/
( # start capture url
(?:(?:(?:ht|f)tps?\:)\/\/?|(?:www\.)) # start with http or www
(?:\s?[:\w?=%&+-]+ # need some chars in url, allow spaces.
(?:(?:(?:\.)|(?:\/(?:\/)?)))? # can have ., / or // inside urls.
)+ # allow repeat alternating pattern of chars and delimiters
) # end capture url
/
gmx