How to resolve cURL Error (7): couldn't connect to host?

Question

I send an item code to a web service in xml format using cUrl(php). I get the correct response in localhost, but when do it server it shows

cURL Error (7): couldn't connect to host

And here's my code:

function xml_post($post_xml, $url)
{
    $user_agent = $_SERVER['HTTP_USER_AGENT'];

    $ch = curl_init();    // initialize curl handle
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($ch, CURLOPT_URL, $url); 
    curl_setopt($ch, CURLOPT_FAILONERROR, 1);          
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);    
    curl_setopt($ch, CURLOPT_RETURNTRANSFER,1); 
    curl_setopt($ch, CURLOPT_TIMEOUT, 50); 
    curl_setopt($ch, CURLOPT_POSTFIELDS, $post_xml); 
    curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
//  curl_setopt($ch, CURLOPT_PORT, $port);          

    $data = curl_exec($ch);
    $curl_errno = curl_errno($ch);
    $curl_error = curl_error($ch);
    if ($curl_errno > 0) {
            echo "cURL Error ($curl_errno): $curl_error\n";
    } else {
            echo "Data received\n";
    }
    curl_close($ch);

    echo $data;
}

I send the item code to the tally and fetch the details from it. I tried using both the versions php 4+ and php5+, nothing works out Any solution.

Answer 1

CURL error code 7 (CURLE_COULDNT_CONNECT)

is very explicit ... it means Failed to connect() to host or proxy.

The following code would work on any system:

$ch = curl_init("http://google.com");    // initialize curl handle
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
print($data);

If you can not see google page then .. your URL is wrong or you have some firewall or restriction issue.