Function PromptGuid
{
    $guid = New-Guid
    Write-Host -NoNewline "Choose a format to copy (r to regen): "
    $op_pos = $host.UI.RawUI.CursorPosition
    Write-Host
    Write-Host "  (enter) : $($guid.ToString())"
    Write-Host "     B    : $($guid.ToString('B'))"
    Write-Host "     N    : $($guid.ToString('N'))"
    Write-Host "     X    : $($guid.ToString('X'))"
    $end_pos = $host.UI.RawUI.CursorPosition

    $host.UI.RawUI.CursorPosition = $op_pos
    $option = ($host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")).Character
    $host.UI.RawUI.CursorPosition = $end_pos

    if ($option -ieq 'r')
    {
        Clear-Host
        return $false
    }

	$isEnter = ([int]$option -eq 13);

    if ($isEnter -or (('b', 'n', 'x') -contains $option))
    {
		if ($isEnter)
		{
			$option = $null
		}

        $guid.ToString($option) | clip

        Write-Host 'Copied.'
        return $true
    }
    else
    {
        Write-Host "Invalid option $option."
        Write-Host
        return $false
    }
}

$exit = $false
while(-not $exit)
{
    $exit = PromptGuid
}