Get all ampersands, but omits the ampersands that are part of any HTML entities.

Without lookaround, this regular expression also accepts P and PT as valid duration strings. If your library supports lookaround, I recommend that you use Full ISO 8601 Duration with lookaround (also in the library) instead, which will also reject P and PT.

With lookaround, this regular expression will reject P and PT as invalid duration strings. If your library does not support lookaround, I recommend that you use Full ISO 8601 Duration without lookaround (also in the library) instead, with the caveat that you will need to verify the string is not P o...

https://emailregex.com/

For each that it founds, it inserts a <![CDATA[ ... ]]>

Telephone number strict international section :- starting with '+' or '00' flexible local section for wider international and allows spaces for visual formatting Close enough for many requirements. Tweak to match your country/circumstances better. ...

(\([0-9]{2}\)\s?[0-9]{4,5}-?[0-9]{3,4})|([0-9]{10,11})|([0-9]{2}\s?[0-9]{8,9})

Extracts the flag option information from a bash 'COMMAND --help'.

This regular expression will match the following: 0 1-39 Integers Mixed numbers of the form x y/8 or x-y/8 where x is an integer between 1 & 9 and y is an integer between 0 & 7 xx y/8 or xx-y/8 where xx is an integer between 1 & 39 and y is an integer between 0 & 7...

For more background, refer to: http://codel10n.com/what-is-correct-locale-tag-en_us-vs-en-us/