Good catch. I've changed arc.sh so that it should be POSIX sh compliant, but I'm unsure precisely what this requires and don't have the patience to devour the entire spec at the moment. I've tested it against bash and dash thus far. You can give it a look over at http://github.com/nex3/arc/blob/master/arc.sh if you want.

> Last point, eternal session is good, but if this means you keep your personal computer on for days, you're just killing the planet, and this obviously sucks.