A brief introduction to the operation method of initial, adding and removing process signals in C language _c language

C language Sigemptyset () function: Initializing a signal set
header file:

#include <signal.h>

To define a 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.

C language Sigaddset () function: Add a signal to the signal set
header file:

#include <signal.h>

To define a function:

int Sigaddset (sigset_t *set, int signum);

Function Description: Sigaddset () is used to add the signal represented by the parameter Signum to the parameter set signal set.

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

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

C language Sigdelset () function: Remove a signal from a signal set
header file:

#include <signal.h>

To define a function:

int Sigdelset (sigset_t * set, int signum);

Function Description: Sigdelset () is used to remove the signal represented by the parameter Signum from the set of parameters set.

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

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