osf1 man page for setsid

setsid(2)							System Calls Manual							 setsid(2)

NAME
       setsid - Sets the process group ID

SYNOPSIS
       #include <unistd.h>

       pid_t setsid( void );

       Application  developers	may  want  to  specify an #include statement for <sys/types.h> before the one for <unistd.h> if programs are being
       developed for multiple platforms. The additional #include statement is not required on Tru64 UNIX systems or by ISO  or	X/Open	standards,
       but may be required on other vendors' systems that conform to these standards.

STANDARDS
       Interfaces documented on this reference page conform to industry standards as follows:

       setsid():  XPG4, XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION
       The  setsid()  function creates a new session when the calling process is not a process group leader.  The calling process then 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.

RETURN VALUES
       Upon successful completion, the setsid function returns the value of the new process group ID.  Otherwise, a value of (pid_t)-1 is returned
       and errno is set to indicate the error.

ERRORS
       The  setsid()  function	sets  errno to the specified values for the following conditions: The calling process is already the process group
       leader, or the process group ID of another process matches the process ID of the calling process.

RELATED INFORMATION
       Functions: getpid(2), getsid(2), setpgid(2)

       Standards: standards(5) delim off

																	 setsid(2)