200 HTTP CODE at non-url strings

问题

$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);

I'm using cUrl at my project. I'm getting HTTP CODE of web sites. But when i try "asdasd" ($url="asdasd") , returned HTTP CODE is 200 . But "asdasd" isn't a web site. Why HTTP CODE is 200 ?

回答1:

You might want to check the return value from curl_exec first. It says in the manual:

Returns TRUE on success or FALSE on failure. However, if the CURLOPT_RETURNTRANSFER option is set, it will return the result on success, FALSE on failure.

For curl_getinfo there's a side note:

Information gathered by this function is kept if the handle is re-used. This means that unless a statistic is overridden internally by this function, the previous info is returned.

So that HTTP 200 might well be the result of a previous cURL invocation.

回答2:

Another possible error can happen if you develop in local and you use custom managed DNS services, then you probably can get some managed error pages like OpenDNS is doing.

来源：https://stackoverflow.com/questions/4627577/200-http-code-at-non-url-strings