1 /* Introduction to Non-Local Exits
2    Copyright (C) 1991-2022 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or
5    modify it under the terms of the GNU General Public License
6    as published by the Free Software Foundation; either version 2
7    of the License, or (at your option) any later version.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, see <https://www.gnu.org/licenses/>.
16 */
17 
18 #include <setjmp.h>
19 #include <stdlib.h>
20 #include <stdio.h>
21 
22 jmp_buf main_loop;
23 
24 void
abort_to_main_loop(int status)25 abort_to_main_loop (int status)
26 {
27   longjmp (main_loop, status);
28 }
29 
30 int
main(void)31 main (void)
32 {
33   while (1)
34     if (setjmp (main_loop))
35       puts ("Back at main loop....");
36     else
37       do_command ();
38 }
39 
40 
41 void
do_command(void)42 do_command (void)
43 {
44   char buffer[128];
45   if (fgets (buffer, 128, stdin) == NULL)
46     abort_to_main_loop (-1);
47   else
48     exit (EXIT_SUCCESS);
49 }
50