+++ /dev/null
-.\" 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>
-.\"
-.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
-.\" This is free documentation; 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 2 of
-.\" the License, or (at your option) any later version.
-.\"
-.\" The GNU General Public License's references to "object code"
-.\" and "executables" are to be interpreted as the output of any
-.\" document formatting or typesetting system, including
-.\" intermediate and printed output.
-.\"
-.\" This manual 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 manual; if not, see
-.\" <http://www.gnu.org/licenses/>.
-.\" %%%LICENSE_END
-.\"
-.\" 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 2014-12-31 "Linux" "Linux Programmer's Manual"
-.SH NAME
-setsid \- creates a session and sets the process group ID
-.SH SYNOPSIS
-.ad l
-.B #include <unistd.h>
-.sp
-.B pid_t setsid(void);
-.br
-.ad b
-.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 it 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 it process ID).
-
-The calling process will be the only process in
-the new process group and in the new session.
-The new session has no controlling terminal.
-.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 CONFORMING TO
-SVr4, POSIX.1-2001.
-.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).
-
-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,
-.BR fork (2)
-and
-.BR _exit (2),
-and have the child do
-.BR setsid ().
-.SH SEE ALSO
-.BR setsid (1),
-.BR getsid (2),
-.BR setpgid (2),
-.BR setpgrp (2),
-.BR tcgetsid (3),
-.BR credentials (7)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
OSDN Git Service
