FWIW this is one reason I designed the Eggex sublanguage of Oil to translate to extended regexps: so you can use it with egrep, awk, and sed --regexp-extended.

FWIW this is one reason I designed the Eggex sublanguage of Oil to translate to extended regexps: so you can use it with egrep, awk, and sed --regexp-extended. https://www.oilshell.org/release/latest/doc/eggex.html https://www.oilshell.org/release/latest/doc/eggex.html It really annoys me to have to remember multiple syntaxes for regexes in shell scripts! Also, even if you added Perl syntax to sed today, it wouldn't be available everywhere. Oil isn't available everywhere either but there are some advantages to having the syntax in the shell rather than in every tool. (It's also easy to translate eggex to the BRE syntax or Perl syntax, but nobody has done so yet)