@urls = qw[
    http://www.url.com
    http://www.url.com/
    http://www.url.com/cgi.pl?x=y
];;

 m[^( http:// [^/]+ (?: / | $ ) )]x and print "'$1'" for @urls;;
'http://www.url.com'
'http://www.url.com/'
'http://www.url.com/'