/* Introduction to Non-Local Exits

   Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This program 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

   of the License, or (at your option) any later version.

   This program 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 this program; if not, if not, see <http://www.gnu.org/licenses/>.

*/

#include <setjmp.h>

#include <stdlib.h>

#include <stdio.h>

jmp_buf main_loop;

void

abort_to_main_loop (int status)

{

  longjmp (main_loop, status);

}

int

main (void)

{

  while (1)

    if (setjmp (main_loop))

      puts ("Back at main loop....");

    else

      do_command ();

}

void

do_command (void)

{

  char buffer[128];

  if (fgets (buffer, 128, stdin) == NULL)

    abort_to_main_loop (-1);

  else

    exit (EXIT_SUCCESS);

}