求助：Curl返回成功，但显示500错误，内部服务器错误

我使用 curl 访问 web 服务时，有时会得到响应，但有时会因为内部服务器错误而失败，即使我实际上收到了预期的 xml 文件。问题出在哪？

$header = array(
                  "Content-type: text/xml;charset=\"utf-8\"",
                  "Accept: text/xml",
                  "Cache-Control: no-cache",
                  "Pragma: no-cache",
                  "Content-length: ".strlen($send),
                );

            $URL = 'https:ip:port/xxxxx';

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0); 
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 60);
            curl_setopt($ch, CURLOPT_TIMEOUT, 120);
            curl_setopt($ch, CURLOPT_URL, $URL );
            curl_setopt($ch, CURLOPT_POST, true );
            curl_setopt($ch, CURLOPT_HTTPHEADER, $header); //array('Content-Type: text/xml'));
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true );
            curl_setopt($ch, CURLOPT_POSTFIELDS, $send );
            //curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13');
try {
                $result = curl_exec($ch);        
                curl_close($ch);
                $f = fopen("./Response.xml", "w");
                fwrite($f, $result);
                fclose($f);           
            } 
            catch (Exception $e) {
                $payments = "<DIV class = 'alert alert-danger'>Failed Transaction. Please try again</DIV>";
                     $error = Date("Y-m-d h:i:s")."
Error Number:".curl_errno($soap_do)."
";
                     $error .=  "Error String:".curl_error($ch)."
 Matrucule: ".$matricule."
------------------------
";
                     $f = fopen("./Payment_Error_Log.txt", "w");
                     fwrite($f, $error);
                     fclose($f);
            }

You have a problem with the server side code.. https:ip:port/xxxxx is returning error 500 when POSTing to it.

Could be a problem with the web service or with the specific parameters you're POSTing ($send).