What is it?

This is a command line Java app to find duplicate files on your computer.

But I hate Java

Well, there you go then.

Can't you write it in C/Go/Rust/Python/Erlang/something else?

Yes, probably, but I'm lazy.

How can I run it?

You can either build the application from source, or download a pre-compiled version.

Build from source

To build from source, you need Git, a Java JDK, and Maven:

git clone https://github.com/caluml/finddups
mvn assembly:single
java -jar target/finddups-0.0.1-SNAPSHOT-jar-with-dependencies.jar 1000000 /home /tmp

Precompiled

To just run the supplied version (might be a little out of date):
Download https://github.com/caluml/finddups/releases/download/v0.0.1/finddups-0.0.1.jar
java -jar finddups-0.0.1.jar 1000000 /home /tmp

How does it work?

• First, it recurses the given directory/ies, building a list of files.
• Then, it looks for files which have identically sized files.
• It then reads those identically sized files, comparing them byte for byte until it finds a byte that doesn't match, or it reaches the end of the file.
  The app outputs its errors to stderr, and its results to stdout as it goes.

Why not use MD5 or SHA or $HASHING_ALGORITHM

I chose not to use any kind of hashing or CRC system, as that would require reading the entire file, which would be less efficient if a byte near the beginning was different.

This sucks. How can I express my hate?

Any suggestions/comments to my github username at gmail.com

Caveats

I have only tested this on Linux, with Java 6, 7 and 8.