All z/OS® UNIX System
Services C functions are available at all times. In some situations,
you must specify the POSIX(ON) runtime option. This is required for
the POSIX.4a threading functions, the POSIX system() function,
and signal handling functions where the behavior is different between
POSIX/XPG4 and ISO. Refer to z/OS XL C/C++ Runtime Library Reference for
more information about requirements for each function.
You can invoke a
z/OS XL C/C++ program that uses
z/OS UNIX C
functions using the following methods:
- Directly from a shell.
- From another program, or from a shell, using one of the exec family
of functions, or the BPXBATCH utility from TSO or MVS™ batch.
- Using the POSIX system() call.
- Directly through TSO or MVS batch
without the use of the intermediate BPXBATCH utility. In some cases,
you may require the POSIX(ON) runtime option.