In debian/ubuntu I want to a) create a list of all the files in one directory tree b) do the same for a second directory tree c) compare the two lists such that, only the file NAMES are compared (i.e. just comparing the "file.txt" part so that "/home/folder/file.txt" == "/home/secondfolder/folder/file.txt) d) output a list of all the duplicates can anyone please explain how to do this using scripting languages or regex or something?