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)