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CURLOPT_FTPPORT(3) libcurl CURLOPT_FTPPORT(3)
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 will be made actively and the given string will
be used to get the IP address to use for the FTP PORT instruction.
The PORT instruction tells the remote server to connect to our
specified IP address. The string may be a plain IP address, a host
name, 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 thus will not use PORT.
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 will pick a free port. If a range is provided and
all ports in the range are not available, libcurl will report
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 will not use DNS-over-HTTPS even
if CURLOPT_DOH_URL(3) is set.
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
FTP
EXAMPLE
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/old-server/file.txt");
curl_easy_setopt(curl, CURLOPT_FTPPORT, "-");
ret = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
AVAILABILITY
Port range support was added in 7.19.5
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),
ibcurl 8.1.2 April 26, 2023 CURLOPT_FTPPORT(3)