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 effective group ID
int setegid(gid_t gid);
is equal to the real group ID or the saved set-group-ID, or if the
process has appropriate privileges,
shall set the effective group ID of the calling process to
the real group ID, saved set-group-ID, and any supplementary group IDs
shall remain unchanged.
function shall not affect the supplementary group list in any way.
Upon successful completion, 0 shall be returned; otherwise, -1 shall
be returned and
set to indicate the error.
function shall fail if:
The value of the
argument is invalid and is not supported by the implementation.
The process does not have appropriate privileges and
does not match the real group ID or the saved set-group-ID.
The following sections are informative.
Refer to the RATIONALE section in
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