Generating all xdg-mime commands

This generates the xdg-mime commands for each .desktop files and the mimetypes they contain:

find /usr/share/applications ~/.local/share/applications \
  -iname '*.desktop' -print0 | while IFS= read -r -d $'\0' d; do
    for m in $(grep MimeType "$d" | cut -d= -f2 | tr ";" " "); do
        echo xdg-mime default "'$d'" "'$m'"
    done
done

Suggested on https://unix.stackexchange.com/a/361705