/* This testcase is part of GDB, the GNU debugger. Copyright 2017 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 . */ #include #include #include static void daemon_main (void) { } int main () { pid_t child; alarm (60); /* Normally we're a progress group leader at this point, so can't create a session. Fork so the child can create a new session. */ child = fork (); if (child == -1) return 1; else if (child != 0) return 0; else { /* In child. Switch to a new session. */ pid_t session = setsid (); if (session == -1) return 1; /* Fork again, so that the grand child (what we want to debug) can't accidentally acquire a controlling terminal, because it's not a session leader. We're not opening any file here, but this is representative of what daemons do. */ child = fork (); if (child == -1) return 1; else if (child != 0) return 0; /* In grandchild. */ daemon_main (); while (1) sleep (1); } return 0; }