*Works if properly implemented. Had to manually disable this behavior in eshell as it prevented you from running regex with two carets, e.g. '$ grep -E '^sometext[^ ]+moretext'.

You can also just run a sed style substitution in most shells, e.g. '$ !!:s/before/after/' or '$ !!:gs/x/y/', which is safer IMO.

You know... I've seen this notation on discussion forums (and probably IRC etc.) for years, and had no idea until now that it was a reference to this shell capability lol