SETUID(2) | System Calls Manual | SETUID(2) |
setuid
, seteuid
,
setgid
, setegid
—
set user and group ID
#include
<unistd.h>
int
setuid
(uid_t
uid);
int
seteuid
(uid_t
euid);
int
setgid
(gid_t
gid);
int
setegid
(gid_t
egid);
The setuid
() function sets the real and
effective user IDs and the saved set-user-ID of the current process to the
specified value. The setuid
() function is permitted
if the effective user ID is that of the superuser, or if the specified user
ID is the same as the effective user ID. If not, but the specified user ID
is the same as the real user ID, setuid
() will set
the effective user ID to the real user ID.
The setgid
() function sets the real and
effective group IDs and the saved set-group-ID of the current process to the
specified value. The setgid
() function is permitted
if the effective user ID is that of the superuser, or if the specified group
ID is the same as the effective group ID. If not, but the specified group ID
is the same as the real group ID, setgid
() will set
the effective group ID to the real group ID. Supplementary group IDs remain
unchanged.
The seteuid
() function
(setegid
()) sets the effective user ID (group ID) of
the current process. The effective user ID may be set to the value of the
real user ID or the saved set-user-ID (see
intro(2) and
execve(2)); in this way, the effective
user ID of a set-user-ID executable may be toggled by switching to the real
user ID, then re-enabled by reverting to the set-user-ID value. Similarly,
the effective group ID may be set to the value of the real group ID or the
saved set-group-ID.
The setuid
(),
seteuid
(), setgid
(), and
setegid
() functions return the value 0 if
successful; otherwise the value -1 is returned and the global
variable errno is set to indicate the error.
setuid
() and
seteuid
() will succeed unless:
EPERM
]setgid
() and
setegid
() will succeed unless:
EPERM
]getgid(2), getuid(2), issetugid(2), setgroups(2), setregid(2), setresgid(2), setresuid(2), setreuid(2)
The setuid
(),
seteuid
(), setgid
(), and
setegid
() functions conform to IEEE
Std 1003.1-2008 (“POSIX.1”).
The setuid
() system call first appeared in
Version 1 AT&T UNIX;
setgid
() in Version 4
AT&T UNIX; and seteuid
() and
setegid
() in 4.2BSD.
September 9, 2014 | OpenBSD-current |