curl / libcurl / API / curl_easy_setopt / CURLOPT_TIMECONDITION

CURLOPT_TIMECONDITION explained

Name

CURLOPT_TIMECONDITION - select condition for a time request

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMECONDITION, long cond);

Description

Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE time value is treated. You can set this parameter to CURL_TIMECOND_IFMODSINCE or CURL_TIMECOND_IFUNMODSINCE.

The last modification time of a file is not always known and in such instances this feature has no effect even if the given time condition would not have been met. curl_easy_getinfo with the CURLINFO_CONDITION_UNMET option can be used after a transfer to learn if a zero-byte successful "transfer" was due to this condition not matching.

Default

CURL_TIMECOND_NONE (0)

Protocols

This functionality affects file, ftp and http

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    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 */
    curl_easy_perform(curl);
  }
}

History

CURL_TIMECOND_* enums became long types in 8.13.0, prior to this version a long cast was necessary when passed to curl_easy_setopt.

Availability

Added in curl 7.1

Return value

curl_easy_setopt returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors.