通过GET的PHP CURL Web服务不返回任何内容

I have a simple PHP web service sitting on our server.

I am able to connect to this service without any errors using the following code (I've removed our domain):

$service_url = '*** ADDRESS REDACTED! *** /getroomsforcategories.php';

$curl = curl_init();
$curl_post_data = array(
    "categoryids" => 1
    );
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($curl, CURLOPT_URL,$service_url."?categoryids=1"); 
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($curl, CURLOPT_CAINFO, dirname(__FILE__) . "/cacert.pem");
$curl_response = curl_exec($curl);
if ($curl_response===false)
    echo "<p>Error ".curl_errno($curl)." - ".curl_error($curl);
else
{
    echo "<pre>The CURL information: 
";
    print_r(curl_getinfo($curl));
    echo "The response using cURL was: 
";
    print_r($curl_response);
    echo "</pre>";
    curl_close($curl);
}

I get no error from this, it seems to connect just fine (returns HTTP code 200).

The curl info displays as follows:

Array
(
    [url] => *** REDACTED *** /getroomsforcategories.php?categoryids=1
    [content_type] => text/html
    [http_code] => 200
    [header_size] => 348
    [request_size] => 120
    [filetime] => -1
    [ssl_verify_result] => 0
    [redirect_count] => 0
    [total_time] => 0.125
    [namelookup_time] => 0
    [connect_time] => 0
    [pretransfer_time] => 0.109
    [size_upload] => 0
    [size_download] => 0
    [speed_download] => 0
    [speed_upload] => 0
    [download_content_length] => 0
    [upload_content_length] => 0
    [starttransfer_time] => 0.125
    [redirect_time] => 0
    [certinfo] => Array
        (
        )

    [redirect_url] => 
)

However, the curl response is completely empty.

The web service itself works fine - it is called throughout our software via AJAX using jQuery and works perfectly.

Any ideas on something I'm missing??

As a note, HTTP status codes have no correlation with the content length of the body returned. You may very well have a HTTP 200... but with a content length of 0 (which seems to be the case here? "download_content_length" is 0).

Have you checked on the server side to see what the problem might be here? (Oh, and since I assume this is over SSL, you might want to set 'CURLOPT_SSL_VERIFYPEER' to false, just to see if this is a problem with curl being unable to verify the certificate)