The related operation function of process signal set in C language _c language

C language Sigismember () function: test whether a signal has been added to the signal
header files: #include <signal.h>

Definition function: int sigismember (const sigset_t *set, int signum);

Function Description: Sigismember () is used to test whether the signal represented by the parameter Signum has been added to the parameter set signal set. Returns 1 if the signal is already in the signal set, or 0.

Return value: The signal set already has this signal to return 1, no to return 0. If there is an error, return-1.

Error code:
1, efault parameter set pointer address cannot be accessed.
2, the einval parameter Signum not the legal signal number.

C language Sigfillset () function: Add all signals to the signal set
header files: #include <signal.h>

Definition function: int sigfillset (sigset_t * set);

Function Description: Sigfillset () is used to initialize the set of parameter sets, and then all the signals are added to this signal set.

Return value: Returns 0 if the execution succeeds, or 1 if there is an error.

Additional Note: The Efault parameter set pointer address cannot be accessed.

C language Sigemptyset () function: Initializing a signal set
header files: #include <signal.h>

Definition function: int sigemptyset (sigset_t *set);

Function Description: Sigemptyset () is used to initialize the parameter set signal set and empty it.

Return value: Returns 0 if the execution succeeds, or 1 if there is an error.

Error code: Efault parameter Set pointer address cannot be accessed.