This file is suspend.def, from which is created suspend.c.
It implements the builtin "suspend" in Bash.

Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash 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 2, or (at your option) any later
version.

Bash 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
for more details.

You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING.  If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.

$PRODUCES suspend.c

$BUILTIN suspend
$DEPENDS_ON JOB_CONTROL
$FUNCTION suspend_builtin
$SHORT_DOC suspend [-f]
Suspend the execution of this shell until it receives a SIGCONT
signal.  The `-f' if specified says not to complain about this
being a login shell if it is; just suspend anyway.
$END

#include <config.h>

#if defined (JOB_CONTROL)
#if defined (HAVE_UNISTD_H)
#  ifdef _MINIX
#    include <sys/types.h>
#  endif
#  include <unistd.h>
#endif

#include "../bashtypes.h"
#include <signal.h>
#include "../shell.h"
#include "../jobs.h"
#include "common.h"
#include "bashgetopt.h"

extern int job_control;

static SigHandler *old_cont;
#if 0
static SigHandler *old_stop;
#endif

/* Continue handler. */
sighandler
suspend_continue (sig)
     int sig;
{
  set_signal_handler (SIGCONT, old_cont);
#if 0
  set_signal_handler (SIGSTOP, old_stop);
#endif
  SIGRETURN (0);
}

/* Suspending the shell.  If -f is the arg, then do the suspend
   no matter what.  Otherwise, complain if a login shell. */
int
suspend_builtin (list)
     WORD_LIST *list;
{
  int opt, force;

  reset_internal_getopt ();
  force = 0;
  while ((opt = internal_getopt (list, "f")) != -1)
    switch (opt)
      {
      case 'f':
	force++;
	break;
      default:
	builtin_usage ();
	return (EX_USAGE);
      }
      
  list = loptend;

  if (job_control == 0)
    {
      builtin_error ("cannot suspend a shell without job control");
      return (EXECUTION_FAILURE);
    }

  if (force == 0)  
    {
      no_args (list);

      if (login_shell)
	{
	  builtin_error ("cannot suspend a login shell");
	  return (EXECUTION_FAILURE);
	}
    }

  old_cont = (SigHandler *)set_signal_handler (SIGCONT, suspend_continue);
#if 0
  old_stop = (SigHandler *)set_signal_handler (SIGSTOP, SIG_DFL);
#endif
  killpg (shell_pgrp, SIGSTOP);
  return (EXECUTION_SUCCESS);
}

#endif /* JOB_CONTROL */