using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?:
(?:[1-9]\d?|1\d{2}|2[01]\d|22[0-3])\. # a group, 1-223 with "".""
(?:(?:[1-9]?\d|1\d{2}|2[0-4]\d|25[0-5])\.){2} # b and c groups 0-255 with "".""
(?:[1-9]?\d|1\d{2}|2[0-4]\d|25[0-5]) # d group, ends with optional netmask instead of "".""
(?:\/(?:[89]|[12]\d|3[0-2]))? # netmask
,?\h? # allow comma separated, optional space between
){1,50}$ # up to 50 IPs";
string input = @"1.1.1.
1.1.1.2
1.1.1.2/23
1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23,1.1.1.2/23";
RegexOptions options = RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace;
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