using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?:([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}(?1)$";
string input = @"0.0.0.0
0.0.0.1
0.0.0.9
0.0.0.19
0.0.0.29
0.0.0.39
0.0.0.49
0.0.0.59
0.0.0.69
0.0.0.79
0.0.0.89
0.0.0.99
0.0.0.100
0.0.0.109
0.0.0.199
0.0.0.200
0.0.0.209
0.0.0.210
0.0.0.219
0.0.0.229
0.0.0.239
0.0.0.249
0.0.0.250
0.0.0.251
0.0.0.253
0.0.0.254
0.0.0.255
0.0.0.256
127.0.0.1
255.255.255.0
192.168.0.1";
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