Regular expression ^(?:https?:)?(?:\/\/)?(?:+@)?(?:www\.)?(+) used below extracts domain with subdomains out of a full url. It skips protocol (ex: https:), "//", "@", www subdomain and then captures everything (ex: domain) before ":" or "/" or end of line.

This regex can capture any column name from a select query. Be the original name, like are named on table, renamed with a reserved word AS or even without explicit AS. Go on, and test with your query ;)

This regular expression is used to validated the filename of Gateway plugins.

Matches a variable with the following syntax; = example string foo = ...