GETRESUID
Section: Linux Programmer's Manual (2)
Updated: 2017-09-15
Page Index
NAME
getresuid, getresgid - get real, effective and saved user/group IDs
SYNOPSIS
#define _GNU_SOURCE /* See
feature_test_macros(7) */
#include <unistd.h>
int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
DESCRIPTION
getresuid()
returns the real UID, the effective UID, and the saved set-user-ID
of the calling process, in the arguments
ruid,
euid,
and
suid,
respectively.
getresgid()
performs the analogous task for the process's group IDs.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.
ERRORS
- EFAULT
-
One of the arguments specified an address outside the calling program's
address space.
VERSIONS
These system calls appeared on Linux starting with kernel 2.1.44.
The prototypes are given by glibc since version 2.3.2,
provided
_GNU_SOURCE
is defined.
CONFORMING TO
These calls are nonstandard;
they also appear on HP-UX and some of the BSDs.
NOTES
The original Linux
getresuid()
and
getresgid()
system calls supported only 16-bit user and group IDs.
Subsequently, Linux 2.4 added
getresuid32()
and
getresgid32(),
supporting 32-bit IDs.
The glibc
getresuid()
and
getresgid()
wrapper functions transparently deal with the variations across kernel versions.
SEE ALSO
getuid(2),
setresuid(2),
setreuid(2),
setuid(2),
credentials(7)
COLOPHON
This page is part of release 5.10 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
https://www.kernel.org/doc/man-pages/.