Csharp/C Sharp/Development Class/Matcher

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]?\d\d?         
# OR
 |2[0-4]\d          
# OR
 |25[0-5])          
\.                  
# REPEAT
([01]?\d\d?|2[0-4]\d|25[0-5])\.
# REPEAT
([01]?\d\d?|2[0-4]\d|25[0-5])\.
# REPEAT
([01]?\d\d?|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();
        }
        
    }
}

Is Match successful

using System;
using System.Text.RegularExpressions;
public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])";
        Regex regex = new Regex( pattern );
        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 );
            Console.WriteLine( "Groups are:" );
            foreach( Group g in match.Groups ) {
                Console.WriteLine( "\t{0} at {1}",
                                   g.Value,
                                   g.Index );
            }
            match = match.NextMatch();            
        }
    }
}

MatchEvaluator: Entry Point IP Reverse

using System;
using System.Text;
using System.Text.RegularExpressions;
public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"(?<part1>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part2>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part3>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part4>[01]?\d\d?|2[0-4]\d|25[0-5])";
        Regex regex = new Regex( pattern );
        Match match = regex.Match( "192.168.169.1" );
        MatchEvaluator eval = new MatchEvaluator(EntryPoint.IPReverse );
        Console.WriteLine( regex.Replace("192.168.169.1", eval) );
    }
    static string IPReverse( Match match ) {
        Console.WriteLine( match.Groups["part4"] + "." );
        Console.WriteLine( match.Groups["part3"] + "." );
        Console.WriteLine( match.Groups["part2"] + "." );
        Console.WriteLine( match.Groups["part1"] );
        return "";
    }
}

Match Groups

using System;
using System.Text.RegularExpressions;
public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"(?<part1>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part2>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part3>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"(?<part4>[01]?\d\d?|2[0-4]\d|25[0-5])";
        Regex regex = new Regex( pattern );
        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 );
            Console.WriteLine( "Groups are:" );
            Console.WriteLine( "\tPart 1: {0}",
                               match.Groups["part1"] );
            Console.WriteLine( "\tPart 2: {0}",
                               match.Groups["part2"] );
            Console.WriteLine( "\tPart 3: {0}",
                               match.Groups["part3"] );
            Console.WriteLine( "\tPart 4: {0}",
                               match.Groups["part4"] );
            match = match.NextMatch();
        }
        
    }
}

Match IP address pattern and print out the index

using System;
using System.Text.RegularExpressions;
public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])\." +
                         @"([01]?\d\d?|2[0-4]\d|25[0-5])";
        Regex regex = new Regex( pattern );
        Match match = regex.Match( "192.169.168.1" );
        while( match.Success ) {
            Console.WriteLine( "IP Address found at {0} with " +
                               "value of {1}",
                               match.Index,
                               match.Value );
            match = match.NextMatch();
        }
        
    }
}

Use regular to search an IP address

using System;
using System.Text.RegularExpressions;
public class EntryPoint
{
    static void Main( string[] args ) {
        // Create regex to search for IP address pattern.
        string pattern = @"\d\d?\d?\.\d\d?\d?\.\d\d?\d?\.\d\d?\d?";
        Regex regex = new Regex( pattern );
        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();
        }
        
    }
}