这个正则表达式怎么了

Question

I'm doing some experiments with regular expressions and I don't know why the regex don't match.

string line is one line from a file. A line which should match is this

["boxusers:settings/user[boxuser11]/name"] = "username", 

The number of the boxuser and the value could be different, so I tried to find a regular expression

My code is this:

string user;
string patternUser = "[\"boxusers:settings/user[boxuser\\d{2,}]/name\"] = \"";
if (Regex.Match(line,patternUser).Success)
   user = Regex.Replace(Regex.Replace(line, patternUser, String.Empty), ",*", String.Empty);

So I think \\d{2,0} should be a number with two digits and the rest is just the same. But the regex just don't match.

What's going wrong?

Answer 1

Square brackets have a special significance in regular expressions. You need to escape them with a backslash.

var line = @"[""boxusers:settings/user[boxuser11]/name""] = ""username"", ";
string patternUser = @"\[""boxusers:settings/user\[boxuser\d{2,}\]/name""\] = """;
Console.WriteLine(Regex.Match(line, patternUser).Success);

If you don't want to use verbatim strings, you'll need to use two backslashes to escape each regex metacharacter (the first to escape the second).