Section: POSIX Programmer's Manual (3P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- get the process group ID of a session leader
pid_t getsid(pid_t pid);
function shall obtain the process group ID of the process that is the
session leader of the process specified by
)0, it specifies the calling process.
Upon successful completion,
shall return the process group ID of the session leader of the specified
process. Otherwise, it shall return -1 and set
to indicate the error.
function shall fail if:
The process specified by
is not in the same session as the calling process, and the
implementation does not allow access to the process group ID of the
session leader of that process from the calling process.
There is no process with a process ID equal to
The following sections are informative.
The Base Definitions volume of POSIX.1-2008,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see