sigsetmask(2)
NAME
sigsetmask − set current signal mask
SYNTAX
sigsetmask(mask);
int mask;
DESCRIPTION
The sigsetmask system call sets the current signal mask (those signals which are blocked from delivery). Signal i is blocked if the i-th bit in mask is a 1.
The system quietly disallows SIGKILL, SIGSTOP, or SIGCONT to be blocked.
The previous set of masked signals is returned.