#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.

SEE ALSO

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

STANDARDS

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

BSD                              June 4, 1993                              BSD