Need to perform Wildcard (*,?, etc) search on a string using Regex

Question

I need to perform Wildcard (*, ?, etc.) search on a string. This is what I have done:

string input = \"Message\";
string pattern =          


        

Answer 1

You must escape special Regex symbols in input wildcard pattern (for example pattern *.txt will equivalent to ^.*\.txt$) So slashes, braces and many special symbols must be replaced with @"\" + s, where s - special Regex symbol.

Answer 2

You can do a simple wildcard mach without RegEx using a Visual Basic function called LikeString.

using Microsoft.VisualBasic;
using Microsoft.VisualBasic.CompilerServices;

if (Operators.LikeString("This is just a test", "*just*", CompareMethod.Text))
{
  Console.WriteLine("This matched!");
}

If you use CompareMethod.Text it will compare case-insensitive. For case-sensitive comparison, you can use CompareMethod.Binary.

More info here: http://www.henrikbrinch.dk/Blog/2012/02/14/Wildcard-matching-in-C

MSDN: http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.compilerservices.operators.likestring%28v=vs.100%29.ASPX

Answer 3

I think @Dmitri has nice solution at Matching strings with wildcard https://stackoverflow.com/a/30300521/1726296

Based on his solution, I have created two extension methods. (credit goes to him)

May be helpful.

public static String WildCardToRegular(this String value)
{
        return "^" + Regex.Escape(value).Replace("\\?", ".").Replace("\\*", ".*") + "$";
}

public static bool WildCardMatch(this String value,string pattern,bool ignoreCase = true)
{
        if (ignoreCase)
            return Regex.IsMatch(value, WildCardToRegular(pattern), RegexOptions.IgnoreCase);

        return Regex.IsMatch(value, WildCardToRegular(pattern));
}

Usage:

string pattern = "file.*";

var isMatched = "file.doc".WildCardMatch(pattern)

or

string xlsxFile = "file.xlsx"
var isMatched = xlsxFile.WildCardMatch(pattern)

Answer 4

All upper code is not correct to the end.

This is because when searching zz*foo* or zz* you will not get correct results.

And if you search "abcd*" in "abcd" in TotalCommander will he find a abcd file so all upper code is wrong.

Here is the correct code.

public string WildcardToRegex(string pattern)
{             
    string result= Regex.Escape(pattern).
        Replace(@"\*", ".+?").
        Replace(@"\?", "."); 

    if (result.EndsWith(".+?"))
    {
        result = result.Remove(result.Length - 3, 3);
        result += ".*";
    }

    return result;
}