File: C:/Ruby27-x64/share/doc/ruby/html/Resolv.html
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<h3>Parent</h3>
<p class="link"><a href="Object.html">Object</a>
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<!-- Method Quickref -->
<div id="method-list-section" class="nav-section">
<h3>Methods</h3>
<ul class="link-list" role="directory">
<li ><a href="#method-c-each_address">::each_address</a>
<li ><a href="#method-c-each_name">::each_name</a>
<li ><a href="#method-c-getaddress">::getaddress</a>
<li ><a href="#method-c-getaddresses">::getaddresses</a>
<li ><a href="#method-c-getname">::getname</a>
<li ><a href="#method-c-getnames">::getnames</a>
<li ><a href="#method-c-new">::new</a>
<li ><a href="#method-i-each_address">#each_address</a>
<li ><a href="#method-i-each_name">#each_name</a>
<li ><a href="#method-i-getaddress">#getaddress</a>
<li ><a href="#method-i-getaddresses">#getaddresses</a>
<li ><a href="#method-i-getname">#getname</a>
<li ><a href="#method-i-getnames">#getnames</a>
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<h1 id="class-Resolv" class="class">
class Resolv
</h1>
<section class="description">
<p><a href="Resolv.html"><code>Resolv</code></a> is a thread-aware <a href="Resolv/DNS.html"><code>DNS</code></a> resolver library written in Ruby. <a href="Resolv.html"><code>Resolv</code></a> can handle multiple <a href="Resolv/DNS.html"><code>DNS</code></a> requests concurrently without blocking the entire Ruby interpreter.</p>
<p>See also resolv-replace.rb to replace the libc resolver with <a href="Resolv.html"><code>Resolv</code></a>.</p>
<p><a href="Resolv.html"><code>Resolv</code></a> can look up various <a href="Resolv/DNS.html"><code>DNS</code></a> resources using the <a href="Resolv/DNS.html"><code>DNS</code></a> module directly.</p>
<p>Examples:</p>
<pre class="ruby"><span class="ruby-identifier">p</span> <span class="ruby-constant">Resolv</span>.<span class="ruby-identifier">getaddress</span> <span class="ruby-string">"www.ruby-lang.org"</span>
<span class="ruby-identifier">p</span> <span class="ruby-constant">Resolv</span>.<span class="ruby-identifier">getname</span> <span class="ruby-string">"210.251.121.214"</span>
<span class="ruby-constant">Resolv</span><span class="ruby-operator">::</span><span class="ruby-constant">DNS</span>.<span class="ruby-identifier">open</span> <span class="ruby-keyword">do</span> <span class="ruby-operator">|</span><span class="ruby-identifier">dns</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">ress</span> = <span class="ruby-identifier">dns</span>.<span class="ruby-identifier">getresources</span> <span class="ruby-string">"www.ruby-lang.org"</span>, <span class="ruby-constant">Resolv</span><span class="ruby-operator">::</span><span class="ruby-constant">DNS</span><span class="ruby-operator">::</span><span class="ruby-constant">Resource</span><span class="ruby-operator">::</span><span class="ruby-constant">IN</span><span class="ruby-operator">::</span><span class="ruby-constant">A</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">ress</span>.<span class="ruby-identifier">map</span>(<span class="ruby-operator">&</span><span class="ruby-value">:address</span>)
<span class="ruby-identifier">ress</span> = <span class="ruby-identifier">dns</span>.<span class="ruby-identifier">getresources</span> <span class="ruby-string">"ruby-lang.org"</span>, <span class="ruby-constant">Resolv</span><span class="ruby-operator">::</span><span class="ruby-constant">DNS</span><span class="ruby-operator">::</span><span class="ruby-constant">Resource</span><span class="ruby-operator">::</span><span class="ruby-constant">IN</span><span class="ruby-operator">::</span><span class="ruby-constant">MX</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">ress</span>.<span class="ruby-identifier">map</span> { <span class="ruby-operator">|</span><span class="ruby-identifier">r</span><span class="ruby-operator">|</span> [<span class="ruby-identifier">r</span>.<span class="ruby-identifier">exchange</span>.<span class="ruby-identifier">to_s</span>, <span class="ruby-identifier">r</span>.<span class="ruby-identifier">preference</span>] }
<span class="ruby-keyword">end</span>
</pre>
<h2 id="class-Resolv-label-Bugs">Bugs<span><a href="#class-Resolv-label-Bugs">¶</a> <a href="#top">↑</a></span></h2>
<ul><li>
<p>NIS is not supported.</p>
</li><li>
<p>/etc/nsswitch.conf is not supported.</p>
</li></ul>
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section class="constants-list">
<header>
<h3>Constants</h3>
</header>
<dl>
<dt id="AddressRegex">AddressRegex
<dd><p>Address <a href="Regexp.html"><code>Regexp</code></a> to use for matching IP addresses.</p>
<dt id="DefaultResolver">DefaultResolver
<dd><p>Default resolver to use for <a href="Resolv.html"><code>Resolv</code></a> class methods.</p>
</dl>
</section>
<section id="public-class-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Class Methods</h3>
</header>
<div id="method-c-each_address" class="method-detail ">
<div class="method-heading">
<span class="method-name">each_address</span><span
class="method-args">(name, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Iterates over all IP addresses for <code>name</code>.</p>
<div class="method-source-code" id="each_address-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 57</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">each_address</span>(<span class="ruby-identifier">name</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">each_address</span>(<span class="ruby-identifier">name</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-each_name" class="method-detail ">
<div class="method-heading">
<span class="method-name">each_name</span><span
class="method-args">(address, &proc)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Iterates over all hostnames for <code>address</code>.</p>
<div class="method-source-code" id="each_name-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 78</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">each_name</span>(<span class="ruby-identifier">address</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">proc</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">each_name</span>(<span class="ruby-identifier">address</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">proc</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-getaddress" class="method-detail ">
<div class="method-heading">
<span class="method-name">getaddress</span><span
class="method-args">(name)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up the first IP address for <code>name</code>.</p>
<div class="method-source-code" id="getaddress-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 43</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">getaddress</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">getaddress</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-getaddresses" class="method-detail ">
<div class="method-heading">
<span class="method-name">getaddresses</span><span
class="method-args">(name)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up all IP address for <code>name</code>.</p>
<div class="method-source-code" id="getaddresses-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 50</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">getaddresses</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">getaddresses</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-getname" class="method-detail ">
<div class="method-heading">
<span class="method-name">getname</span><span
class="method-args">(address)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up the hostname of <code>address</code>.</p>
<div class="method-source-code" id="getname-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 64</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">getname</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">getname</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-getnames" class="method-detail ">
<div class="method-heading">
<span class="method-name">getnames</span><span
class="method-args">(address)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up all hostnames for <code>address</code>.</p>
<div class="method-source-code" id="getnames-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 71</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">getnames</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-constant">DefaultResolver</span>.<span class="ruby-identifier">getnames</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-new" class="method-detail ">
<div class="method-heading">
<span class="method-name">new</span><span
class="method-args">(resolvers=[Hosts.new, DNS.new])</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Creates a new <a href="Resolv.html"><code>Resolv</code></a> using <code>resolvers</code>.</p>
<div class="method-source-code" id="new-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 85</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">initialize</span>(<span class="ruby-identifier">resolvers</span>=[<span class="ruby-constant">Hosts</span>.<span class="ruby-identifier">new</span>, <span class="ruby-constant">DNS</span>.<span class="ruby-identifier">new</span>])
<span class="ruby-ivar">@resolvers</span> = <span class="ruby-identifier">resolvers</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
</section>
<section id="public-instance-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Instance Methods</h3>
</header>
<div id="method-i-each_address" class="method-detail ">
<div class="method-heading">
<span class="method-name">each_address</span><span
class="method-args">(name) { |name| ... }</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Iterates over all IP addresses for <code>name</code>.</p>
<div class="method-source-code" id="each_address-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 109</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">each_address</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">AddressRegex</span> <span class="ruby-operator">=~</span> <span class="ruby-identifier">name</span>
<span class="ruby-keyword">yield</span> <span class="ruby-identifier">name</span>
<span class="ruby-keyword">return</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">yielded</span> = <span class="ruby-keyword">false</span>
<span class="ruby-ivar">@resolvers</span>.<span class="ruby-identifier">each</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">r</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">r</span>.<span class="ruby-identifier">each_address</span>(<span class="ruby-identifier">name</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">address</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">yield</span> <span class="ruby-identifier">address</span>.<span class="ruby-identifier">to_s</span>
<span class="ruby-identifier">yielded</span> = <span class="ruby-keyword">true</span>
}
<span class="ruby-keyword">return</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">yielded</span>
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-each_name" class="method-detail ">
<div class="method-heading">
<span class="method-name">each_name</span><span
class="method-args">(address) { |name| ... }</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Iterates over all hostnames for <code>address</code>.</p>
<div class="method-source-code" id="each_name-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 144</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">each_name</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-identifier">yielded</span> = <span class="ruby-keyword">false</span>
<span class="ruby-ivar">@resolvers</span>.<span class="ruby-identifier">each</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">r</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">r</span>.<span class="ruby-identifier">each_name</span>(<span class="ruby-identifier">address</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">name</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">yield</span> <span class="ruby-identifier">name</span>.<span class="ruby-identifier">to_s</span>
<span class="ruby-identifier">yielded</span> = <span class="ruby-keyword">true</span>
}
<span class="ruby-keyword">return</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">yielded</span>
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-getaddress" class="method-detail ">
<div class="method-heading">
<span class="method-name">getaddress</span><span
class="method-args">(name)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up the first IP address for <code>name</code>.</p>
<div class="method-source-code" id="getaddress-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 92</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">getaddress</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-identifier">each_address</span>(<span class="ruby-identifier">name</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">address</span><span class="ruby-operator">|</span> <span class="ruby-keyword">return</span> <span class="ruby-identifier">address</span>}
<span class="ruby-identifier">raise</span> <span class="ruby-constant">ResolvError</span>.<span class="ruby-identifier">new</span>(<span class="ruby-node">"no address for #{name}"</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-getaddresses" class="method-detail ">
<div class="method-heading">
<span class="method-name">getaddresses</span><span
class="method-args">(name)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up all IP address for <code>name</code>.</p>
<div class="method-source-code" id="getaddresses-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 100</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">getaddresses</span>(<span class="ruby-identifier">name</span>)
<span class="ruby-identifier">ret</span> = []
<span class="ruby-identifier">each_address</span>(<span class="ruby-identifier">name</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">address</span><span class="ruby-operator">|</span> <span class="ruby-identifier">ret</span> <span class="ruby-operator"><<</span> <span class="ruby-identifier">address</span>}
<span class="ruby-keyword">return</span> <span class="ruby-identifier">ret</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-getname" class="method-detail ">
<div class="method-heading">
<span class="method-name">getname</span><span
class="method-args">(address)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up the hostname of <code>address</code>.</p>
<div class="method-source-code" id="getname-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 127</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">getname</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-identifier">each_name</span>(<span class="ruby-identifier">address</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">name</span><span class="ruby-operator">|</span> <span class="ruby-keyword">return</span> <span class="ruby-identifier">name</span>}
<span class="ruby-identifier">raise</span> <span class="ruby-constant">ResolvError</span>.<span class="ruby-identifier">new</span>(<span class="ruby-node">"no name for #{address}"</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-getnames" class="method-detail ">
<div class="method-heading">
<span class="method-name">getnames</span><span
class="method-args">(address)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Looks up all hostnames for <code>address</code>.</p>
<div class="method-source-code" id="getnames-source">
<pre><span class="ruby-comment"># File lib/resolv.rb, line 135</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">getnames</span>(<span class="ruby-identifier">address</span>)
<span class="ruby-identifier">ret</span> = []
<span class="ruby-identifier">each_name</span>(<span class="ruby-identifier">address</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">name</span><span class="ruby-operator">|</span> <span class="ruby-identifier">ret</span> <span class="ruby-operator"><<</span> <span class="ruby-identifier">name</span>}
<span class="ruby-keyword">return</span> <span class="ruby-identifier">ret</span>
<span class="ruby-keyword">end</span></pre>
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