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.TH CURLOPT_DNS_SERVERS 3 "September 16, 2020" "libcurl 7.73.0" "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, "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), "