Rewriting the GNU Coreutils in Rust

Because a system administrator may spend lots of time iterating between executing command lines, writing those command lines into a shell script, and debugging said command lines.

Predictability is vitally important, especially if it's 3am and I'm trying to figure out why this shell script that had been working suddenly breaks in the script but works fine when executed by hand.

There's a reason code deltas for interactive operation were few and far between, and mostly invisible (eg, stripping color). When the utility didn't handle it, "standard" shell aliases (eg, "rm -i") could do the trick. Plenty of utilities in the last decade seem to think that I *always* want a huge, complex TUI for getting data, or think it knows better about how I want my output presented.

I have high confidence that grep in an interactive shell and grep in a shell script will do essentially the same thing (except for things that apply to all scripting, like proper handling of globs). I have little confidence a "modern" grep replacement won't have some weird hacky behavior that was put in because it looks cool and will cost me an hour of hair-pulling early in the am trying to track it down.