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.\" **************************************************************************
.\" * _ _ ____ _
.\" * Project ___| | | | _ \| |
.\" * / __| | | | |_) | |
.\" * | (__| |_| | _ <| |___
.\" * \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, 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 <curl/curl.h>
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, "http://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), "
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