Tribblix: manual page: CURLOPT

CURLOPT_LOCALPORT(3) Introduction to Library Functions CURLOPT_LOCALPORT(3)

NAME

CURLOPT_LOCALPORT - local port number to use for socket

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORT, long port);

DESCRIPTION

Pass a long. This sets the local port number of the socket used for
the connection. This can be used in combination with
CURLOPT_INTERFACE(3) and you are recommended to use
CURLOPT_LOCALPORTRANGE(3) as well when this option is set. Valid port
numbers are 1 - 65535.

DEFAULT

0, disabled - use whatever the system thinks is fine

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
curl_easy_setopt(curl, CURLOPT_LOCALPORT, 49152L);
/* and try 20 more ports following that */
curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 20L);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}

AVAILABILITY

Added in curl 7.15.2

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).