sighold.c\signal\src - musl - musl - an implementation of the standard library for Linux-based systems

#include <signal.h>
int sighold(int sig)
{
	sigset_t mask;
	sigemptyset(&mask);
	if (sigaddset(&mask, sig) < 0) return -1;
	return sigprocmask(SIG_BLOCK, &mask, 0);
}