diff options
Diffstat (limited to 'man2/setsid.2')
| -rw-r--r-- | man2/setsid.2 | 100 |
1 files changed, 0 insertions, 100 deletions
diff --git a/man2/setsid.2 b/man2/setsid.2 deleted file mode 100644 index fe86939e2..000000000 --- a/man2/setsid.2 +++ /dev/null @@ -1,100 +0,0 @@ -.\" Copyright Michael Haardt (michael@cantor.informatik.rwth-aachen.de) -.\" Sat Aug 27 20:43:50 MET DST 1994 -.\" and Copyright (C) 2014, Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: GPL-2.0-or-later -.\" -.\" Modified Sun Sep 11 19:19:05 1994 <faith@cs.unc.edu> -.\" Modified Mon Mar 25 10:19:00 1996 <aeb@cwi.nl> (merged a few -.\" tiny changes from a man page by Charles Livingston). -.\" Modified Sun Jul 21 14:45:46 1996 <aeb@cwi.nl> -.\" -.TH setsid 2 (date) "Linux man-pages (unreleased)" -.SH NAME -setsid \- creates a session and sets the process group ID -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <unistd.h> -.PP -.B pid_t setsid(void); -.fi -.SH DESCRIPTION -.BR setsid () -creates a new session if the calling process is not a -process group leader. -The calling process is the leader of the new session -(i.e., its session ID is made the same as its process ID). -The calling process also becomes -the process group leader of a new process group in the session -(i.e., its process group ID is made the same as its process ID). -.PP -The calling process will be the only process in -the new process group and in the new session. -.PP -Initially, the new session has no controlling terminal. -For details of how a session acquires a controlling terminal, see -.BR credentials (7). -.SH RETURN VALUE -On success, the (new) session ID of the calling process is returned. -On error, -.I "(pid_t)\ \-1" -is returned, and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EPERM -The process group ID of any process equals the PID of the calling process. -Thus, in particular, -.BR setsid () -fails if the calling process is already a process group leader. -.SH STANDARDS -POSIX.1-2008. -.SH HISTORY -POSIX.1-2001, SVr4. -.SH NOTES -A child created via -.BR fork (2) -inherits its parent's session ID. -The session ID is preserved across an -.BR execve (2). -.PP -A process group leader is a process whose process group ID equals its PID. -Disallowing a process group leader from calling -.BR setsid () -prevents the possibility that a process group leader places itself -in a new session while other processes in the process group remain -in the original session; -such a scenario would break the strict -two-level hierarchy of sessions and process groups. -In order to be sure that -.BR setsid () -will succeed, call -.BR fork (2) -and have the parent -.BR _exit (2), -while the child (which by definition can't be a process group leader) calls -.BR setsid (). -.PP -If a session has a controlling terminal, and the -.B CLOCAL -flag for that terminal is not set, -and a terminal hangup occurs, then the session leader is sent a -.B SIGHUP -signal. -.PP -If a process that is a session leader terminates, then a -.B SIGHUP -signal is sent to each process in the foreground -process group of the controlling terminal. -.SH SEE ALSO -.BR setsid (1), -.BR getsid (2), -.BR setpgid (2), -.BR setpgrp (2), -.BR tcgetsid (3), -.BR credentials (7), -.BR sched (7) |