使用正则表达式从字符串中解析字符串

Question

I want to get string from a string with Regex :

Regex regex = new Regex(".signature=(.*)(", RegexOptions.Singleline);
var v = regex.Match(html);
string funcName = v.Groups[1].Value;

This is the a HTML string:

c&&(b.signature=hj(c));

And i want to get the hj , and when i run it i get this exception :

parsing ".signature=(.*)(" - Not enough )'s.

Answer 1

you have to escape special characters. use this:

Regex regex = new Regex(@"\.signature=(.*)\(", RegexOptions.Singleline);
var v = regex.Match(html);
string funcName = v.Result("$1");

you can find a very good explanation about escaping special characters in regex here (2nd paragraph): http://www.regular-expressions.info/characters.html

Edit:

if you search for this specific function in an entire html page, you will have problems, that is because .* is greedy, which means it tries to get as much as possbile (see a good explanation about that here: http://www.regular-expressions.info/repeat.html (3rd paragraph))

a better way would be:

Regex regex = new Regex(@"\.signature=([^\(]+)\(", RegexOptions.Singleline);
var v = regex.Match(html);
string funcName = v.Result("$1");

[^\\(]+ searches for a string of at least 1 character without a ( . that would work on an entire html page