setreuid

SETREUID(2)		  Linux Programmer’s Manual		  SETREUID(2)



NAME
       setreuid, setregid - set real and/or effective user or group ID

SYNOPSIS
       #include <sys/types.h>
       #include <unistd.h>

       int setreuid(uid_t ruid, uid_t euid);
       int setregid(gid_t rgid, gid_t egid);

DESCRIPTION
       setreuid	 sets  real  and  effective  user IDs of the current process.
       Unprivileged users may only set the real user ID to the real  user  ID
       or  the	effective  user ID, and may only set the effective user ID to
       the real user ID, the effective user ID or the saved user ID.

       Supplying a value of -1 for either  the	real  or  effective  user  ID
       forces the system to leave that ID unchanged.

       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".


RETURN VALUE
       On  success, zero is returned.  On error, -1 is returned, and errno is
       set appropriately.

ERRORS
       EPERM  The current process is not the  super-user  and  changes	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.

NOTES
       Setting the effective user (group) ID to the saved user ID is possible
       since Linux 1.1.37 (1.1.38).

CONFORMING TO
       BSD  4.3	 (the  setreuid and setregid function calls first appeared in
       4.2BSD).

SEE ALSO
       getuid(2), getgid(2), setuid(2), setgid(2), seteuid(2), setresuid(2)



Linux 1.1.38			  1994-08-02			  SETREUID(2)