HTTP HTTP GET --write-out # Server-side HTTP/1.1 200 OK Content-Length: 3 Connection: close hi # Client-side http --write-out with %{onerror} and %{urlnum} to stderr http://non-existing-host.haxx.se:%NOLISTENPORT/we/want/our/1188 http://%HOSTIP:%HTTPPORT/we/want/our/1188 -w '%{onerror}%{stderr}%{urlnum} says %{exitcode} %{errormsg}\n' -s # Verify data after the test has been "shot" GET /we/want/our/1188 HTTP/1.1 Host: %HOSTIP:%HTTPPORT User-Agent: curl/%VERSION Accept: */* 0 says 6 Could not resolve host: non-existing-host.haxx.se