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/* Copyright (C) 1992, 1994, 1995 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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <sysdep.h>
#include <errno.h>
#include <stddef.h>
#include <signal.h>
/* If ACT is not NULL, change the action for SIG to *ACT.
If OACT is not NULL, put the old action for SIG in *OACT. */
int
DEFUN(__sigaction, (sig, act, oact),
int sig AND CONST struct sigaction *act AND struct sigaction *oact)
{
sighandler_t handler;
int save;
if (sig <= 0 || sig >= NSIG)
{
errno = EINVAL;
return -1;
}
if (act == NULL)
{
if (oact == NULL)
return 0;
/* Race condition, but this is the only way to do it. */
handler = signal (sig, SIG_IGN);
if (handler == SIG_ERR)
return -1;
save = errno;
(void) signal (sig, handler);
errno = save;
}
else
{
int i;
if (act->sa_flags != 0)
{
unimplemented:
errno = ENOSYS;
return -1;
}
for (i = 1; i < NSIG; ++i)
if (__sigismember (&act->sa_mask, i))
goto unimplemented;
handler = signal (sig, act->sa_handler);
if (handler == SIG_ERR)
return -1;
}
if (oact != NULL)
{
oact->sa_handler = handler;
__sigemptyset (&oact->sa_mask);
oact->sa_flags = 0;
}
return 0;
}
weak_alias (__sigaction, sigaction)
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