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

Windows and *nux treat wildcards differently. *, ? and . are processed in a very complex way by Windows, one's presence or position would change another's meaning. While *nux keeps it simple, all it does is just one simple pattern match. Besides that, Windows matches ? for 0 or 1 chars, Linux matches it for exactly 1 chars.

I didn't find authoritative documents on this matter, here is just my conclusion based on days of tests on Windows 8/XP (command line, dir command to be specific, and the Directory.GetFiles method uses the same rules too) and Ubuntu Server 12.04.1 (ls command). I made tens of common and uncommon cases work, although there'are many failed cases too.

The answer by Gabe works like *nux. If you also want a Windows style one, and are willing to accept the imperfection, then here it is:

    /// <summary>    /// <para>Tests if a file name matches the given wildcard pattern, uses the same rule as shell commands.</para>    /// </summary>    /// <param name="fileName">The file name to test, without folder.</param>    /// <param name="pattern">A wildcard pattern which can use char * to match any amount of characters; or char ? to match one character.</param>    /// <param name="unixStyle">If true, use the *nix style wildcard rules; otherwise use windows style rules.</param>    /// <returns>true if the file name matches the pattern, false otherwise.</returns>    public static bool MatchesWildcard(this string fileName, string pattern, bool unixStyle)    {        if (fileName == null)            throw new ArgumentNullException("fileName");        if (pattern == null)            throw new ArgumentNullException("pattern");        if (unixStyle)            return WildcardMatchesUnixStyle(pattern, fileName);        return WildcardMatchesWindowsStyle(fileName, pattern);    }    private static bool WildcardMatchesWindowsStyle(string fileName, string pattern)    {        var dotdot = pattern.IndexOf("..", StringComparison.Ordinal);        if (dotdot >= 0)        {            for (var i = dotdot; i < pattern.Length; i++)                if (pattern[i] != '.')                    return false;        }        var normalized = Regex.Replace(pattern, @"\.+$", "");        var endsWithDot = normalized.Length != pattern.Length;        var endWeight = 0;        if (endsWithDot)        {            var lastNonWildcard = normalized.Length - 1;            for (; lastNonWildcard >= 0; lastNonWildcard--)            {                var c = normalized[lastNonWildcard];                if (c == '*')                    endWeight += short.MaxValue;                else if (c == '?')                    endWeight += 1;                else                    break;            }            if (endWeight > 0)                normalized = normalized.Substring(0, lastNonWildcard + 1);        }        var endsWithWildcardDot = endWeight > 0;        var endsWithDotWildcardDot = endsWithWildcardDot && normalized.EndsWith(".");        if (endsWithDotWildcardDot)            normalized = normalized.Substring(0, normalized.Length - 1);        normalized = Regex.Replace(normalized, @"(?!^)(\.\*)+$", @".*");        var escaped = Regex.Escape(normalized);        string head, tail;        if (endsWithDotWildcardDot)        {            head = "^" + escaped;            tail = @"(\.[^.]{0," + endWeight +"})?$";        }        else if (endsWithWildcardDot)        {            head = "^" + escaped;            tail = "[^.]{0," + endWeight +"}$";        }        else        {            head = "^" + escaped;            tail = "$";        }        if (head.EndsWith(@"\.\*") && head.Length > 5)        {            head = head.Substring(0, head.Length - 4);            tail = @"(\..*)?" + tail;        }        var regex = head.Replace(@"\*", ".*").Replace(@"\?", "[^.]?") + tail;        return Regex.IsMatch(fileName, regex, RegexOptions.IgnoreCase);    }    private static bool WildcardMatchesUnixStyle(string pattern, string text)    {        var regex = "^" + Regex.Escape(pattern)                               .Replace("\\*", ".*")                               .Replace("\\?", ".")+"$";        return Regex.IsMatch(text, regex);    }

There's a funny thing, even the Windows API PathMatchSpec does not agree with FindFirstFile. Just try a1*., FindFirstFile says it matches a1, PathMatchSpec says not.