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),