'cd ". "' is valid; it means "set the current directory to the one named [dot][space]". I assumed it was something he'd seen as a way to sortof-conceal a direc

'cd ". "' is valid; it means "set the current directory to the one named [dot][space]". I assumed it was something he'd seen as a way to sortof-conceal a directory, since it's both hidden and looks a lot like the [dot] directory that you'd expect to find everywhere.