[soap] How to do a SOAP wsdl web services call from the command line

For Windows users looking for a PowerShell alternative, here it is (using POST). I've split it up onto multiple lines for readability.

$url = 'https://sandbox.mediamind.com/Eyeblaster.MediaMind.API/V2/AuthenticationService.svc'
$headers = @{
    'Content-Type' = 'text/xml';
    'SOAPAction' = 'http://api.eyeblaster.com/IAuthenticationService/ClientLogin'
}
$envelope = @'
    <Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/">
        <Body>
            <yourEnvelopeContentsHere/>
        </Body>
    </Envelope>
'@     # <--- This line must not be indented

Invoke-WebRequest -Uri $url -Headers $headers -Method POST -Body $envelope