CURLOPT_FTP_USE_EPSV - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_EPSV, long epsv);

Pass epsv as a long. If the value is 1, it tells curl to use the EPSV command when doing passive FTP downloads (which it does by default). Using EPSV means that libcurl first attempts to use the EPSV command before using PASV. If you pass zero to this option, it does not use EPSV, only plain PASV.

The EPSV command is a slightly newer addition to the FTP protocol than PASV and is the preferred command to use since it enables IPv6 to be used. Old FTP servers might not support it, which is why libcurl has a fallback mechanism. Sometimes that fallback is not enough and then this option might come handy.

If the server is an IPv6 host, this option has no effect.

1

This functionality affects ftp only

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL,
                     "ftp://example.com/old-server/file.txt");

    /* let's shut off this modern feature */
    curl_easy_setopt(curl, CURLOPT_FTP_USE_EPSV, 0L);

    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
  }
}

Added in curl 7.9.2

Returns CURLE_OK if FTP is supported, and CURLE_UNKNOWN_OPTION if not.

CURLOPT_FTPPORT(3), CURLOPT_FTP_USE_EPRT(3)

curl_easy_setopt(3), CURLOPT_FTP_CREATE_MISSING_DIRS(3), CURLOPT_FTPPORT(3), CURLOPT_FTP_USE_EPRT(3), CURLOPT_FTP_USE_PRET(3), libcurl-symbols(3), libcurl-tutorial(3).