using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^\*\*([^~*]*?~~(?!~))(?:(?1){2})*[^~*]*?\*\*";
string input = @"MATCH THESE:
** basic ~~ case **
**~~**
** intermediate ~~ ~~ ~~ **
** this ~~ is ~~ more~~ ~~complex ~~ **
BUT NOT THESE:
** three ~~~ tildes **
** even ~~ number ~~ **
**some** **stuff~~more**
**no~~~~~~**
** ~~~~ ~~~~~~ **";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx