNeat, it must return to JCLNeat using R14 plus 4.

The SEQOUT and SYSPRINT exits are entered with R1 pointing to the record that is the output. The length of that record is 133 bytes for file SYSPRINT, and 80 bytes for file SEQOUT. The exit routine is responsible for the disposition of the print line records. The SYSPRINT and SEQOUT exit routines should always return to JCLNeat using R14.