curl/docs/libcurl/opts/CURLINFO_CONDITION_UNMET.md

c	SPDX-License-Identifier	Title	Section	Source	See-also	Protocol	Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	CURLINFO_CONDITION_UNMET	3	libcurl	CURLOPT_TIMECONDITION (3) CURLOPT_TIMEVALUE (3) curl_easy_getinfo (3) curl_easy_setopt (3)	HTTP	7.19.4

NAME

CURLINFO_CONDITION_UNMET - unmet time conditional or 304 HTTP response

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONDITION_UNMET,
                           long *unmet);

DESCRIPTION

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.

%PROTOCOLS%

EXAMPLE

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, 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":"");
      }
    }
  }
}

%AVAILABILITY%

RETURN VALUE

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).