Originální popis anglicky:
setreuid, setregid - set real and/or effective user or group ID
Návod, kniha: Linux Programmer's Manual
#include <sys/types.h>
#include <unistd.h>
int setreuid(uid_t ruid, uid_t euid);
int setregid(gid_t rgid, gid_t egid);
setreuid sets real and effective user IDs of the current process.
Supplying a value of -1 for either the real or effective user ID forces the
system to leave that ID unchanged.
Unprivileged processes may only set the effective user ID to the real user ID,
the effective user ID or the saved effective user ID.
POSIX: It is unspecified whether unprivileged processes may set the real user ID
to the real user ID, the effective user ID or the saved effective user ID.
Linux: Unprivileged users may only set the real user ID to the real user ID or
the effective user ID.
Linux: If the real user ID is set or the effective user ID is set to a value not
equal to the previous real user ID, the saved user ID will be set to the new
effective user ID.
Completely analogously,
setregid sets real and effective group ID's of
the current process, and all of the above holds with "group" instead
of "user".
On success, zero is returned. On error, -1 is returned, and
errno is set
appropriately.
- EPERM
- The current process is not privileged (Linux: does not have
the CAP_SETUID capability in the case of setreuid(), or the
CAP_SETGID capability in the case of setregid()) and a
change other than (i) swapping the effective user (group) ID with the real
user (group) ID, or (ii) setting one to the value of the other or (iii)
setting the effective user (group) ID to the value of the saved user
(group) ID was specified.
Setting the effective user (group) ID to the saved user ID is possible since
Linux 1.1.37 (1.1.38).
BSD 4.3 (the
setreuid and
setregid function calls first appeared
in 4.2BSD).
getgid(2),
getuid(2),
seteuid(2),
setgid(2),
setresuid(2),
setuid(2),
capabilities(7)
