| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
| z/OS® UNIX | both |
#include <unistd.h>
int __isPosixOn(void);The __isPosixOn() function returns 1 if the kernel is active and the POSIX runtime option is in effect for the calling process.
The __isPosixOn() function returns 1 if the POSIX runtime option is in effect for the calling process and returns 0 otherwise.
If POSIX is in effect, then the kernel is active, although the kernel may be active without POSIX being in effect.
There are no errno values defined.