I think if we make too much of a habit of this, we'll wind up with painful collisions. It also does the wrong thing with no feedback if you try to set a shell

I think if we make too much of a habit of this, we'll wind up with painful collisions. It also does the wrong thing with no feedback if you try to set a shell variable that isn't actually recognized (and possibly if you misspell the option name, &c). That said, I agree that it can work quite nicely in the small, but it should probably be reserved for things like VERBOSE where you are likely to want propagation. > Env vars provide a key/value interface, which is trickier to handle with arguments Many (most? all?) languages practical for assembling a shell utility have a getopt-ish library that should make this easier (though still likely not as easy as grabbing from a shell var, granted).