use strict;

my($f1,$f2,%ids_in_f1,%ids_in_f2);
my($file,$count);

$f1 = "f1_name.txt";
$f2 = "f2_name.txt";

open(F1,$f1);
while(<F1>)
  {
    my(@col);
    chop;
    next if(/\+/);
    next if(!$_);
    @col = split(/\s,\s/);
    $ids_in_f1{$col[0]} = 1;
  }
close(F1);
open(F2,$f2);
while(<F2>)
  {
    my(@col);
    chop;
    next if(/\+/);
    next if(!$_);
    # Split this file on tabs
    @col = split(/\t/);
    # This time the id is in the second column
    $ids_in_f2{$col[1]} = 1;
    if(!$ids_in_f1{$col[1]})
      {
        print "  Missing ID ".$col[1]."\n";
      }
  }
close(F2);

$count = 0;
print "\nThings in F1 not in F2\n";
foreach $file (sort keys(%ids_in_f1))
  {
    next if($ids_in_f2{$file});
    print "  $file\n";
    $count++;
  }
print "Total things in F1 not in F2 $count\n\n";