SETRESUID(2) |
Linux Programmer's Manual |
SETRESUID(2) |
NAME
setresuid, setresgid - set real, effective and saved user or group ID
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
int setresuid(uid_t
ruid
, uid_t
euid
, uid_t
suid
);
int setresgid(gid_t
rgid
, gid_t
egid
, gid_t
sgid
);
DESCRIPTION
setresuid() sets the real user ID, the effective user ID, and the saved set-user-ID of the calling process.
Unprivileged user processes may change the real UID, effective UID, and saved set-user-ID, each to one of: the current real UID, the current effective UID or the current saved set-user-ID.
Privileged processes (on Linux, those having the
CAP_SETUID capability) may set the real UID, effective UID, and saved set-user-ID to arbitrary values.
If one of the arguments equals -1, the corresponding value is not changed.
Regardless of what changes are made to the real UID, effective UID, and saved set-user-ID, the file system UID is always set to the same value as the (possibly new) effective UID.
Completely analogously,
setresgid() sets the real GID, effective GID, and saved set-group-ID of the calling process (and always modifies the file system GID to be the same as the effective GID), with the same restrictions for unprivileged processes.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and
errno is set appropriately.
ERRORS
-
EAGAIN
-
uid does not match the current UID and this call would bring that user ID over its
RLIMIT_NPROC resource limit.
-
EPERM
-
The calling process is not privileged (did not have the
CAP_SETUID capability) and tried to change the IDs to values that are not permitted.
VERSIONS
These calls are available under Linux since Linux 2.1.44.
CONFORMING TO
These calls are nonstandard; they also appear on HP-UX and some of the BSDs.
NOTES
Under HP-UX and FreeBSD, the prototype is found in
<unistd.h>. Under Linux the prototype is provided by glibc since version 2.3.2.
The original Linux
setresuid() and
setresgid() system calls supported only 16-bit user and group IDs. Subsequently, Linux 2.4 added
setresuid32() and
setresgid32(), supporting 32-bit IDs. The glibc
setresuid() and
setresgid() wrapper functions transparently deal with the variations across kernel versions.
SEE ALSO
getresuid(2),
getuid(2),
setfsgid(2),
setfsuid(2),
setreuid(2),
setuid(2),
capabilities(7),
credentials(7)
COLOPHON
This page is part of release 3.53 of the Linux
man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.