How can I tell if two files on the same filesystem are the same?
% cmp filepath1 filepath1 # compare identical files # no output: files are identical % cmp filepath1 filepath1 # compare different files filepath1 filepath1 differ: char 13274, line 221 If you want to see how they differ, use the file difference utility: diff: % diff filepath1 filepath1 # compare identical files # no output: files are identical % diff filepath1 filepath1 # compare different files …lots of output here… # files are different diff has lots of options that are worth investigating. Two useful ones are -cn to show n lines of the context on either side of each difference, and -un to show a unified difference with n lines of surrounding context. In both cases, n defaults to 3 if omitted. The output of diff can be applied to either of the files with the patch utility to recover the other. Consequently, it is common practice in Unix software development, particularly on mailing lists, to report file differences, which are generally small, rather than sending complete changed
