busybox/miscutils/setsid.c
Denys Vlasenko a29b055bf1 setsid: check for setsid error directly
function                                             old     new   delta
setsid_main                                           74      66      -8

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-05-16 02:12:56 +02:00

50 lines
1.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* setsid.c -- execute a command in a new session
* Rick Sladkey <jrs@world.std.com>
* In the public domain.
*
* 1999-02-22 Arkadiusz Mickiewicz <misiek@pld.ORG.PL>
* - added Native Language Support
*
* 2001-01-18 John Fremlin <vii@penguinpowered.com>
* - fork in case we are process group leader
*
* 2004-11-12 Paul Fox
* - busyboxed
*/
#include "libbb.h"
int setsid_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int setsid_main(int argc UNUSED_PARAM, char **argv)
{
if (!argv[1])
bb_show_usage();
/* setsid() is allowed only when we are not a process group leader.
* Otherwise our PID serves as PGID of some existing process group
* and cannot be used as PGID of a new process group. */
if (setsid() < 0) {
pid_t pid = fork_or_rexec(argv);
if (pid != 0) {
/* parent */
/* TODO:
* we can waitpid(pid, &status, 0) and then even
* emulate exitcode, making the behavior consistent
* in both forked and non forked cases.
* However, the code is larger and upstream
* does not do such trick.
*/
exit(EXIT_SUCCESS);
}
/* child */
/* now there should be no error: */
setsid();
}
BB_EXECVP(argv[1], argv + 1);
bb_simple_perror_msg_and_die(argv[1]);
}