osf1 man page for getsid

getsid(2)							System Calls Manual							 getsid(2)

NAME
       getsid - Retrieves the session ID of a process

SYNOPSIS
       #include <unistd.h>

       pid_t getsid(
	       pid_t process_id );

       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:

       getsid():  XPG4-UNIX

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

PARAMETERS
       Specifies the process ID that identifies the process for which you want to retrieve a session ID.

DESCRIPTION
       Use the getsid function to retrieve the session ID for a process. The function returns the session ID assigned to the process identified in
       the process_id parameter.  If you specify 0 (zero) in the process_id parameter, the getsid function returns the session ID of  the  calling
       process.

RETURN VALUES
       Upon  successful completion, the getsid() function returns the session ID of the process identified by the process_id parameter. Otherwise,
       the function returns -1 and sets errno to indicate the error.

ERRORS
       The getsid() function sets errno to the specified values for the following conditions: The process_id parameter identifies a  process  that
       is in a different session from the calling process.  A process can use the getsid() function to get information only about processes in its
       own session.  The system cannot locate the process identified by the process_ID parameter.

SEE ALSO
       Functions:  exec(2), fork(2), getpid(2), setpgid(2), setsid(2)

       Standards:  standards(5)

																	 getsid(2)