|  | /* This testcase is part of GDB, the GNU debugger. | 
|  |  | 
|  | Copyright 2012-2023 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 3 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, see <http://www.gnu.org/licenses/>.  */ | 
|  | #include <stdio.h> | 
|  | #include <stdlib.h> | 
|  | #include <signal.h> | 
|  | #include <sys/wait.h> | 
|  | #include <unistd.h> | 
|  |  | 
|  | void | 
|  | do_nothing (void) | 
|  | { | 
|  | } | 
|  |  | 
|  | void | 
|  | handle (int sig) | 
|  | { | 
|  | do_nothing (); /* handle marker */ | 
|  | } | 
|  |  | 
|  | int | 
|  | main () | 
|  | { | 
|  | int i; | 
|  | signal (SIGHUP, handle); | 
|  |  | 
|  | raise (SIGHUP);		/* first HUP */ | 
|  |  | 
|  | signal (SIGCHLD, handle); | 
|  | for (i = 0; i < 3; i++)	/* fork loop */ | 
|  | { | 
|  | switch (fork()) | 
|  | { | 
|  | case -1: | 
|  | perror ("fork"); | 
|  | exit (1); | 
|  | case 0: | 
|  | exit (0); | 
|  | } | 
|  | wait (NULL); | 
|  | } | 
|  |  | 
|  | raise (SIGHUP);		/* second HUP */ | 
|  |  | 
|  | raise (SIGHUP);		/* third HUP */ | 
|  | } | 
|  |  |