CURLINFO_FILETIME(3) Library Functions Manual CURLINFO_FILETIME(3)

CURLINFO_FILETIME - get the remote time of the retrieved document

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_FILETIME, long *timep);

Pass a pointer to a long to receive the remote time of the retrieved document in number of seconds since January 1 1970 in the GMT/UTC time zone. If you get -1, it can be because of many reasons (it might be unknown, the server might hide it or the server does not support the command that tells document time etc) and the time of the document is unknown.

You must tell libcurl to collect this information before the transfer is made, by using the CURLOPT_FILETIME(3) option to curl_easy_setopt(3) or you this unconditionally gets a -1 back.

Consider using CURLINFO_FILETIME_T(3) to be able to extract dates beyond the year 2038 on systems using 32 bit longs (Windows).

FTP, HTTP and SFTP

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    /* Ask for filetime */
    curl_easy_setopt(curl, CURLOPT_FILETIME, 1L);
    res = curl_easy_perform(curl);
    if(CURLE_OK == res) {
      long filetime = 0;
      res = curl_easy_getinfo(curl, CURLINFO_FILETIME, &filetime);
      if((CURLE_OK == res) && (filetime >= 0)) {
        time_t file_time = (time_t)filetime;
        printf("filetime: %s", ctime(&file_time));
      }
    }
    /* always cleanup */
    curl_easy_cleanup(curl);
  }
}

Added in 7.5

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

CURLOPT_FILETIME(3), curl_easy_getinfo(3), curl_easy_setopt(3)

April 26 2024 libcurl