NAME
setresuid, setresgid - set real, effective and saved user or group ID SYNOPSIS
#define GNUSOURCE /* See featuretestmacros(7) */
#include
int setresuid(uidt ruid, uidt euid, uidt suid); int setresgid(gidt rgid, gidt egid, gidt 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 CAPSETUID 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 RLIMITNPROC resource limit. EPERM The calling process is not privileged (did not have the CAPSETUID 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
. 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 setre‐
suid32() and setresgid32(), supporting 32-bit IDs. The glibc setre‐ suid() 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/.
Linux 2010-11-22 SETRESUID(2)