Question

I’m currently facing a (little) blocking issue. I’d like to replace a substring by one another using regular expression. But here is the trick : I suck at regex.

Regex.Replace(contenu, "Request.ServerVariables("*"))",
                       "ServerVariables('test')");

Basically I’d like to replace whatever is between the ” by “test”. I tried “.{*}” as a pattern but it doesn’t work.

Could you give me some tips, I’d appreciate it!

Answer 1

There are several issues you need to take care of.

1. You are using special characters in your regex (., parens, quotes) — you need to escape these with a slash. And you need to escape the slashes with another slash as well because we ‘re in a C# string literal, unless you prefix the string with @ in which case the escaping rules are different.
2. The expression to match “any number of whatever characters” is .*. In this case, you would want to match any number of non-quote characters, which is [^"]*.
3. In contrast to (1) above, the replacement string is not a regular expression so you don’t want any slashes there.
4. You need to store the return value of the replace somewhere.

The end result is

var result = Regex.Replace(contenu,
                           @"Request\.ServerVariables\(""[^""]*""\)",
                           "Request.ServerVariables('test')");