Build (or Rebuild) Info Dir

If you ever used Emacs info system you are well aware that C-h i brings you to the “dir” file, which contains a list of the Info file you can navigate to.

I am not sure why and how, but the dir file on my Emacs installation was not up-to-date and various info files were not listed.

Fortunately rebuilding the dir file is easy, since there is a specific utility install-info:

cd /usr/share/info
mv dir dir.orig
for file in *; do install-info --calign=36 --align=36 $file dir; done

… and voilà, the dir files contains all info files.

Note that the command above might require root access.