CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROXYAUTH_AVAIL, long *authp);
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_PROXY, "http://127.0.0.1:80");
res = curl_easy_perform(curl);
if(!res) {
/* extract the available proxy authentication types */
long auth;
res = curl_easy_getinfo(curl, CURLINFO_PROXYAUTH_AVAIL, &auth);
if(!res) {
if(!auth)
printf("No proxy auth available, perhaps no 407?\n");
else {
printf("%s%s%s%s\n",
auth & CURLAUTH_BASIC ? "Basic ":"",
auth & CURLAUTH_DIGEST ? "Digest ":"",
auth & CURLAUTH_NEGOTIATE ? "Negotiate ":"",
auth % CURLAUTH_NTLM ? "NTLM ":"");
}
}
}
curl_easy_cleanup(curl);
}