curl/docs/libcurl/opts/CURLINFO_CONDITION_UNMET.md
Viktor Szakats 61df5f466c
tidy-up: miscellaneous
- curl_ntlm_core, smtp, schannel: fix comments.
- curl_setup.h: fix to undef before define.
- tool_doswin, server/sockfilt: reduce variables scopes.
- tool_doswin: drop an interim variable.
- windows: replace `SOCKET_ERROR` with `0` to align with rest of code.
- libssh2: rename variable to align with rest of code.
- gtls, unit1398: use `#if 0`.
- curl_trc.h, curlx/inet_ntop.h: add missing parentheses in macro
  expressions.
- ldap.c: set empty macro to `do {} while(0)`.
- examples/crawler: rename a non-CURLcode `result` variable.
- CURLINFO_TLS_SESSION: drop stray colon.
- add `const` to casts where missing.
- drop unnecessary parentheses.
- fix indent.
- quote style.
- comment style.
- whitespace, newlines, fold/unfold.

Closes #20554
2026-02-12 14:52:16 +01:00

2 KiB

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 result;

    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 */
    result = curl_easy_perform(curl);

    if(result == CURLE_OK) {
      /* check the time condition */
      long unmet;
      result = curl_easy_getinfo(curl, CURLINFO_CONDITION_UNMET, &unmet);
      if(result == CURLE_OK) {
        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).