SETRESUID(2)		   Linux Programmers Manual		 SETRESUID(2)



NAME
       setresuid, setresgid - set real, effective and saved user or group ID

SYNOPSIS
       #define _GNU_SOURCE
       #include 

       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 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 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 values
	      that are not permitted.

VERSIONS
       These calls are available under Linux since Linux 2.1.44.

CONFORMING TO
       These calls are non-standard; 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.

SEE ALSO
       getresuid(2),   getuid(2),   setfsgid(2),   setfsuid(2),   setreuid(2),
       setuid(2), capabilities(7), credentials(7), feature_test_macros(7)

COLOPHON
       This  page  is  part of release 3.05 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)