Over at CodeReview this question was answered quite splendidly.
function replaceURLWithHTMLLinks(text) {
var re = /(\(.*?)?\b((?:https?|ftp|file):\/\/[-a-z0-9+&@#\/%?=~_()|!:,.;]*[-a-z0-9+&@#\/%=~_()|])/ig;
return text.replace(re, function(match, lParens, url) {
var rParens = '';
lParens = lParens || '';
// Try to strip the same number of right parens from url
// as there are left parens. Here, lParenCounter must be
// a RegExp object. You cannot use a literal
// while (/\(/g.exec(lParens)) { ... }
// because an object is needed to store the lastIndex state.
var lParenCounter = /\(/g;
while (lParenCounter.exec(lParens)) {
var m;
// We want m[1] to be greedy, unless a period precedes the
// right parenthesis. These tests cannot be simplified as
// /(.*)(\.?\).*)/.exec(url)
// because if (.*) is greedy then \.? never gets a chance.
if (m = /(.*)(\.\).*)/.exec(url) ||
/(.*)(\).*)/.exec(url)) {
url = m[1];
rParens = m[2] + rParens;
}
}
return lParens + "" + url + "" + rParens;
});
}
Note: I had errors with the "@" symbol in the "var re" - I just replaced it with @@