Provided by: libcurl4-doc_7.55.1-1ubuntu2_all bug

NAME

       CURLOPT_DNS_CACHE_TIMEOUT - set life-time for DNS cache entries

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_CACHE_TIMEOUT, long age);

DESCRIPTION

       Pass  a  long,  this sets the timeout in seconds. Name resolves will be kept in memory and
       used for this number of seconds. Set to zero to completely disable caching, or set  to  -1
       to  make  the  cached  entries remain forever. By default, libcurl caches this info for 60
       seconds.

       The name resolve functions of various  libc  implementations  don't  re-read  name  server
       information  unless  explicitly  told  so  (for example, by calling res_init(3)). This may
       cause libcurl to keep using the older server even if DHCP has updated the server info, and
       this may look like a DNS cache issue to the casual libcurl-app user.

       Note  that  DNS entries have a "TTL" property but libcurl doesn't use that. This DNS cache
       timeout is entirely speculative that a name will resolve to the same address for a certain
       small amount of time into the future.

DEFAULT

       60

PROTOCOLS

       All

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/foo.bin");

         /* only reuse addresses for a very short time */
         curl_easy_setopt(curl, CURLOPT_DNS_CACHE_TIMEOUT, 2L);

         ret = curl_easy_perform(curl);

         /* in this second request, the cache will not be used if more than
            two seconds have passed since the previous name resolve */
         ret = curl_easy_perform(curl);

         curl_easy_cleanup(curl);
       }

AVAILABILITY

       Always

RETURN VALUE

       Returns CURLE_OK

SEE ALSO

       CURLOPT_DNS_USE_GLOBAL_CACHE(3), CURLOPT_DNS_SERVERS(3),