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.
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/.