[dalke]

> What if the `$app` contains spaces?

The author writes "Whether dealing with string literals or back-ticks for expressing a command line, you can refer to a variable foo as $foo and it will be escaped properly."

http://docs.julialang.org/en/release-0.4/manual/running-exte... confirms that `` has special escaping rules designed to prevent the problems you pointed out.

> Or hyphens?

The interpretation of hyphens depends on the program being called, not the shell. There is no automated way to escape them.

I agree with everything else you wrote.

[viraptor]

Ok, I'm impressed. That's actually a pretty cool solution that's missing in every other backtick-enabled language I know.