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)
This functionality affects file, ftp and http
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);
}
}
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(3).
Added in curl 7.1
curl_easy_setopt(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).
CURLINFO_FILETIME(3), CURLOPT_TIMEVALUE(3)