using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(\d+)(?<!10)\.(\d+)(?<!192\.168)(?<!172\.(1[0-6]|2\d|3[0-1]))\.(\d+)\.(\d+)";
string input = @"74.125.226.134
10.0.1.1
172.16.0.0
172.31.0.1
172.32.0.0
192.168.10.1
104.44.81.79";
foreach (Match m in Regex.Matches(input, pattern))
{
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