[PHP] 使用 CURL 測試 Remote Resource Availability @ Ubuntu 14.04

有些程式跑在對岸，就該測測網路是否可取得啦

<?php
function checkRemoteResourceAvailability($target_url) {
        $ch = curl_init($target_url);
        curl_setopt($ch, CURLOPT_NOBODY, true);
        $status = curl_exec($ch) !== false && curl_getinfo($ch, CURLINFO_HTTP_CODE) == 200;
        curl_close($ch);
        return $status;
}

echo checkRemoteResourceAvailability('http://tw.yahoo.com/favicon.ico') ? "ok" : "not available";