Emacs Lisp: Directory Path Should End in a Slash

By Xah Lee. Date:

In emacs lisp, dir path should end in a slash.

when your command query user for dir path, user may not add the ending slash. Your program can add it, like this:

(setq inputDir (file-name-as-directory inputDir) ) ; normalize dir path

calling file-name-as-directory is better than writing code to check and append slash yourself.

Directory Names (ELISP Manual)