NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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 terminal.  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

       setsid(1), getsid(2), setpgid(2), setpgrp(2), tcgetsid(3),
       credentials(7)

COLOPHON         top

       This page is part of release 3.71 of the Linux 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/.

Linux                            2013-02-11                        SETSID(2)