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);

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 CAP_SETUID 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 RLIMIT_NPROC resource limit.

       EPERM  The calling process is not privileged (did not have the CAP_SETUID capability) and tried to change the IDs to val-
              ues 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 <unistd.h>.  Under Linux the prototype is provided by glibc since ver-
       sion 2.3.2.

SEE ALSO
       getresuid(2),  getuid(2),  setfsgid(2),  setfsuid(2),  setreuid(2),  setuid(2),  capabilities(7),  credentials(7),   fea-
       ture_test_macros(7)

COLOPHON
       This  page  is  part of release 3.25 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                                               SETRESUID(2)