NAME

       CURLOPT_FTPPORT - make FTP transfer active

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTPPORT, char *spec);

DESCRIPTION

       Pass  a  pointer  to  a  null-terminated  string  as  parameter. It specifies that the FTP
       transfer should be made actively and the given string is used to get the IP address to use
       for the FTP PORT instruction.

       The  PORT  instruction  tells  the  remote  server to do a TCP connect to our specified IP
       address. The string may be a plain IP address, a hostname, a network interface name (under
       Unix)  or  just  a  '-'  symbol  to  let the library use your system's default IP address.
       Default FTP operations are passive, and does not use the PORT command.

       The address can be followed by a ':' to specify a port, optionally followed by  a  '-'  to
       specify  a port range. If the port specified is 0, the operating system picks a free port.
       If a range is provided and all ports in the  range  are  not  available,  libcurl  reports
       CURLE_FTP_PORT_FAILED  for  the  handle.  Invalid  port/range  settings  are ignored. IPv6
       addresses followed by a port or port range have to be in brackets. IPv6 addresses  without
       port/range specifier can be in brackets.

       Examples with specified ports:

       eth0:0
       192.168.1.2:32000-33000
       curl.se:32123
       [::1]:1234-4567

       We  strongly advise against specifying the address with a name, as it causes libcurl to do
       a blocking name resolve call to retrieve the IP address. That name resolve operation  does
       not use DNS-over-HTTPS even if CURLOPT_DOH_URL(3) is set.

       Using  anything  else  than  "-" for this option should typically only be done if you have
       special knowledge and confirmation that it works.

       The application does not have to keep the string around after setting this option.

       Using this option multiple times makes the last set string override the previous ones. You
       disable  PORT  again  and  go  back to using the passive version by setting this option to
       NULL.

DEFAULT

       NULL

PROTOCOLS

       This functionality affects ftp only

EXAMPLE

       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");
           curl_easy_setopt(curl, CURLOPT_FTPPORT, "-");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in curl 7.1

RETURN VALUE

       Returns  CURLE_OK  if  the  option  is  supported,   CURLE_UNKNOWN_OPTION   if   not,   or
       CURLE_OUT_OF_MEMORY if there was insufficient heap space.

SEE ALSO

       CURLOPT_FTP_USE_EPRT(3), CURLOPT_FTP_USE_EPSV(3)