Provided by: libcurl4-doc_7.58.0-2ubuntu3.24_all bug

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 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 the numerical IP address. If libcurl is built to support IPv6, ADDRESS 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.

       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.

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),