检查网站是否可用

执行 cURL 请求以检查网站是否存在/在线

技术 #1

<?php

       if (isDomainAvailible('https://css-tricks.cn'))
       {
               echo "Up and running!";
       }
       else
       {
               echo "Woops, nothing found there.";
       }

       //returns true, if domain is availible, false if not
       function isDomainAvailible($domain)
       {
               //check, if a valid url is provided
               if(!filter_var($domain, FILTER_VALIDATE_URL))
               {
                       return false;
               }

               //initialize curl
               $curlInit = curl_init($domain);
               curl_setopt($curlInit,CURLOPT_CONNECTTIMEOUT,10);
               curl_setopt($curlInit,CURLOPT_HEADER,true);
               curl_setopt($curlInit,CURLOPT_NOBODY,true);
               curl_setopt($curlInit,CURLOPT_RETURNTRANSFER,true);

               //get answer
               $response = curl_exec($curlInit);

               curl_close($curlInit);

               if ($response) return true;

               return false;
       }
?>

查看演示

技术 #2

<?php
function Visit($url){
       $agent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";$ch=curl_init();
       curl_setopt ($ch, CURLOPT_URL,$url );
       curl_setopt($ch, CURLOPT_USERAGENT, $agent);
       curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
       curl_setopt ($ch,CURLOPT_VERBOSE,false);
       curl_setopt($ch, CURLOPT_TIMEOUT, 5);
       curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, FALSE);
       curl_setopt($ch,CURLOPT_SSLVERSION,3);
       curl_setopt($ch,CURLOPT_SSL_VERIFYHOST, FALSE);
       $page=curl_exec($ch);
       //echo curl_error($ch);
       $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
       curl_close($ch);
       if($httpcode>=200 && $httpcode<300) return true;
       else return false;
}
if (Visit("http://www.google.com"))
       echo "Website OK"."n";
else
       echo "Website DOWN";
?>

技术 #3

<?php
       ini_set("default_socket_timeout","05");
       set_time_limit(5);
       $f=fopen("https://css-tricks.cn","r");
       $r=fread($f,1000);
       fclose($f);
       if(strlen($r)>1) {
       echo("<span class='online'>Online</span>");
       }
       else {
       echo("<span class='offline'>Offline</span>");
       }
?>