Section (2) getresuid
getresuid, getresgid — get real, effective and saved user/group IDs
#define _GNU_SOURCE /* See feature_test_macros(7) */ #include <unistd.h>
getresuid() returns the real
UID, the effective UID, and the saved set-user-ID of the
calling process, in the arguments
getresgid() performs the
analogous task for the process_zsingle_quotesz_s group IDs.
On success, zero is returned. On error, −1 is
errno is set
One of the arguments specified an address outside the calling program_zsingle_quotesz_s address space.
These system calls appeared on Linux starting with kernel 2.1.44.
The prototypes are given by glibc since version 2.3.2,
The original Linux
getresgid() system calls supported only
16-bit user and group IDs. Subsequently, Linux 2.4 added
getresgid32(), supporting 32-bit IDs. The
getresgid() wrapper functions
transparently deal with the variations across kernel
This page is part of release 4.16 of the Linux
man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
Copyright (C) 1997 Andries Brouwer (aebcwi.nl)
and Copyright (c) 2007, Michael Kerrisk <mtk.manpagesgmail.com>
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date. The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein. The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Modified, 2003-05-26, Michael Kerrisk, <mtk.manpagesgmail.com>