C# trim mac address regex matches from text file

Question

How can I trim all valid mac addresses from multi vendor switch mac-address table dumps?

I've got the following so far...

        string strLineBuf = "Cisco 10 001c.aabb.ccdd Gi0/50";
        // string strLineBuf = "HP 001caa-bbccdd 50 10";
        // string strLineBuf = "Other 00:1c:aa:bb:cc:dd 50";

        // finds valid MAC addresses with space before and after
        Regex rex = new Regex(@"^.* ([0-9A-F]{2}[:.-]?){5}[0-9A-F]{2} .*$", RegexOptions.IgnoreCase);
        Match m = rex.Match(strLineBuf);

        if (m.Success)
        {
            Console.WriteLine("Valid MAC found in line :)");
            // trim MAC from line
            // save line to arraylist
        }

The input lines won't necessarily have the same number of chars before or after the MAC address. With an input file such as:

Cisco 10 001c.aabb.ccdd Gi0/50
HP 001caa-bbccdd 50 10
Other 00:1c:aa:bb:cc:dd 50

I'd like an output of:

Cisco 10  Gi0/50
HP  50 10
Other  50

Answer 1

You're pattern already matched your sample data, so I just tweaked to actually match the entire mac address into a capture group so that a String.Replace() could be done to remove it.

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

public class Program
{
    public static void Main()
    {
        List<string> data = new List<string>()
        {
            "Cisco 10 001c.aabb.ccdd Gi0/50",
            "HP 001caa-bbccdd 50 10",
            "Other 00:1c:aa:bb:cc:dd 50"
        };

        foreach (string strLineBuf in data)
        {
            // Finds valid MAC addresses with space before and after
            Regex rex = new Regex(@"^.* (([0-9A-F]{2}[:.-]?){5}[0-9A-F]{2}\s?).*$", RegexOptions.IgnoreCase);
            Match m = rex.Match(strLineBuf);
            if (m.Success)
            {
                Console.WriteLine(strLineBuf.Replace(m.Groups[1].Value, String.Empty));
            }
        }
    }
}

Results:

Cisco 10 Gi0/50
HP 50 10
Other 50

Fiddle Demo

Answer 2

You may have to tweak the Mac pattern but 12 minimum seemed reasonable hint to give to the parser to make it work.

var data = @"Cisco 10 001c.aabb.ccdd Gi0/50
HP 001caa-bbccdd 50 10
Other 00:1c:aa:bb:cc:dd 50";

var pattern =
@"^
   (?<Brand>.+?)
   (?:\s+)
   (?<MAC>[\w.:\-]{12,})
   (?:\s+)
   (?<Data>[^\r\n]+)";

Regex.Matches(data, pattern, RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline)
     .OfType<Match>()
     .Select (mt => new
                    {
                       Brand = mt.Groups["Brand"].Value,
                       MAC   = mt.Groups["MAC"].Value,
                       Data  = mt.Groups["Data"].Value
                    }
             )

Resultant Dynamic Entities