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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHONThe Linux Programming Interface


SETSID(2)                     Linux Programmer's Manual                     SETSID(2)

NAME         top

       setsid - creates a session and sets the process group ID

SYNOPSIS         top

       #include <unistd.h>

       pid_t setsid(void);

DESCRIPTION         top

       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, the process
       group leader of the new process group, and has no controlling tty.  The
       process group ID and session ID of the calling process are set to the PID of
       the calling process.  The calling process will be the only process in this new
       process group and in this new session.

RETURN VALUE         top

       On success, the (new) session ID of the calling process is returned.  On
       error, (pid_t) -1 is returned, and errno is set to indicate the error.

ERRORS         top

       EPERM  The process group ID of any process equals the PID of the calling
              process.  Thus, in particular, setsid() fails if the calling process is
              already a process group leader.

CONFORMING TO         top

       SVr4, POSIX.1-2001.

NOTES         top

       A child created via fork(2) inherits its parent's session ID.  The session ID
       is preserved across an execve(2).

       A process group leader is a process with process group ID equal to its PID.
       In order to be sure that setsid() will succeed, fork(2) and _exit(2), and have
       the child do setsid().

SEE ALSO         top

       getsid(2), setpgid(2), setpgrp(2), tcgetsid(3), credentials(7)

COLOPHON         top

       This page is part of release 3.32 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can be found
       at http://www.kernel.org/doc/man-pages/.

Linux                                 2008-12-03                            SETSID(2)

HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface

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