The output listed will be the files that are different in each folder, with files unique to folder1 aligning left, and files unique to folder 2 aligning right.
Note the indentation, which shows you which files are unique to each folder. In the above example, the file “photo 1 copy.PNG” and “photo 3.png” are aligned right, therefore they are unique to the OldPictures directory, and Folder-1-File.PNG and Folder-2-File copy.PNG are unique to the original Pictures folder.
This works great in Mac OS X, but it’s a generic unix command so you should find it usable in linux and other variants as well. If you do run into any compatibility issues, or find this command to be unnecessarily complex, try using diff to perform the same function.
If you want to see the difference between two folders on a Mac, launch the Terminal and read on, because we’ll show you how to compare two directories and the contents of those directories by using the Terminal to output a file containing the precise differences shown between two target folders.
This command will work in Mac OS X as well as most Unix based OS’s.