linux man page for getsid

GETSID(2)						     Linux Programmer's Manual							 GETSID(2)

NAME
       getsid - get session ID

SYNOPSIS
       #include <unistd.h>

       pid_t getsid(pid_t pid);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getsid():
	   Since glibc 2.12:
	       _POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
	   Before glibc 2.12:
	       _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

DESCRIPTION
       getsid(0)  returns the session ID of the calling process.  getsid(p) returns the session ID of the process with process ID p.  (The session
       ID of a process is the process group ID of the session leader.)

RETURN VALUE
       On success, a session ID is returned.  On error, (pid_t) -1 will be returned, and errno is set appropriately.

ERRORS
       EPERM  A process with process ID p exists, but it is not in the same session as the calling process, and the implementation considers  this
	      an error.

       ESRCH  No process with process ID p was found.

VERSIONS
       This system call is available on Linux since version 2.0.

CONFORMING TO
       SVr4, POSIX.1-2001.

NOTES
       Linux does not return EPERM.

SEE ALSO
       getpgid(2), setsid(2), credentials(7)

COLOPHON
       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2010-09-20								 GETSID(2)