.\" ************************************************************************** .\" * _ _ ____ _ .\" * Project ___| | | | _ \| | .\" * / __| | | | |_) | | .\" * | (__| |_| | _ <| |___ .\" * \___|\___/|_| \_\_____| .\" * .\" * Copyright (C) 1998 - 2017, Daniel Stenberg, , et al. .\" * .\" * This software is licensed as described in the file COPYING, which .\" * you should have received as part of this distribution. The terms .\" * are also available at https://curl.haxx.se/docs/copyright.html. .\" * .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell .\" * copies of the Software, and permit persons to whom the Software is .\" * furnished to do so, under the terms of the COPYING file. .\" * .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY .\" * KIND, either express or implied. .\" * .\" ************************************************************************** .\" .TH CURLOPT_DNS_SERVERS 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options" .SH NAME CURLOPT_DNS_SERVERS \- set preferred DNS servers .SH SYNOPSIS #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SERVERS, char *servers); .SH DESCRIPTION Pass a char * that is the list of DNS servers to be used instead of the system default. The format of the dns servers option is: host[:port][,host[:port]]... For example: 192.168.1.100,192.168.1.101,3.4.5.6 The application does not have to keep the string around after setting this option. .SH DEFAULT NULL - use system default .SH PROTOCOLS All .SH EXAMPLE .nf CURL *curl = curl_easy_init(); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin"); curl_easy_setopt(curl, CURLOPT_DNS_SERVERS, "192.168.1.100:53,192.168.1.101"); ret = curl_easy_perform(curl); curl_easy_cleanup(curl); } .fi .SH AVAILABILITY This option requires that libcurl was built with a resolver backend that supports this operation. The c-ares backend is the only such one. Added in 7.24.0 .SH RETURN VALUE Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, CURLE_NOT_BUILT_IN if support was disabled at compile-time, CURLE_BAD_FUNCTION_ARGUMENT when given an invalid server list, or CURLE_OUT_OF_MEMORY if there was insufficient heap space. .SH "SEE ALSO" .BR CURLOPT_DNS_LOCAL_IP4 "(3), " CURLOPT_DNS_CACHE_TIMEOUT "(3), "