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/*
* signals.c -- general signals interface for nmh
*
* $Id: signals.c,v 1.1.1.1 1999/04/30 18:08:34 doug Exp $
*/
#include <h/mh.h>
#include <h/signals.h>
int
SIGPROCMASK (int how, const sigset_t *set, sigset_t *oset)
{
#ifdef POSIX_SIGNALS
return sigprocmask(how, set, oset);
#else
# ifdef BSD_SIGNALS
switch(how) {
case SIG_BLOCK:
*oset = sigblock(*set);
break;
case SIG_UNBLOCK:
sigfillset(*oset);
*oset = sigsetmask(*oset);
sigsetmask(*oset & ~(*set));
break;
case SIG_SETMASK:
*oset = sigsetmask(*set);
break;
default:
adios(NULL, "unknown flag in SIGPROCMASK");
break;
}
return 0;
# endif
#endif
}
/*
* A version of the function `signal' that uses reliable
* signals, if the machine supports them. Also, (assuming
* OS support), it restarts interrupted system calls for all
* signals except SIGALRM.
*/
SIGNAL_HANDLER
SIGNAL (int sig, SIGNAL_HANDLER func)
{
#ifdef POSIX_SIGNALS
struct sigaction act, oact;
act.sa_handler = func;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
if (sig == SIGALRM) {
# ifdef SA_INTERRUPT
act.sa_flags |= SA_INTERRUPT; /* SunOS */
# endif
} else {
# ifdef SA_RESTART
act.sa_flags |= SA_RESTART; /* SVR4, BSD4.4 */
# endif
}
if (sigaction(sig, &act, &oact) < 0)
return (SIG_ERR);
return (oact.sa_handler);
#else
return signal (sig, func);
#endif
}
/*
* A version of the function `signal' that will set
* the handler of `sig' to `func' if the signal is
* not currently set to SIG_IGN. Also uses reliable
* signals if available.
*/
SIGNAL_HANDLER
SIGNAL2 (int sig, SIGNAL_HANDLER func)
{
#ifdef POSIX_SIGNALS
struct sigaction act, oact;
if (sigaction(sig, NULL, &oact) < 0)
return (SIG_ERR);
if (oact.sa_handler != SIG_IGN) {
act.sa_handler = func;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
if (sig == SIGALRM) {
# ifdef SA_INTERRUPT
act.sa_flags |= SA_INTERRUPT; /* SunOS */
# endif
} else {
# ifdef SA_RESTART
act.sa_flags |= SA_RESTART; /* SVR4, BSD4.4 */
# endif
}
if (sigaction(sig, &act, &oact) < 0)
return (SIG_ERR);
}
return (oact.sa_handler);
#else
SIGNAL_HANDLER ofunc;
if ((ofunc = signal (sig, SIG_IGN)) != SIG_IGN)
signal (sig, func);
return ofunc;
#endif
}
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