CURLINFO_SCHEME - Man Page

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_SCHEME, char **scheme);

Pass a pointer to a char pointer to receive the pointer to a null-terminated string holding the URL scheme used for the most recent transfer done with this CURL handle. The scheme might also sometimes be referred to as the protocol.

The scheme pointer is NULL or points to private memory. You must not free it. The memory gets freed automatically when you call curl_easy_cleanup(3) on the corresponding curl handle.

The returned scheme might be upper or lowercase. Do comparisons case insensitively.

This functionality affects all supported protocols

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    result = curl_easy_perform(curl);
    if(result == CURLE_OK) {
      char *scheme = NULL;
      curl_easy_getinfo(curl, CURLINFO_SCHEME, &scheme);
      if(scheme)
        printf("scheme: %s\n", scheme); /* scheme: HTTP */
    }
    curl_easy_cleanup(curl);
  }
}

Added in curl 7.52.0

curl_easy_getinfo(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).

CURLINFO_EFFECTIVE_URL(3), CURLINFO_PROTOCOL(3), CURLINFO_RESPONSE_CODE(3), curl_easy_getinfo(3), curl_easy_setopt(3)

curl_easy_getinfo(3), CURLINFO_PROTOCOL(3), CURLOPT_DEFAULT_PROTOCOL(3), CURLOPT_PROTOCOLS_STR(3), CURLOPT_REDIR_PROTOCOLS(3), CURLOPT_REDIR_PROTOCOLS_STR(3).