anchor.diff:  %%           fetching all addresses for the user and then examining
   %%           them to see if any of them is a tel: URL, or has a
   %%           user part which is all numeric or is an E.164 number.
  +%%           The numbering plan in the number return is not specified.
   %% Returns : Number  |
   %%           nomatch |
   %%           error
  
positive.code: 	]).
  
  %%--------------------------------------------------------------------
  %% Internal exports - gen_server callbacks
  %%--------------------------------------------------------------------
  -export([
  	 init/1, 
  	 handle_call/3, 
  	 handle_cast/2, 
  	 handle_info/2, 
  	 terminate/2, 
  	 code_change/3
  	]).
  
  %%--------------------------------------------------------------------
  %% Extra exports - module specific manual-use functions
  -export([
  	 reload_userdb/0
  	 ]).
  
  %%--------------------------------------------------------------------
  %% Include files
  %%--------------------------------------------------------------------
  -include("siprecords.hrl").
  %% needed for file:read_file_info
  -include_lib("kernel/include/file.hrl").
  
  
  %%--------------------------------------------------------------------
  %% Records
  %%--------------------------------------------------------------------
  -record(user, {
  	  name,
  	  password,
  	  classes,
  	  forward
  	 }).
  -record(address, {
  	  user,
  	  address
  	 }).
  
  -record(state, {
  	  fn,
  	  file_mtime,
  	  last_fail,
  	  userlist,
  	  addresslist
  	 }).
  
  %%--------------------------------------------------------------------
  %% Macros
  %%--------------------------------------------------------------------
  %% how often we will log errors with our periodical reading of the
  %% user database file
  -define(LOG_THROTTLE_SECONDS, 300).
  
  %%====================================================================
  %% External functions
  
negative.code: %%           Spec = OTP supervisor child specification
  %%--------------------------------------------------------------------
  yxa_init() ->
      [{sipuserdb_file_backend, {sipuserdb_file_backend, start_link, []},
        permanent, 2000, worker, [sipuserdb_file_backend]}
      ].
  
  %%--------------------------------------------------------------------
  %% Function: get_user_with_address(Address)
  