A program for identifying duplicated code

This paper describes a program called dup that finds occurrences of duplicated or related code in large software systems. The motivation is that duplication may be introduced into a large system as modifications are made to add new features or to fix bugs; rather than rewrite working sections of code, programmers may copy and modify sections of code. Over time, proliferation of copies can make the code more complex and more difficult to maintain. Dup searches such code for all pairs of duplicated sections. The user may choose to search either for identical sections of code, or for sections that match except for substitution of one set of variable names and constants for another a