Listen on a tcp port

tcp-listener-trace.ps1

function Trace-Port([string]$IPAddress="127.0.0.1", [int]$Port=80, [switch]$Echo=$false){
    $listener = new-object System.Net.Sockets.TcpListener([System.Net.IPAddress]::Parse($IPAddress), $port)
    $listener.start()
    [byte[]]$bytes = 0..255|%{0}
    write-host "Waiting for a connection on port $port..."
    $client = $listener.AcceptTcpClient()
    write-host "Connected from $($client.Client.RemoteEndPoint)"
    $stream = $client.GetStream()
    while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0)
    {
        $bytes[0..($i-1)]|%{$_}
        if ($Echo){$stream.Write($bytes,0,$i)}
    }
    $client.Close()
    $listener.Stop()
    write-host "Connection closed."
}