blob: c573fae343fa63bc350ebc726e72ab95b792f42b [file] [log] [blame]
Bernhard Reutner-Fischerc89982d2006-06-03 19:49:21 +00001/* vi: set sw=4 ts=4: */
Paul Fox42403642005-08-01 22:52:09 +00002/*
3 * setsid.c -- execute a command in a new session
4 * Rick Sladkey <jrs@world.std.com>
5 * In the public domain.
6 *
Denis Vlasenkob44c7902008-03-17 09:29:43 +00007 * 1999-02-22 Arkadiusz Mickiewicz <misiek@pld.ORG.PL>
Paul Fox42403642005-08-01 22:52:09 +00008 * - added Native Language Support
9 *
10 * 2001-01-18 John Fremlin <vii@penguinpowered.com>
11 * - fork in case we are process group leader
12 *
13 * 2004-11-12 Paul Fox
14 * - busyboxed
15 */
16
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000017#include "libbb.h"
Paul Fox42403642005-08-01 22:52:09 +000018
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +000019int setsid_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +000020int setsid_main(int argc UNUSED_PARAM, char **argv)
Mike Frysingere1d41b32006-03-23 02:07:41 +000021{
Denis Vlasenkob44c7902008-03-17 09:29:43 +000022 if (!argv[1])
Paul Fox42403642005-08-01 22:52:09 +000023 bb_show_usage();
Paul Fox42403642005-08-01 22:52:09 +000024
Denis Vlasenkob44c7902008-03-17 09:29:43 +000025 /* setsid() is allowed only when we are not a process group leader.
26 * Otherwise our PID serves as PGID of some existing process group
27 * and cannot be used as PGID of a new process group. */
Denys Vlasenkoa29b0552010-05-16 02:12:56 +020028 if (setsid() < 0) {
29 pid_t pid = fork_or_rexec(argv);
30 if (pid != 0) {
31 /* parent */
32 /* TODO:
33 * we can waitpid(pid, &status, 0) and then even
34 * emulate exitcode, making the behavior consistent
35 * in both forked and non forked cases.
36 * However, the code is larger and upstream
37 * does not do such trick.
38 */
39 exit(EXIT_SUCCESS);
40 }
Paul Fox42403642005-08-01 22:52:09 +000041
Denys Vlasenkoa29b0552010-05-16 02:12:56 +020042 /* child */
43 /* now there should be no error: */
44 setsid();
45 }
Paul Fox42403642005-08-01 22:52:09 +000046
Denys Vlasenko41ddd9f2010-06-25 01:46:53 +020047 argv++;
Pascal Bellard21e8e8d2010-07-04 00:57:03 +020048 BB_EXECVP_or_die(argv);
Paul Fox42403642005-08-01 22:52:09 +000049}