After I modified my WordPress theme, I forgot which files I have made changes to. Going through each file would have wasted hours of time, not to mention the headache it would have caused. So I used a free program called FileCompare which allows you to compare the files inside two folders and show you which ones are different or which of the files are exactly the same. Using this program I compared the folders containing the modified WordPress theme and original theme files and it quickly showed me the few files I had made changes to. FileCompare uses binary compare instead of text compare, so it can work with all sorts of files including images and program files.
You can get FileCompare from the website of Steel Bytes software. The download is a portable application program packed inside a ZIP archive. You can extract it to a folder and run compare.exe from there.
The user interface of the FileCompare demands that you select two folders the files inside which you want to compare. The files of first folder are compared against the second folder. So if there are extra files in the second folder, it will not show you any information about this. But if there are extra files in the first folder, then it will show you message that certain file was not found in the second folder.
You can also choose whether you want to compare the files with hidden attributes or the symlinks. The files inside the first folder are compared recursively which means any files inside any sub-folders are also compared. You can start the comparison process by clicking on the Start button. In a short duration it will show you the files matched, files mismatched in size and files mismatched in data.
Conclusion: The FileCompare tool is a small useful tool to compare the files inside any two folders. It does not provide text mode comparison, neither does it show any details of data mismatches. But it can quickly show you which files are different in size or content.
You can download FileCompare from http://www.steelbytes.com/?mid=27.