/*****************************************************************************
 *  Written by Chris Dunlap <cdunlap@llnl.gov>.
 *  Copyright (C) 2007-2016 Lawrence Livermore National Security, LLC.
 *  Copyright (C) 2002-2007 The Regents of the University of California.
 *  UCRL-CODE-155910.
 *
 *  This file is part of the MUNGE Uid 'N' Gid Emporium (MUNGE).
 *  For details, see <https://dun.github.io/munge/>.
 *
 *  MUNGE is free software: you can redistribute it and/or modify it under
 *  the terms of the GNU General Public License as published by the Free
 *  Software Foundation, either version 3 of the License, or (at your option)
 *  any later version.  Additionally for the MUNGE library (libmunge), 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 3 of the License, or (at your option) any later version.
 *
 *  MUNGE 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 General Public License
 *  and GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  and GNU Lesser General Public License along with MUNGE.  If not, see
 *  <http://www.gnu.org/licenses/>.
 *****************************************************************************
 *  Refer to "posignal.h" for documentation on public functions.
 *****************************************************************************/


#if HAVE_CONFIG_H
#  include "config.h"
#endif /* HAVE_CONFIG_H */

#include <errno.h>
#include <signal.h>
#include "posignal.h"


sigfun_t *
posignal (int signum, sigfun_t *f)
{
/*  A wrapper for the historical signal() function to do things the Posix way.
 *  cf. Stevens UNPv1 figure 5.6.
 */
    struct sigaction act0, act1;

    act1.sa_handler = f;
    sigemptyset (&act1.sa_mask);
    act1.sa_flags = 0;

#if 0
    if (signum == SIGALRM) {
#ifdef SA_INTERRUPT
        act1.sa_flags |= SA_INTERRUPT;  /* SunOS 4.x */
#endif /* SA_INTERRUPT */
    }
    else {
#ifdef SA_RESTART
        act1.sa_flags |= SA_RESTART;    /* SVR4, 4.4BSD */
#endif /* SA_RESTART */
    }
#endif /* 0 */

    if (sigaction (signum, &act1, &act0) < 0)
        return (SIG_ERR);
    return (act0.sa_handler);
}
