SETSID(2)                            SysV                            SETSID(2)



NAME
     setsid - set session and set process group ID

SYNOPSIS
     #include <sys/types.h>

     pid_t setsid(void);

DESCRIPTION
     The setsid function creates a new session when the calling process is not
     a process group leader.  Upon return, the calling process becomes the
     session leader of this session, becomes the process leader of the new
     process group, and has no controlling terminal.

     The process group ID of the calling process is set equal to its process
     ID.  The calling process becomes the only process in the new process
     group and the only process in the new session.

DIAGNOSTICS
     Upon successful completion, the value of the new process group ID is
     returned.  Otherwise, a value of -1 is returned and errno is set to
     indicate the error.

ERRORS
     setsid fails if:

     [EPERM]   The calling process is already the 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
     open(2), _exit(2), fork(2), kill(2), sigaction(2), getpid(2), exec(2),
     setpgid(2), </sys/types.h>