CURLINFO_CONDITION_UNMET(3) Library Functions Manual CURLINFO_CONDITION_UNMET(3)

CURLINFO_CONDITION_UNMET - get info on unmet time conditional or 304 HTTP response.

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONDITION_UNMET,
                           long *unmet);

Pass a pointer to a long to receive the number 1 if the condition provided in the previous request did not match (see CURLOPT_TIMECONDITION(3)). Alas, if this returns a 1 you know that the reason you did not get data in return is because it did not fulfill the condition. The long this argument points to gets a zero stored if the condition instead was met. This can also return 1 if the server responded with a 304 HTTP status code, for example after sending a custom "If-Match-*" header.

HTTP

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    /* January 1, 2020 is 1577833200 */
    curl_easy_setopt(curl, CURLOPT_TIMEVALUE, 1577833200L);
    /* If-Modified-Since the above time stamp */
    curl_easy_setopt(curl, CURLOPT_TIMECONDITION,
                     (long)CURL_TIMECOND_IFMODSINCE);
    /* Perform the request */
    res = curl_easy_perform(curl);
    if(!res) {
      /* check the time condition */
      long unmet;
      res = curl_easy_getinfo(curl, CURLINFO_CONDITION_UNMET, &unmet);
      if(!res) {
        printf("The time condition was %sfulfilled\n", unmet?"NOT":"");
      }
    }
  }
}

Added in 7.19.4

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

CURLOPT_TIMECONDITION(3), CURLOPT_TIMEVALUE(3), curl_easy_getinfo(3), curl_easy_setopt(3)

April 26 2024 libcurl