SETRESUID(2) Linux Programmer's Manual SETRESUID(2)NAME
setresuid, setresgid - set real, effective and saved user or group ID
SYNOPSIS
#define _GNU_SOURCE
#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);
DESCRIPTIONsetresuid() sets the real user ID, the effective user ID, and the saved
set-user-ID of the current 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 parameters 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 current process (and always modifies the
file system GID to be the same as the effective GID), with the same
restrictions for non-privileged 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 NPROC rlimit.
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.
CONFORMING TO
These calls are non-standard; they also appear on HP-UX and some of the
BSDs.
HISTORY
This system call was first introduced in HP-UX. It is available under
Linux since Linux 2.1.44. These days it is also found in FreeBSD (for
emulation of Linux binaries).
NOTES
Under HP-UX and FreeBSD the prototype is found in <unistd.h>. Under
Linux the prototype is given by glibc since version 2.3.2 provided
_GNU_SOURCE is defined.
SEE ALSOgetresuid(2), getuid(2), setfsuid(2), setfsgid(2), setreuid(2),
setuid(2), capabilities(7)Linux 2.4 2003-05-26 SETRESUID(2)
