A note from Ian Bicking in http://mail.python.org/pipermail/stdlib-sig/2010-May/000948.html:

> I've had to do this sort of thing for similar reasons, like calling remote
> ssh commands, where a shell command is embedded in a positional argument.  I
> implemented my own thing, but the way pipes.quote works would have been
> nicer (the implementation could use a couple regexes instead of iterating
> over strings though).