CURLOPT_ADDRESS_SCOPE(3) Library Functions Manual CURLOPT_ADDRESS_SCOPE(3)
NAME
CURLOPT_ADDRESS_SCOPE - scope id for IPv6 addresses
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ADDRESS_SCOPE, long scope);
DESCRIPTION
Pass a long specifying the scope id value to use when connecting to
IPv6 addresses.
DEFAULT
0
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
#include <net/if.h> /* for if_nametoindex() */
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
long my_scope_id;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
my_scope_id = if_nametoindex("eth0");
curl_easy_setopt(curl, CURLOPT_ADDRESS_SCOPE, my_scope_id);
result = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
AVAILABILITY
Added in curl 7.19.0
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). Returns CURLE_BAD_FUNCTION_ARGUMENT if set to a
negative value.
SEE ALSO
CURLOPT_DEBUGFUNCTION(3), CURLOPT_STDERR(3)
libcurl 2026-03-23 CURLOPT_ADDRESS_SCOPE(3)
curl 8.19.0 - Generated Thu Mar 26 18:21:13 CDT 2026