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<h1 class="lined-header"><span>cowboy_static(3)</span></h1>
<h2 id="_name">Name</h2>
<p>cowboy_static - Static file handler</p>
<h2 id="_description">Description</h2>
<p>The module <code>cowboy_static</code> implements file serving capabilities using the REST semantics provided by <code>cowboy_rest</code>.</p>
<p>The static file handler is a pre-written handler coming with Cowboy. To serve files, use it in your routes.</p>
<h2 id="_options">Options</h2>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">opts</font></b>() <font color="#990000">::</font> {<font color="#FF6600">priv_file</font>, <font color="#009900">App</font>, <font color="#009900">Path</font>}
| {<font color="#FF6600">priv_file</font>, <font color="#009900">App</font>, <font color="#009900">Path</font>, <font color="#009900">Extra</font>}
| {<font color="#FF6600">file</font>, <font color="#009900">Path</font>}
| {<font color="#FF6600">file</font>, <font color="#009900">Path</font>, <font color="#009900">Extra</font>}
| {<font color="#FF6600">priv_dir</font>, <font color="#009900">App</font>, <font color="#009900">Path</font>}
| {<font color="#FF6600">priv_dir</font>, <font color="#009900">App</font>, <font color="#009900">Path</font>, <font color="#009900">Extra</font>}
| {<font color="#FF6600">dir</font>, <font color="#009900">Path</font>}
| {<font color="#FF6600">dir</font>, <font color="#009900">Path</font>, <font color="#009900">Extra</font>}
<font color="#009900">App</font> <font color="#990000">::</font> <b><font color="#000080">atom</font></b>()
<font color="#009900">Path</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>() | <b><font color="#000000">string</font></b>()
<font color="#009900">Extra</font> <font color="#990000">::</font> [<font color="#009900">Charset</font> | <font color="#009900">Etag</font> | <font color="#009900">Mimetypes</font>]
<font color="#009900">Charset</font> <font color="#990000">::</font> {<font color="#FF6600">charset</font>, <b><font color="#000000">module</font></b>(), <b><font color="#000080">function</font></b>()}
| {<font color="#FF6600">charset</font>, <b><font color="#000080">binary</font></b>()}
<font color="#009900">Etag</font> <font color="#990000">::</font> {<font color="#FF6600">etag</font>, <b><font color="#000000">module</font></b>(), <b><font color="#000080">function</font></b>()}
| {<font color="#FF6600">etag</font>, <font color="#000080">false</font>}
<font color="#009900">Mimetypes</font> <font color="#990000">::</font> {<font color="#FF6600">mimetypes</font>, <b><font color="#000000">module</font></b>(), <b><font color="#000080">function</font></b>()}
| {<font color="#FF6600">mimetypes</font>, <b><font color="#000080">binary</font></b>() | <font color="#009900">ParsedMime</font>}
<font color="#009900">ParsedMime</font> <font color="#990000">::</font> {<font color="#009900">Type</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">SubType</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">Params</font>}
<font color="#009900">Params</font> <font color="#990000">::</font> [{<font color="#009900">Key</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">Value</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()}]</tt></pre>
</div></div>
<p>Static handler configuration.</p>
<dl><dt>priv_file</dt>
<dd><p>Send a file.</p>
<p>The path is relative to the given application's private directory.</p>
</dd>
<dt>file</dt>
<dd><p>Send a file.</p>
<p>The path is either absolute or relative to the Erlang node's current directory.</p>
</dd>
<dt>priv_dir</dt>
<dd><p>Recursively serve files from a directory.</p>
<p>The path is relative to the given application's private directory.</p>
</dd>
<dt>dir</dt>
<dd><p>Recursively serve files from a directory.</p>
<p>The path is either absolute or relative to the Erlang node's current directory.</p>
</dd>
</dl>
<p>The extra options allow you to define how the etag should be calculated and how the MIME type of files should be detected.</p>
<p>By default the static handler will not send a charset with the response. You can provide a specific charset that will be used for all files using the text media type, or provide a module and function that will be called when needed:</p>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">detect_charset</font></b>(<font color="#009900">Path</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()) <font color="#990000">-></font> <font color="#009900">Charset</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()</tt></pre>
</div></div>
<p>A charset must always be returned even if it doesn't make sense considering the media type of the file. A good default is <code><<"utf-8">></code>.</p>
<p>By default the static handler will generate an etag based on the size and modification time of the file. You may disable the etag entirely with <code>{etag, false}</code> or provide a module and function that will be called when needed:</p>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">generate_etag</font></b>(<font color="#009900">Path</font>, <font color="#009900">Size</font>, <font color="#009900">Mtime</font>) <font color="#990000">-></font> {<font color="#FF6600">strong</font> | <font color="#FF6600">weak</font>, <b><font color="#000080">binary</font></b>()}
<font color="#009900">Path</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()
<font color="#009900">Size</font> <font color="#990000">::</font> <b><font color="#000000">non_neg_integer</font></b>()
<font color="#009900">Mtime</font> <font color="#990000">::</font> <b><font color="#000000">file:date_time</font></b>()</tt></pre>
</div></div>
<p>By default the static handler will detect Web-related MIME types by looking at the file extension. You can provide a specific MIME type that will always be used, or a module and function that will be called when needed:</p>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">detect_mimetype</font></b>(<font color="#009900">Path</font>) <font color="#990000">-></font> <font color="#009900">ParsedMime</font>
<font color="#009900">Path</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()
<font color="#009900">ParsedMime</font> <font color="#990000">::</font> {<font color="#009900">Type</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">SubType</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">Params</font>}
<font color="#009900">Params</font> <font color="#990000">::</font> [{<font color="#009900">Key</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>(), <font color="#009900">Value</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>()}]</tt></pre>
</div></div>
<!-- @todo Case sensitivity of parsed mime content?-->
<p>Cowboy comes with two such functions; the default function <code>cow_mimetypes:web/1</code>, and a second function generated from the Apache <em>mime.types</em> file, <code>cow_mimetypes:all/1</code>.</p>
<p>The MIME type function should return <code>{<<"application">>, <<"octet-stream">>, []}</code> when it fails to detect a file's MIME type.</p>
<h2 id="_changelog">Changelog</h2>
<ul><li><strong>2.6</strong>: The <code>charset</code> extra option was added.
</li>
<li><strong>1.0</strong>: Handler introduced.
</li>
</ul>
<h2 id="_examples">Examples</h2>
<div class="listingblock"><div class="title">Custom etag function</div>
<div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">generate_etag</font></b>(<font color="#009900">Path</font>, <font color="#009900">Size</font>, <font color="#009900">Mtime</font>) <font color="#990000">-></font>
{<font color="#FF6600">strong</font>, <b><font color="#000000">integer_to_binary</font></b>(
<b><font color="#000000">erlang:phash2</font></b>({<font color="#009900">Path</font>, <font color="#009900">Size</font>, <font color="#009900">Mtime</font>}, <font color="#993399">16#ffffffff</font>))}<font color="#990000">.</font></tt></pre>
</div></div>
<div class="listingblock"><div class="title">Custom MIME type function</div>
<div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000000">always_octet_stream</font></b>(<font color="#009900">_Path</font>) <font color="#990000">-></font>
<b><font color="#0000FF">case</font></b> <b><font color="#000000">filename:extension</font></b>(<font color="#009900">Path</font>) <b><font color="#0000FF">of</font></b>
<font color="#990000"><<</font><font color="#FF0000">".erl"</font><font color="#990000">>></font> <font color="#990000">-></font> {<font color="#990000"><<</font><font color="#FF0000">"text"</font><font color="#990000">>></font>, <font color="#990000"><<</font><font color="#FF0000">"plain"</font><font color="#990000">>></font>, []};
<font color="#990000">_</font> <font color="#990000">-></font> {<font color="#990000"><<</font><font color="#FF0000">"application"</font><font color="#990000">>></font>, <font color="#990000"><<</font><font color="#FF0000">"octet-stream"</font><font color="#990000">>></font>, []}
<b><font color="#0000FF">end</font></b><font color="#990000">.</font></tt></pre>
</div></div>
<h2 id="_see_also">See also</h2>
<p><a href="..">cowboy(7)</a>, <a href="../cowboy_router">cowboy_router(3)</a></p>
</div>
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<h3>
Cowboy
2.6
Function Reference
</h3>
<ul>
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<li><a href="/docs/en/cowboy/2.6/manual">Function Reference</a></li>
</ul>
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<h4>Version select</h4>
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<li><a href="/docs/en/cowboy/2.6/manual">2.6</a></li>
<li><a href="/docs/en/cowboy/2.5/manual">2.5</a></li>
<li><a href="/docs/en/cowboy/2.4/manual">2.4</a></li>
<li><a href="/docs/en/cowboy/2.3/manual">2.3</a></li>
<li><a href="/docs/en/cowboy/2.2/manual">2.2</a></li>
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