CURLOPT_TIMECONDITION - select condition for a time request

Added in curl 7.1

CURL_TIMECOND_NONE (0)

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.

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); } }

CURLOPT_TIMECONDITION - select condition for a time request

This functionality affects http only

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) libcurl 2025-06-16 CURLOPT_TIMECONDITION(3)

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