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CURLOPT_RESOLVE(3)	   curl_easy_setopt options	    CURLOPT_RESOLVE(3)


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 sepa-
       rated 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 ordi-
       nary 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  CUR-
       LOPT_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	previ-
       ously.

       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_CON-
       NECT_TO(3),

libcurl 7.63.0			 May 30, 2018		    CURLOPT_RESOLVE(3)

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