CRTL, sigpending, Description
*Conan The Librarian
This function stores the set of signals that are blocked from delivery and pending to the calling process in the location pointed to by the set argument. Call either the sigemptyset or the sigfillset function at least once for each object of type sigset_t prior to any other use of that object. If you do not initialize an object in this way and supply an argument to the sigpending function, the result is undefined. See sigemptyset, and sigfillset.