Tips to show similarities in files

Question

In a project, I found some css files that \"smell\" like there are copy-pasted rules in them.

I wonder what are your strategies for detecting copy-paste stuff in files.

Answer 1

There is a Copy-Paste Detection (CPD) project on sourceforge; http://pmd.sourceforge.net/cpd.html

But even in large projects I find my own knowledge of the code to be a reliable (although not foolproof) detection mechanism.

Also see this question for other suggestions.