Vim-formatted regular expression to match a URL for syntax highlighting

vim_url_regex_syntax_hightlighting.vim

" File: .vim/syntax/rdoc.vim
" RDoc inline links:           protocol   optional  user:pass@       sub/domain                 .com, .co.uk, etc      optional port   path/querystring/hash fragment
"                            ------------ _____________________ --------------------------- ________________________ ----------------- __
syntax match  rdocInlineURL /https\?:\/\/\(\w\+\(:\w\+\)\?@\)\?\([A-Za-z][-_0-9A-Za-z]*\.\)\{1,}\(\w\{2,}\.\?\)\{1,}\(:[0-9]\{1,5}\)\?\S*/
HtmlHiLink rdocInlineURL    htmlLink

I come back to this weekly! Cheers for keeping it in a gist!

Thank you!