1--- 2c: Copyright (C) Daniel Stenberg, <daniel.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_TIMECONDITION 5Section: 3 6Source: libcurl 7See-also: 8 - CURLINFO_FILETIME (3) 9 - CURLOPT_TIMEVALUE (3) 10--- 11 12# NAME 13 14CURLOPT_TIMECONDITION - select condition for a time request 15 16# SYNOPSIS 17 18~~~c 19#include <curl/curl.h> 20 21CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMECONDITION, long cond); 22~~~ 23 24# DESCRIPTION 25 26Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE(3) time 27value is treated. You can set this parameter to *CURL_TIMECOND_IFMODSINCE* 28or *CURL_TIMECOND_IFUNMODSINCE*. 29 30The last modification time of a file is not always known and in such instances 31this feature has no effect even if the given time condition would not have 32been met. curl_easy_getinfo(3) with the *CURLINFO_CONDITION_UNMET* 33option can be used after a transfer to learn if a zero-byte successful 34"transfer" was due to this condition not matching. 35 36# DEFAULT 37 38CURL_TIMECOND_NONE (0) 39 40# PROTOCOLS 41 42HTTP, FTP, RTSP, and FILE 43 44# EXAMPLE 45 46~~~c 47int main(void) 48{ 49 CURL *curl = curl_easy_init(); 50 if(curl) { 51 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); 52 53 /* January 1, 2020 is 1577833200 */ 54 curl_easy_setopt(curl, CURLOPT_TIMEVALUE, 1577833200L); 55 56 /* If-Modified-Since the above time stamp */ 57 curl_easy_setopt(curl, CURLOPT_TIMECONDITION, 58 (long)CURL_TIMECOND_IFMODSINCE); 59 60 /* Perform the request */ 61 curl_easy_perform(curl); 62 } 63} 64~~~ 65 66# AVAILABILITY 67 68Always 69 70# RETURN VALUE 71 72Returns CURLE_OK 73