The z/OS UNIX REXX functions extend the REXX language on z/OS® when it is used in the z/OS UNIX REXX environment. Except for bpxwunix() and syscalls(), these functions must be run in a z/OS UNIX environment. The z/OS UNIX REXX functions include functions for standard REXX I/O, and for accessing common file services and environment variables.

All of the functions are fully enabled for large files (>2 GB).

All numbers that are used as input on the functions must be integers. The default precision for REXX is 9 digits. If arithmetic is used on large numbers, be sure to change your precision appropriately, using the NUMERIC DIGITS statement.