PHP Curl CURLOPT_IPRESOLVE
Check you curl version
CURLOPT_IPRESOLVE is available since curl 7.10.8
Try this sample code to test
<?php $version = curl_version();// These are the bitfields that can be used // to check for features in the curl build$bitfields = Array( 'CURL_VERSION_IPV6', 'CURLOPT_IPRESOLVE' );foreach($bitfields as $feature){ echo $feature . ($version['features'] & constant($feature) ? ' matches' : ' does not match'); echo PHP_EOL;}FYI: http://gcov.php.net/PHP_5_3/lcov_html/curl/interface.c.gcov.php