When I use application manager to uninstall a software, I found that the storage is not fully reclaimed. How can I completely uninstall a software? Thanks. I apologize if this has been asked before, but I can't find an answer.

open up terminal, and type in ls -a ("ls" lists files in current directory, -a shows all files), then "rm -r" (remove recursively) the folders belonging to programs you don't want to use anymore.

The folders starting with periods are hidden folders which programs leave behinds to store user data (preferences and such), and can be safely deleted.

example

Thanks for the reply. However, sometimes I don't know which directory should I check. For example, the application may put sth in /usr/lib and /usr/bin, or /opt. It may also just put a libxxx in /usr/lib.

Ideally, when uninstalling a program, any unused libs will be removed with it. The only thing that should stay are folders left in your user directory. Anything outside of your user folder should be handled by your package manager (try apt-get autoremove?)

Thank you very much. Will try it again.