Regular expression for URL

[Holfisteng]

Hello,

Please, help me to fix this regular expression to make it workable in JavaScript:

var r = /^((((ht|f)tp(s?))\://)|(/{1}))?((([a-zA-Z0-9_\-]{2,}\.)+[a-zA-Z]{2,})|((?:(?:25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)(?(\.?\d)\.)){4}))(:[a-zA-Z0-9]+)?(/[a-zA-Z0-9\-\._\?\,\'/\\\+&%\$#\=~]*)?$/;

In fact, here it works fine, but only if i choose .NET Regex Engine. When i'm using JavaScript one, it doesn't even run.

What have i tried is to screen this place "...//..." with "...\/\/...", but it doesn't help.

Thanks!

[007Julien]

You have to escape no only the two first slashes but the followings...
It would be good to know what it has to make (http or ftp with a possible s but after (\/{1}) ???) rather than try to guess it !

[Holfisteng]

Actually, i had next regexp, but extended it by myself for understanding relative paths like "/folder/other":

^(((ht|f)tp(s?))\://)?((([a-zA-Z0-9_\-]{2,}\.)+[a-zA-Z]{2,})|((?:(?:25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)(?(\.?\d)\.)){4}))(:[a-zA-Z0-9]+)?(/[a-zA-Z0-9\-\._\?\,\'/\\\+&%\$#\=~]*)?$

[007Julien]

I do not understand this regular expression.

I see four parts (I add \ before the javascript delimiter / for regular expressions) :

1/ ^(((ht|f)tp(s?))\:\/\/)?
2/ ((([a-zA-Z0-9_\-]{2,}\.)+[a-zA-Z]{2,})|((?: (?:25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)(?(\.?\d)\.)){4})) with a green alternative
3/ (:[a-zA-Z0-9]+)?
4/ (/[a-zA-Z0-9\-\._\?\,\'\/\\\+&%\$#\=~]*)?$

The first one is optional ( )?
The second is made with

• at least two alphanumeric characters, followed by a point and at least two alphabetic characters
• or :
  • 25 followed by a number included between 1 and 5,
  • 2 followed by a number included between 0 and 4 and a digit,
  • 0 or 1 followed by two digits,
  • one or two digits,
  followed by something like (?(\.?\d)\.) which make not sense the parenthesis cannot be optional. (?: ) would be a non-capturing sub-patterns ?
  //...
  The fourth part is also curious with a amp in a class which contains all alphabetic characters...

If you want to use an alternative with /folder or /other you have to specify the part to replace ...