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.

       You disable PORT again and go back to using the passive version by setting this option to NULL.

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

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)

libcurl                                            2024-12-11                                 CURLOPT_FTPPORT(3)