Define multiline patterns

   

using System;
using System.Text.RegularExpressions;

public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"
# First part match
([01]?dd?         
# OR
 |2[0-4]d          
# OR
 |25[0-5])          
.                  

# REPEAT
([01]?dd?|2[0-4]d|25[0-5]).

# REPEAT
([01]?dd?|2[0-4]d|25[0-5]).

# REPEAT
([01]?dd?|2[0-4]d|25[0-5])
";
        Regex regex = new Regex( pattern,
                       RegexOptions.IgnorePatternWhitespace );
        Match match = regex.Match( "192.168.169.1" );
        while( match.Success ) {
            Console.WriteLine( "IP Address found at {0} with " +
                               "value of {1}",
                               match.Index,
                               match.Value );

            match = match.NextMatch();
        }
        
    }
}