Get HEAD status code

get-head.c

// gcc curl.c -lcurl
#include <stdio.h>
#include <curl/curl.h>

// returns:
// 0 - file does not exists
// 1 - file exists
// -1 - failure
int is_remote_file_exists(const char* url) {
  CURL *curl = curl_easy_init();
  if (curl) {
    /* First set the URL that is about to receive our POST. This URL can
       just as well be a https:// URL if that is what should receive the
       data. */
    curl_easy_setopt(curl, CURLOPT_URL, url);

    /* get us the resource without a body - use HEAD! */
    curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);

    /* Perform the request */
    CURLcode res = curl_easy_perform(curl);
    if (res != CURLE_OK) {
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(res));
       return -1;
    }

    long http_code = 0;
    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);

    printf("status code: %ld\n", http_code);

    /* always cleanup */
    curl_easy_cleanup(curl);
    
    return http_code == 200 ? 1 : 0;
  }

  return -1;
}

int main(void) {
  /* In windows, this will init the winsock stuff */
  curl_global_init(CURL_GLOBAL_ALL);

  int res = is_remote_file_exists("http://example.com/sdgsdgsd");
  printf(res > 0 ? "exists\n" : "not exists or failure\n");
  
  curl_global_cleanup();
  return 0;
}