I need to make a SOAP webservice call to https://sandbox.mediamind.com/Eyeblaster.MediaMind.API/V2/AuthenticationService.svc?wsdl and to use the operation ClientLogin while
curl --header "Content-Type: text/xml;charset=UTF-8" --header "SOAPAction:ACTION_YOU_WANT_TO_CALL" --data @FILE_NAME URL_OF_THE_SERVICE
Above command was helpful for me
Example
curl --header "Content-Type: text/xml;charset=UTF-8" --header "SOAPAction:urn:GetVehicleLimitedInfo" --data @request.xml http://11.22.33.231:9080/VehicleInfoQueryService.asmx
More info