use File::Find;
use File::Basename;

# Read the contents of the first directory (DOC) into a hash
$first_dir = "c:/data/documents/pdfx/input";
%docs = ();
find (\&firstDir, $first_dir);
sub firstDir {
  /.doc/ or return;
  -f and ($name,$path,$suffix) = fileparse($File::Find::name);
  $docs{$name} = 1;
}

# Now read the contents of the second directory (PDF) into an array
$second_dir = "c:/data/documents/pdfx/output";
@pdfs=();
find (\&secondDir, $second_dir);
sub secondDir {
  /.pdf/ or return;
  -f and ($name,$path,$suffix) = fileparse($File::Find::name);
  push @pdfs, $name;
}

# Now delete the files in the second dir that aren't in the first dir.
foreach $file (@pdfs) {
  if (!defined($docs{$file})) {
    $delfiles = "${second_dir}/${file}";
    print "unlink $delfiles\n";
     unlink($delfiles);
  }
}