use strict;
use warnings;
my $passwdfile = "d.txt";
my %seen = ();
{
   local @ARGV = ($passwdfile);
   local $^I = '.bac'; 
   while(<>){
   	  $_ =~ s/^\s+//;
      $seen{$_}++;
      next if $seen{$_} > 1;
      print;
   }
}
print "finished";