環境変数PATHの末尾に指定の値を追加する

Add-EnvironmentPath.ps1

<# ++++++++++++++++++++++++++++++++++++++++++++++
環境変数PATHの末尾に指定の値を追加する
+++++++++++++++++++++++++++++++++++++++++++++++++ #>
function Add-EnvironmentPath {
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory = $true, Position = 0)]
        [string] $Path, # 追加する値

        [Parameter(Mandatory = $true, Position = 1)]
        [ValidateSet("User", "Machine")]
        [string]$Target # UserかMachineか選ぶ
    )

    $PathEnv = New-Object System.Collections.ArrayList
    ([System.Environment]::GetEnvironmentVariable("Path", $Target)) -split ';' | ForEach-Object {$PathEnv.Add($_)} | Out-Null
    if ($PathEnv -notcontains $Path) {
        $PathEnv.Add($Path)
        [System.Environment]::SetEnvironmentVariable("Path", ($PathEnv -join ';'), $Target)
    }
    [System.Environment]::GetEnvironmentVariable("Path", $Target)
}