Question

I’m trying to remove illegal chars from a string that represent path or filename in windows.

Here is the code i used for testing:

        string pattern = "([\", \\, <,>, :, /, ?,|,*])";
        string[] names = { "o\"ne", "t\\wo", "thr<ee", "fo>ur", "fi:ve", "si/x", "sev?en", "ei|ght", "ni*ne" };
        foreach (String name in names)
        {
            Console.WriteLine(Regex.Replace(name, pattern, String.Empty));
        }

I get all prints okay, except “two” that writes like this: t\wo.
I’ve tried putting an asterisk outside the parenthesis and got the same result.

What should i do?

Thank You.

Answer 1

You’ll need to double escape the backslash in your regex pattern; the reason being that the backslash character is used to indicate character groups in regexes (e.g., \d to represent digits). To match on a backslash, you use the notation \\. This then has to be escaped in the .NET string.

In short, change \\ to \\\\.