I’m definitely not in favor of fossilizing Unix, but there’s a difference between avoiding fossilization and the kind of minimal, mathematical purity that we see GNU Grep trying to impose here. Unix has long since passed the point where it had that sort of minimalism in the standard commands. Modern Unix has all sorts of duplications and flourishes that aren’t strictly necessary, and for good reasons. One of them is that it’s nicer for the actual people using Unix. — We are stuck with egrep and fgrep (unless you like beating people)