/*
 * ircsig.c: has a `my_signal()' that uses sigaction().
 *
 * written by matthew green, 1993.
 *
 * i stole bits of this from w. richard stevens' `advanced programming
 * in the unix environment' -mrg
 */


#include "irc.h"
#include "irc_std.h"

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 = {{ 0 }}, osa = {{ 0 }};

	if (sig_no < 0)
		return NULL;

	sa.sa_handler = 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 || SIGINT == 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);
}