CURLOPT_TIMECONDITION(3) Library Functions Manual CURLOPT_TIMECONDITION(3)

CURLOPT_TIMECONDITION - select condition for a time request

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

Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE(3) 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(3) 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.

CURL_TIMECOND_NONE (0)

HTTP, FTP, RTSP, and FILE

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,
(long)CURL_TIMECOND_IFMODSINCE);
/* Perform the request */
curl_easy_perform(curl);
} }

Always

Returns CURLE_OK

CURLINFO_FILETIME(3), CURLOPT_TIMEVALUE(3)

March 12 2024 libcurl