(PHP 4 >= 4.0.2, PHP 5, PHP 7)
curl_version — Gets cURL version information
$age = CURLVERSION_NOW
  ] )Returns information about the cURL version.
age
Returns an associative array with the following elements:
| Indice | Value description | 
|---|---|
| version_number | cURL 24 bit version number | 
| version | cURL version number, as a string | 
| ssl_version_number | OpenSSL 24 bit version number | 
| ssl_version | OpenSSL version number, as a string | 
| libz_version | zlib version number, as a string | 
| host | Information about the host where cURL was built | 
| age | |
| features | A bitmask of the CURL_VERSION_XXX constants | 
| protocols | An array of protocols names supported by cURL | 
Example #1 curl_version() example
This example will check which features that's available in cURL build by using the 'features' bitmask returned by curl_version().
<?php
// Get curl version array
$version = curl_version();
// These are the bitfields that can be used 
// to check for features in the curl build
$bitfields = Array(
            'CURL_VERSION_IPV6', 
            'CURL_VERSION_KERBEROS4', 
            'CURL_VERSION_SSL', 
            'CURL_VERSION_LIBZ'
            );
foreach($bitfields as $feature)
{
    echo $feature . ($version['features'] & constant($feature) ? ' matches' : ' does not match');
    echo PHP_EOL;
}
?>