Adds a given folder to the windows path.

add2path.ps1

#Requires -RunAsAdministrator

param (
    [Parameter(Mandatory=$true)][string]$folder
)

if((Get-Item $folder) -is [System.IO.DirectoryInfo])
{
    $folder = Resolve-Path $folder
}
else{
    Write-Host "Submitted value $folder is not a folder"
    exit
}

Write-Host "Testing $folder to see if it's already in the path" -ForegroundColor Green

$regKey = ([Microsoft.Win32.Registry]::LocalMachine).OpenSubKey("SYSTEM\CurrentControlSet\Control\Session Manager\Environment", $True)
$oldpath = $regKey.GetValue("Path", $Null, "DoNotExpandEnvironmentNames")
$array = $oldpath.Split(";", [System.StringSplitOptions]::RemoveEmptyEntries)
$NewValues = @()

ForEach ($Value in $array)
{
    if ($NewValues -notcontains $folder)
    {
        $NewValues += $Value
    }
    else
    {
        $IsDuplicate = $True
    }
}

if ($IsDuplicate)
{
    Write-Host "Duplicate value found $folder already in path" -ForegroundColor Green
    exit
}
else
{
    Write-Host "Adding new folder to path" -ForegroundColor Green
    $NewValues += $folder
    $NewValue = $NewValues -join ";"
    $regKey.SetValue("Path", $NewValue, [Microsoft.Win32.RegistryValueKind]::ExpandString)
    Write-Host "New PATH entry found and new PATH built removing all duplicates. New Path :" + $NewValue
}