How to find total MB of a directory plus all subdirectories

[Bruno Wolff III]

On Thu, Mar 08, 2007 at 22:01:24 +0100,
  Nigel Henry <cave.dnb at tiscali.fr> wrote:
> 
> Thanks Todd, and you Bruno. Now I've learned a bit about using quotes, but why 
> does that apply to the directory you are accessing using du, but doesn't 
> apply to the subdirectories within that directory?

It is a feature of the command line. Internally the names don't need
to be quoted. (Though some commands will run other commands using a shell
and shell expansion and quoting will apply to those commands.)

If you want to read more about shell commands, try man bash. (There are
other shells, but bash is the normal default.)