1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3<html><head> 4<title>CURLOPT_DNS_CACHE_TIMEOUT man page</title> 5<meta name="generator" content="roffit"> 6<STYLE type="text/css"> 7P.level0 { 8 padding-left: 2em; 9} 10 11P.level1 { 12 padding-left: 4em; 13} 14 15P.level2 { 16 padding-left: 6em; 17} 18 19span.emphasis { 20 font-style: italic; 21} 22 23span.bold { 24 font-weight: bold; 25} 26 27span.manpage { 28 font-weight: bold; 29} 30 31h2.nroffsh { 32 background-color: #e0e0e0; 33} 34 35span.nroffip { 36 font-weight: bold; 37 font-size: 120%; 38 font-family: monospace; 39} 40 41p.roffit { 42 text-align: center; 43 font-size: 80%; 44} 45</STYLE> 46</head><body> 47 48<p class="level0"><a name="NAME"></a><h2 class="nroffsh">NAME</h2> 49<p class="level0">CURLOPT_DNS_CACHE_TIMEOUT - set life-time for DNS cache entries <a name="SYNOPSIS"></a><h2 class="nroffsh">SYNOPSIS</h2> 50<p class="level0">#include <curl/curl.h> 51<p class="level0">CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_CACHE_TIMEOUT, long age); <a name="DESCRIPTION"></a><h2 class="nroffsh">DESCRIPTION</h2> 52<p class="level0">Pass a long, this sets the timeout in seconds. Name resolves will be kept in memory and used for this number of seconds. Set to zero to completely disable caching, or set to -1 to make the cached entries remain forever. By default, libcurl caches this info for 60 seconds. 53<p class="level0">The name resolve functions of various libc implementations don't re-read name server information unless explicitly told so (for example, by calling <span Class="emphasis">res_init(3)</span>). This may cause libcurl to keep using the older server even if DHCP has updated the server info, and this may look like a DNS cache issue to the casual libcurl-app user. 54<p class="level0">Note that DNS entries have a "TTL" property but libcurl doesn't use that. This DNS cache timeout is entirely speculative that a name will resolve to the same address for a certain small amount of time into the future. <a name="DEFAULT"></a><h2 class="nroffsh">DEFAULT</h2> 55<p class="level0">60 <a name="PROTOCOLS"></a><h2 class="nroffsh">PROTOCOLS</h2> 56<p class="level0">All <a name="EXAMPLE"></a><h2 class="nroffsh">EXAMPLE</h2> 57<p class="level0">TODO <a name="AVAILABILITY"></a><h2 class="nroffsh">AVAILABILITY</h2> 58<p class="level0">Always <a name="RETURN"></a><h2 class="nroffsh">RETURN VALUE</h2> 59<p class="level0">Returns CURLE_OK <a name="SEE"></a><h2 class="nroffsh">SEE ALSO</h2> 60<p class="level0"><a Class="manpage" href="/CURLOPT_DNS_USE_GLOBAL_CACHE.html">CURLOPT_DNS_USE_GLOBAL_CACHE</a> <a Class="manpage" href="/CURLOPT_DNS_SERVERS.html">CURLOPT_DNS_SERVERS</a> <span Class="manpage"> </span> <p class="roffit"> 61 This HTML page was made with <a href="http://daniel.haxx.se/projects/roffit/">roffit</a>. 62</body></html> 63