if (sigprocmask (0, NULL, &set) < 0
if (__sigprocmask (0, NULL, &set) < 0
__sigpause (sig_or_mask, is_sig)     int sig_or_mask;     int is_sig;{  sigset_t set;  int sig;  if (is_sig != 0)    {      /* The modern X/Open implementation is requested.  */      if (sigprocmask (0, NULL, &set) < 0	  /* Yes, we call `sigdelset' and not `__sigdelset'.  */	  || sigdelset (&set, sig_or_mask) < 0)	return -1;    }  else    {      if (__sigemptyset (&set) < 0)	return -1;      if (sizeof (sig_or_mask) == sizeof (set))	*(int *) &set = sig_or_mask;      else if (sizeof (unsigned long int) == sizeof (set))	*(unsigned long int *) &set = (unsigned int) sig_or_mask;      else	for (sig = 1; sig < NSIG; ++sig)	  if ((sig_or_mask & sigmask (sig)) && __sigaddset (&set, sig) < 0)	    return -1;    }  return sigsuspend (&set);}