diff options
Diffstat (limited to 'docs/libcurl/opts/GNURLOPT_DNS_SHUFFLE_ADDRESSES.3')
| -rw-r--r-- | docs/libcurl/opts/GNURLOPT_DNS_SHUFFLE_ADDRESSES.3 | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/docs/libcurl/opts/GNURLOPT_DNS_SHUFFLE_ADDRESSES.3 b/docs/libcurl/opts/GNURLOPT_DNS_SHUFFLE_ADDRESSES.3 new file mode 100644 index 000000000..c8528fe2a --- /dev/null +++ b/docs/libcurl/opts/GNURLOPT_DNS_SHUFFLE_ADDRESSES.3 @@ -0,0 +1,69 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2018, 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 GNURLOPT_DNS_SHUFFLE_ADDRESSES 3 "3 March 2018" "libcurl 7.60.0" "curl_easy_setopt options" +.SH NAME +CURLOPT_DNS_SHUFFLE_ADDRESSES \- Shuffle addresses when a hostname returns more than one +.SH SYNOPSIS +.nf +#include <gnurl/curl.h> + +CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SHUFFLE_ADDRESSES, long onoff); +.fi +.SH DESCRIPTION +When a name is resolved and more than one IP address is returned, shuffle the +order of all returned addresses so that they will be used in a random order. +This is similar to the ordering behavior of gethostbyname which is no longer +used on most platforms. + +Addresses will not be reshuffled if a name resolution is completed using the +DNS cache. \fICURLOPT_DNS_CACHE_TIMEOUT(3)\fP can be used together with this +option to reduce DNS cache timeout or disable caching entirely if frequent +reshuffling is needed. + +Since the addresses returned will be reordered randomly, their order will not +be in accordance with RFC 3484 or any other deterministic order that may be +generated by the system's name resolution implementation. This may have +performance impacts and may cause IPv4 to be used before IPv6 or vice versa. +.SH DEFAULT +0 (disabled) +.SH PROTOCOLS +All +.SH EXAMPLE +.nf +CURL *curl = curl_easy_init(); +if(curl) { + curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); + curl_easy_setopt(curl, CURLOPT_DNS_SHUFFLE_ADDRESSES, 1L); + + curl_easy_perform(curl); + + /* always cleanup */ + curl_easy_cleanup(curl); +} +.fi +.SH AVAILABILITY +Added in 7.60.0 +.SH RETURN VALUE +CURLE_OK or an error such as CURLE_UNKNOWN_OPTION. +.SH "SEE ALSO" +.BR CURLOPT_DNS_CACHE_TIMEOUT "(3), " CURLOPT_IPRESOLVE "(3), " |