/* Copyright (C) 1991, 1992, 1996, 1997, 2005 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 Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #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 (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; __sigemptyset (&act.sa_mask); act.sa_flags = (SA_ONESHOT | SA_NOMASK | SA_INTERRUPT) & ~SA_RESTART; /* In Linux (as of 2.6.25), fails only if sig is SIGKILL or SIGSTOP */ if (sigaction (sig, &act, &oact) < 0) return SIG_ERR; return oact.sa_handler; } strong_alias(__sysv_signal,sysv_signal)