#! perl -slw
use strict;
use Filter::Handle;

open FH1, '>', 'my.log' or die $!;
open FH2, '>', 'myother.log' or die $!;

tie *FH1, 'Filter::Handle', \*FH2, sub{ @_ }; ## << NOTE THE CHANGE!!!

print FH1 'Hello world!', $_ for 1 .. 10;