Michael Könings Blog

How-To: add geographical information to IIS log files with LINQ

LINQ in action: a real life problem, solved with a few lines of easy-to-read code. In my last post, I promised to provide a solution to enhance the information we can derive from IIS logs with the help of Log Parser. All you need is the free Geo-IP database (updated frequently) that can be found here plus the free C# API that is provided by these generous folks.

create a (less messy :-) ) little command line program that has a  LINQ statement like this:

using System;
using System.Collections.Generic;
using System.Linq;


namespace CountryLookupProj
{
    class SumColumns
    {
        static void Main(string[] args)
        {
            string[] lines = System.IO.File.ReadAllLines(args[0]);

            int exam = int.Parse(args[1]);


            AddSingleColumn(lines, exam - 1);
            Console.WriteLine();
            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }

        static void AddSingleColumn(IEnumerable<string> strs, int examNum)
        {
            CountryLookup countryLookup = 
                new CountryLookup(@"C:\Stuff\GeoLiteCity\Geoip.dat");
            var columnQuery =
                from line in strs
                let x = line.Split(';')
                select countryLookup.lookupCountryName(x[examNum]) 
                       + ";" + String.Join(";", x);

            System.IO.File.WriteAllLines(@"c:\temp\output.log",
                                         columnQuery.ToArray());

        }

    }
}

run it like this:

c:>\myprogram.exe "mylogfile.CSV" 1

the 1 is the (one-based) position of the ip-address column in your CSV-file.

thanks for the inspiration found here (MSDN)