Folder comparison program

I'm seeking a program that would compare the contents of two folders against each other.

Let me try to explain it this way... this is what I'm trying to do.

I have two folders, the folders hold music... on folder has 40 gigs of music and the other folder has 20 gigs of music. Some of the music that one folder has, is already present in another folder. I want these music combined in one folder. Some music are named differently, but still are the same music.

How could I accomplish that without manually going through them and checking them? That would take too long.

Is there such thing? It would be a total life savor.

Sorry, for those run on sentences that might've confused you guys.

If this is a computer you already have PHP installed on for doing that sort of stuff, you can write a small script that does the following.

Creates a "hash" folder.
Creates a "duplicates" folder.

Goes through the destination folder recursively, runs each file through md5_file(), and creates a new file in the "hash" directory named after the hash returned from md5_file.

Goes through the source directory recursively, running each file through md5_file just like before, except this time you'll be checking for the existence of a file named using the hash returned instead of creating the file.

Any time a hash exists for the file in the source folder, move that file to the "duplicates" folder.

Beyond Compare by Scooter Software.

I swear by it. The standard version is only $30 US and worth every penny. Not only compares folders, but files as well, and is a must have webmaster tool in my opinion.

Awesome! Thanks for that awesome reply ATNO! I am going to try Beyond Compare

I don't know...joebert's solution appeals to my [url]Tim Allen[/url] side. If the need arose, I think I'd probably have to go with both just for the coding experience.