PowerShell function that can report the contributiors of a git repo on disk

get-contributors.ps1

<#
.SYNOPSIS
This can be used to get a list of the contributors for a git repo (folder).

Inspired by http://ayende.com/blog/4532/extracting-a-list-of-committers-from-git.

.EXAMPLE
Get-ChildItem .\ -Directory -Exclude .git | Get-Contributors -verbose| select -unique -verbose|sort
#>
function Get-Contributors{
    [cmdletbinding()]
    param(
        [Parameter(Mandatory=$true,Position=0,ValueFromPipeline=$true)]
        [string[]]$gitfolders
    )
    process{   
        foreach($gitfolder in $gitfolders){
            'start on folder [{0}]' -f $gitfolder | Write-Verbose
            Push-Location

            Set-Location $gitfolder
            # get latest to ensure the most up to date list
            'git pull' | Write-Verbose
            &git pull | Out-Null
            'git log --raw' | Write-Verbose
            $authors = (git log --raw | 
                            Where-Object {$_.StartsWith("Author:")} | 
                            % {$_.TrimStart("Author: ")  -replace '\s<\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b.',''} | 
                            Select-Object -Unique)
            "authors:`n[{0}]" -f ($authors -join "`n" ) | Write-Verbose
            $authors
            Pop-Location
        }
    }
}