1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_FTP_USE_EPSV 5Section: 3 6Source: libcurl 7Protocol: 8 - FTP 9See-also: 10 - CURLOPT_FTPPORT (3) 11 - CURLOPT_FTP_USE_EPRT (3) 12Added-in: 7.9.2 13--- 14 15# NAME 16 17CURLOPT_FTP_USE_EPSV - use EPSV for FTP 18 19# SYNOPSIS 20 21~~~c 22#include <curl/curl.h> 23 24CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_EPSV, long epsv); 25~~~ 26 27# DESCRIPTION 28 29Pass *epsv* as a long. If the value is 1, it tells curl to use the EPSV 30command when doing passive FTP downloads (which it does by default). Using 31EPSV means that libcurl first attempts to use the EPSV command before using 32PASV. If you pass zero to this option, it does not use EPSV, only plain PASV. 33 34The EPSV command is a slightly newer addition to the FTP protocol than PASV 35and is the preferred command to use since it enables IPv6 to be used. Old FTP 36servers might not support it, which is why libcurl has a fallback mechanism. 37Sometimes that fallback is not enough and then this option might come handy. 38 39If the server is an IPv6 host, this option has no effect. 40 41# DEFAULT 42 431 44 45# %PROTOCOLS% 46 47# EXAMPLE 48 49~~~c 50int main(void) 51{ 52 CURL *curl = curl_easy_init(); 53 if(curl) { 54 CURLcode res; 55 curl_easy_setopt(curl, CURLOPT_URL, 56 "ftp://example.com/old-server/file.txt"); 57 58 /* let's shut off this modern feature */ 59 curl_easy_setopt(curl, CURLOPT_FTP_USE_EPSV, 0L); 60 61 res = curl_easy_perform(curl); 62 63 curl_easy_cleanup(curl); 64 } 65} 66~~~ 67 68# %AVAILABILITY% 69 70# RETURN VALUE 71 72Returns CURLE_OK if FTP is supported, and CURLE_UNKNOWN_OPTION if not. 73