glibc/sysdeps/posix/sysv_signal.c
1997-01-06 22:07:28 +00:00

59 lines
1.7 KiB
C

/* Copyright (C) 1991, 1992, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <signal.h>
/* Tolerate non-threads versions of Posix */
#ifndef SA_ONESHOT
#define SA_ONESHOT 0
#endif
#ifndef SA_NOMASK
#define SA_NOMASK 0
#endif
#ifndef SA_INTERRUPT
#define SA_INTERRUPT 0
#endif
/* Set the handler for the signal SIG to HANDLER,
returning the old handler, or SIG_ERR on error. */
__sighandler_t
__sysv_signal (sig, handler)
int sig;
__sighandler_t handler;
{
struct sigaction act, oact;
/* Check signal extents to protect __sigismember. */
if (handler == SIG_ERR || sig < 1 || sig >= NSIG)
{
__set_errno (EINVAL);
return SIG_ERR;
}
act.sa_handler = handler;
if (__sigemptyset (&act.sa_mask) < 0)
return SIG_ERR;
act.sa_flags = SA_ONESHOT | SA_NOMASK | SA_INTERRUPT;
act.sa_flags &= ~SA_RESTART;
if (__sigaction (sig, &act, &oact) < 0)
return SIG_ERR;
return oact.sa_handler;
}