是什么阻止了 fsockopen？

经过半天的努力，我终于通过转换这个函数来让reCAPTCHA工作：

function _recaptcha_http_post($host, $path, $data, $port = 80) {

 $req = _recaptcha_qsencode ($data);

 $http_request  = "POST $path HTTP/1.0\r\n";
 $http_request .= "Host: $host\r\n";
 $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
 $http_request .= "Content-Length: " . strlen($req) . "\r\n";
 $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
 $http_request .= "\r\n";
 $http_request .= $req;

 $response = "";
 if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
  die ("Could not open socket");
 }

 fwrite($fs, $http_request);

 while ( !feof($fs) )
  $response .= fgets($fs, 1160); // One TCP-IP packet
 fclose($fs);
 $response = explode("\r\n\r\n", $response, 2);
 return $response;
}

to:

function _recaptcha_http_post($host, $path, $data, $port = 80) {
 $req = _recaptcha_qsencode ($data);
 $request = curl_init("http://".$host.$path);

 curl_setopt($request, CURLOPT_USERAGENT, "reCAPTCHA/PHP");
 curl_setopt($request, CURLOPT_POST, true);
 curl_setopt($request, CURLOPT_POSTFIELDS, $req);
 curl_setopt($request, CURLOPT_RETURNTRANSFER, true);

 $response = curl_exec($request);
 return $response;
}

基本上，我有兴趣找出原因curl工作同时fsockopen失败并显示“无法打开套接字”。谢谢。

此外：套接字支持已启用。

我可能是错的，但你使用$port = 80 in fsockopen()而在cURL如果根本不使用该变量。尝试连接时我遇到了同样的问题SSL via port 80而不是端口443;据我所知，cURL checks SSL默认情况下并进行相应连接。

另外，尝试运行cURL with CURLOPT_VERBOSE看看它做了什么。