CURLcode curl_easy_setopt(CURL *handle, CURLOPT_NOPROXY, char *noproxy);
If the name in the noproxy list has a leading period, it is a domain match against the provided host name. This way ".example.com" will switch off proxy use for both "www.example.com" as well as for "foo.example.com".
Setting the noproxy string to "" (an empty string) will explicitly enable the proxy for all host names, even if there is an environment variable set for it.
Enter IPv6 numerical addresses in the list of host names without enclosing brackets:
"example.com,::1,localhost"
IPv6 numerical addresses are compared as strings, so they will only match if the representations are the same: "::1" is the same as "::0:1" but they don't match.
The application does not have to keep the string around after setting this option.
CURL *curl = curl_easy_init();
if(curl) {
/* accept various URLs */
curl_easy_setopt(curl, CURLOPT_URL, input);
/* use this proxy */
curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy:80");
/* ... but make sure this host name is not proxied */
curl_easy_setopt(curl, CURLOPT_NOPROXY, "www.example.com");
curl_easy_perform(curl);
}