NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON
SETEUID(2) Linux Programmer's Manual SETEUID(2)
seteuid, setegid - set effective user or group ID
#include <sys/types.h>
#include <unistd.h>
int seteuid(uid_t euid);
int setegid(gid_t egid);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
seteuid(), setegid(): _BSD_SOURCE || _POSIX_C_SOURCE >= 200112L ||
_XOPEN_SOURCE >= 600
seteuid() sets the effective user ID of the calling process. Unprivileged
user processes may only set the effective user ID to the real user ID, the
effective user ID or the saved set-user-ID.
Precisely the same holds for setegid() with "group" instead of "user".
On success, zero is returned. On error, -1 is returned, and errno is set
appropriately.
EPERM The calling process is not privileged (Linux: does not have the
CAP_SETUID capability in the case of seteuid(), or the CAP_SETGID
capability in the case of setegid()) and euid (respectively, egid) is
not the real user (group) ID, the effective user (group) ID, or the
saved set-user-ID (saved set-group-ID).
4.3BSD, POSIX.1-2001.
Setting the effective user (group) ID to the saved set-user-ID (saved set-
group-ID) is possible since Linux 1.1.37 (1.1.38). On an arbitrary system one
should check _POSIX_SAVED_IDS.
Under libc4, libc5 and glibc 2.0 seteuid(euid) is equivalent to setreuid(-1,
euid) and hence may change the saved set-user-ID. Under glibc 2.1 and later
it is equivalent to setresuid(-1, euid, -1) and hence does not change the
saved set-user-ID. Similar remarks hold for setegid().
geteuid(2), setresuid(2), setreuid(2), setuid(2), capabilities(7),
credentials(7)
This page is part of release 3.23 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/.
Linux 2007-07-26 SETEUID(2)