NAME

     setsid — create session and set process group ID

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     pid_t
     setsid(void);

DESCRIPTION

     The setsid() system call 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.

RETURN VALUES

     Upon successful completion, the setsid() system call 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.  If
     an error occurs, setsid() returns -1 and the global variable errno is set to indicate the
     error.

ERRORS

     The setsid() system call will fail if:

     [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.

SEE ALSO

     setpgid(2), tcgetpgrp(3), tcsetpgrp(3)

STANDARDS

     The setsid() system call is expected to be compliant with the ISO/IEC 9945-1:1990
     (“POSIX.1”) specification.