regex

• https://regex101.com/
• can also use -r or -E in sed

PCRE

Oniguruma Regex

• docs: https://github.com/kkos/oniguruma/blob/master/doc/RE
• library for regex that has features from many different regular regexes
• jq has some additional docs at https://github.com/stedolan/jq/wiki/Docs-for-Oniguruma-Regular-Expressions-(RE.txt)