PHP实现批量检测网站是否能够正常打开的方法

<?php//设置最大执行时间是 120秒ini_set('max_execution_time',120);function httpcode($url){  $ch = curl_init();  $timeout = 3;  curl_setopt($ch,CURLOPT_FOLLOWLOCATION,1);  curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);  curl_setopt($ch, CURLOPT_HEADER, 1);  curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);  curl_setopt($ch,CURLOPT_URL,$url);  curl_exec($ch);  return $httpcode = curl_getinfo($ch,CURLINFO_HTTP_CODE);  curl_close($ch);}$check_web = array('http://www.vevb.com/','http://sucai.vevb.com/','http://idc.vevb.com/','http://news.vevb.com/','http://bbs.vevb.com/','http://demo.vevb.com/',);for($i=0;$i<count($check_web);$i++){  echo $check_web[$i].' -> '.httpcode($check_web[$i]).'<br>';}?>