0
 1
  2
   3

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
open(FH, "<", "test.txt");
open(FH2, ">", "test2.txt" );
while(<FH>) {
  s/^(\s+)//g;
  print FH2 $_;
}
close FH2;
close FH;

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
open(FH, "<", "test.txt");
my @file = <FH>;
close(FH);
open(FH, ">", "test.txt" );
foreach (@file) {
  s/^(\s+)//g;
  print FH $_;
}
close FH;