I see a couple of things here. First of all, not sure if this is a typo, but the way you're creating the hashes isn't right. The normal way to assign to a hash is

my %hash = ( key1 => value1, key2 => value2 );
...
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The other thing is that if your real data is like what you have here, you'll never get a match because the keys in %sdirdigest will never have exactly the same value as any key in %ddirrdigest because the root paths are different. Update: more precisely, the keys that go into both of your hashes are absolute paths. What you really want are the relative paths to the files, based on the respective starting directories. The way to fix this is to use $File::Find::dir instead of getcwd in your subs. Also it looks like you're trying to copy a file onto itself. Is that what you meant?

no, I posted my code in the readmore tags, in my original post. What happened is that initially I was only doing this in the dir that was specified at the command line, but later decided to add the ability to recurse dirs. my original code concatenated the dir onto the $key so that it copied appropriately, but when I added recursion, I could not longer copy the files in the same way, problem is I have no idea how best to proceed.

Take a look at the rest of my code? Thanks.

update: apologies, if that came off inappropriately, I was really just meaning to ask to have another look. Thanks for the pointer, I will take a look at File::Find:dir. One question, though. Does the logic make sense to get the filename for the second dir? I am probably just missing something obvious. I appreciate the help. Thanks again.

Ok. I posted an update above - basically you can use $File::Find::dir instead of getcwd so that the relative path instead of the absolute path becomes the key. But now I'm unclear - I understand that if two files in corresponding relative paths have matching MD5 sums you want to do something, but I don't understand what that is. Right now what would happen is that you copy the file onto itself.

If this is the task, it will go easier if the MD5 signatures are the keys of the hash and the filenames are the file paths. that way, when you come upon a new file, simply calculate its MD5 signature, and see if that signature already exists as a hash key.

Here is some code to illustrate that:

my %file_sig;
find( \&find_dup, $root_dir);

sub find_dup
{
   my $name = $_;
   my $full_name = $File::Find::name;
   my $dir = $File::Find::dir;

   if (-f $name) {
      open IN, "<$full_name";
      my $digest = Digest::MD5->new->addfile(*IN)->hexdigest;
      close IN;
      if (exists $file_sig{ $digest }) {
         print "$full_name is a duplicate of $file_sig{ $digest }\n";
      }
      else {
         $file_sig{ $digest } = $full_name;
      }
   }
}
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No, not exactly, I am synchronizing 2 dirs. I updated my post with the rest of the code in readmore tags...

Take a look at rsync, which does what it seems you are trying to do. I don't know how well it works on Windows, though I expect it should work fine in Cygwin.

You're comparing files from different disks. So, you simply have that:

"c:/temp/filename.txt" eq "e:/temp/filename.txt"
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"/temp/filename.txt" eq "/temp/filename.txt"
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