github.com/afumu/libc@v0.0.6/musl/src/signal/sigismember.c (about)

     1  #include <signal.h>
     2  
     3  int sigismember(const sigset_t *set, int sig)
     4  {
     5  	unsigned s = sig-1;
     6  	if (s >= _NSIG-1) return 0;
     7  	return !!(set->__bits[s/8/sizeof *set->__bits] & 1UL<<(s&8*sizeof *set->__bits-1));
     8  }