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.
--- set the process group ID
If the calling process is not already a session leader,
sets the process group ID of the calling process to the process ID of
the calling process. If
creates a new session, then the new session has no controlling
function has no effect when the calling process is a session leader.
shall return the process group ID.
No errors are defined.
The following sections are informative.
It is unspecified whether this function behaves as
unless the process is already a session leader. Therefore, applications
are encouraged to use
function may be removed in a future version.
The Base Definitions volume of POSIX.1-2017,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
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
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