NAME

       CURLOPT_RESOLVE - provide custom host name to IP address resolves

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVE,
                                 struct curl_slist *hosts);

DESCRIPTION

       Pass  a  pointer to a linked list of strings with host name resolve information to use for
       requests with this handle. The linked  list  should  be  a  fully  valid  list  of  struct
       curl_slist  structs  properly  filled  in. Use curl_slist_append(3) to create the list and
       curl_slist_free_all(3) to clean up an entire list.

       Each   single   name   resolve   string   should   be    written    using    the    format
       HOST:PORT:ADDRESS[,ADDRESS]... where HOST is the name libcurl will try to resolve, PORT is
       the port number of the service where libcurl wants to connect to the HOST and  ADDRESS  is
       one  or  more numerical IP addresses. If you specify multiple ip addresses they need to be
       separated by comma. If libcurl is built to support IPv6, each of the ADDRESS  entries  can
       of course be either IPv4 or IPv6 style addressing.

       This option effectively pre-populates the DNS cache with entries for the host+port pair so
       redirects and everything that operations against  the  HOST+PORT  will  instead  use  your
       provided  ADDRESS.  Addresses  set  with CURLOPT_RESOLVE(3) will not time-out from the DNS
       cache like ordinary entries.

       If the DNS cache already have an entry for the given host+port pair, then this entry  will
       be  removed  and  a  new  entry  will  be created. This is because old entry may have have
       different addresses or be ordinary entries with time-outs.

       The provided ADDRESS set by this option will be used even if CURLOPT_IPRESOLVE(3)  is  set
       to make libcurl use another IP version.

       Remove names from the DNS cache again, to stop providing these fake resolves, by including
       a string in the linked list that uses the format  "-HOST:PORT".  The  host  name  must  be
       prefixed  with  a  dash,  and  the  host  name and port number must exactly match what was
       already added previously.

       Support for providing the ADDRESS within [brackets] was added in 7.57.0.

       Support for providing multiple IP addresses per entry was added in 7.59.0.

DEFAULT

       NULL

PROTOCOLS

       All

EXAMPLE

       CURL *curl;
       struct curl_slist *host = NULL;
       host = curl_slist_append(NULL, "example.com:80:127.0.0.1");

       curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_RESOLVE, host);
         curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");

         curl_easy_perform(curl);

         /* always cleanup */
         curl_easy_cleanup(curl);
       }

       curl_slist_free_all(host);

AVAILABILITY

       Added in 7.21.3. Removal support added in 7.42.0.

RETURN VALUE

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

SEE ALSO

       CURLOPT_IPRESOLVE(3), CURLOPT_DNS_CACHE_TIMEOUT(3), CURLOPT_CONNECT_TO(3),