PowerShell to report top 10 results from log file

Ever want to sift through a log file and report on the top 10 occurances of a certain field value? Here is a PowerShell script that will do just that.

I had a log file that contained an IP address in the third field (column index 2 since arrays start at zero in PowerShell). I wanted to know what were the top 10 IPs that were logs. I could call this script like:

./ipcount.ps1 logfile.log 2

When using huge log files, don't forget if you want to redisplay, but not recompute, the results, you can "dot source" the script like:

. ./ipcount.ps1 logfile.log 2

Then $result will always hold the last set of results. Here is the script (3 lines...middle line is really long):

param($file,$index)

$result = gc $file | foreach {$hash=@{}}{$hash[$_.split(',')[[int]$index]] += 1}{$hash.getenumerator()} | sort value -desc | select -first 10

$result

URLs and System.IO.Path

Cool. I just found out that the .NET System.IO.Path static methods like GetFilename and GetDirectory work with internet URLs as well. I was wanting to get just the file name from a URL and the System.Uri class doesn't do this...but Path does. Now ain't that slick.