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.
If gid is equal to the real group ID or the saved set-group-ID, or if
the process has appropriate privileges, setegid() shall set the
effective group ID of the calling process to gid; the real group ID,
saved set-group-ID, and any supplementary group IDs shall remain
The setegid() function shall not affect the supplementary group list
in any way.
The setegid() function shall fail if:
EINVAL The value of the gid argument is invalid and is not supported
by the implementation.
EPERM The process does not have appropriate privileges and gid does
not match the real group ID or the saved set-group-ID.
The following sections are informative.
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 http://www.unix.org/online.html .
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
IEEE/The Open Group 2013 SETEGID(3P)