Removing leading whitespace from a file?

[Anonymous Monk]

Hello fellow monks!

This is a simple question but since I am new here, I felt inclined to ask ( after 5 attempts ). How do I remove leading whitespace from every line in a file then 're-write' the 'new' version back? My 5th attempt is here:

#!/usr/bin/perl -w
use strict;
use fatal;

open( FH, "<test.txt" );
open( FH2, ">test.txt" );

while ( <FH> )
{
  s/^(\s+)//g;
  print FH2 $_;
}

close FH;
close FH2;

Warning: This sample does not work.
Thank you,
Alicia