
VALID_OVERRIDE(4)DEVICES AND NETWORK INTERFACES VALID_OVERRIDE(4)

NAME
     valid_override - controls the use of efun::

SYNOPSIS
     int valid_override(string file, string efun_name);

DESCRIPTION
     Add valid_override to master.c in order to control  the  use
     of  the  efun::  prefix.   The  valid_override  function  in
     master.c will be called each time  the  driver  attempts  to
     compile  a  function  call  that  begins  with  efun::.   If
     valid_override returns 0, then that compile will fail.  Thus
     valid_override  provides  a  way  to  modify the behavior of
     efuns that isn't circumventable via the  efun::  prefix  (by
     having a simul_efun of the same name as the efun to be modi-
     fied and having valid_override disallow that simul_efun from
     being overriden).

     If you wish to have the original 3.1.2 efun:: behavior, sim-
     ply add a line to master.c that looks like this:

        int valid_override(string file, string efun) { return 1; }

     Here is an example valid_override that is more restrictive:

       int
       valid_override(string file, string name)
       {
           if (file == "/adm/obj/simul_efun") {
               return 1;
           }
           if (name == "destruct")
               return 0;
           if (name == "shutdown")
               return 0;
           if (name == "snoop")
               return 0;
           if (name == "exec")
               return 0;
           return 1;
        }

AUTHOR
     Truilkan@Basis

SEE ALSO
     valid_object(4)

Sun Release 4.1           Last change:                          1

