using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"([a-z0-9]{1,4}:+){3,5}[a-z0-9]{1,4}|(?<!id )(?<!\.)\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b(?!\.)";
string input = @"
from mail.example.com (example.com. [213.239.250.131]) by mx.google.com with ESMTPS id xc4si15480310lbb.82.2014.10.26.06.16.58 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Oct 2014 06:16:58 -0700 (PDT)
Received: from ssservices1-1 (192.168.20.142) by mail.supershuttle.com (192.168.20.110) with Microsoft SMTP Server id 14.2.347.0; Tue, 21 Apr 2015
Received: from ssservices1-1 (192.168.20.142) by mail.supershuttle.com (192.168.20.110) with Microsoft SMTP (TLS) Server id 14.2.347.0; Tue, 21 Apr 2015
";
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