/*
 * ircsig.c: has a `my_signal()' that uses sigaction().
 *
 * Copyright (c) 1993-2016 Matthew R. Green.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * written by matthew green, 1993.
 *
 * i stole bits of this from w. richard stevens' `advanced programming
 * in the unix environment' -mrg
 */

#include "irc.h"
IRCII_RCSID("@(#)$eterna: ircsig.c,v 1.20 2016/12/04 21:40:49 gkm Exp $");

sigfunc *
my_signal(int sig_no, sigfunc *sig_handler, int misc_flags)
{
	/*
	 * misc_flags is unused currently.  it's planned to be used
	 * to use some of the doovier bits of sigaction(), if at
	 * some point we need them, -mrg
	 */

	struct sigaction sa, osa;

	/*
	 * have to (void *) this because of strict type checking
	 * on some systems -glen
	 */
	sa.sa_handler = (void (*)(int)) sig_handler;

	sigemptyset(&sa.sa_mask);
	sigaddset(&sa.sa_mask, sig_no);

	/* this is ugly, but the `correct' way.  i hate c. -mrg */
	sa.sa_flags = 0;
#if defined(SA_RESTART) || defined(SA_INTERRUPT)
	if (SIGALRM == sig_no)
	{
# if defined(SA_INTERRUPT)
		sa.sa_flags |= SA_INTERRUPT;
# endif /* SA_INTERRUPT */
	}
	else
	{
# if defined(SA_RESTART)
		sa.sa_flags |= SA_RESTART;
# endif /* SA_RESTART */
	}
#endif /* SA_RESTART || SA_INTERRUPT */

	if (0 > sigaction(sig_no, &sa, &osa))
		return ((sigfunc *)SIG_ERR);

	return ((sigfunc *)osa.sa_handler);
}
