Enable the pret command
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_PRET, long enable);
Pass a long. If the value is 1, it tells curl to send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non-standard command for directory listings as well as up and downloads in PASV mode. Has no effect when using the active FTP transfers mode.
Added in 7.20.0
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.