SETSID(2)                   BSD System Calls Manual                  SETSID(2)

NAME
     setsid -- create session and set process group ID

SYNOPSIS
     #include <unistd.h>

     pid_t
     setsid(void);

DESCRIPTION
     The setsid function creates a new session.  The calling process is the
     session leader of the new session, is the process group leader of a new
     process group and has no controlling terminal.  The calling process is
     the only process in either the session or the process group.

     Upon successful completion, the setsid function returns the value of the
     process group ID of the new process group, which is the same as the
     process ID of the calling process.

ERRORS
     If an error occurs, setsid returns -1 and the global variable errno is
     set to indicate the error, as follows:

     [EPERM]            The calling process is already a process group leader,
                        or the process group ID of a process other than the
                        calling process matches the process ID of the calling
                        process.

LEGACY SYNOPSIS
     #include <sys/types.h>
     #include <unistd.h>

     The include file <sys/types.h> is necessary.

SEE ALSO
     setpgid(3), tcgetpgrp(3), tcsetpgrp(3), compat(5)

STANDARDS
     The setsid function is expected to be compliant with the IEEE Std
     1003.1-1988 (``POSIX.1'') specification.

BSD                              June 4, 1993                              BSD