#include <signal.h> int sigpending(sigset_t *set);
The sigpending() function retrieves those signals that have been sent to the calling process but are being blocked from delivery by the calling process's signal mask. The signals are stored in the space pointed to by the set argument.
Upon successful completion, 0 is returned. Otherwise, −1 is returned and errno is set to indicate the error.
The sigpending() function will fail if:
The set argument points to an illegal address.
See attributes(5) for descriptions of the following attributes: