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<title>Truncate Task</title>
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<h2 id="touch">Truncate</h2>
<p><em>Since Apache Ant 1.7.1</em></p>
<h3>Description</h3>

<p>Set the length of one or more files, as the <code>truncate</code> Unix function or GNU
utility. In addition to working with a single file, this Task can also work
on <a href="../Types/resources.html">resources</a> and resource collections.</p>

<h3>Parameters</h3>
<table class="attr">
  <tr>
    <th scope="col">Attribute</th>
    <th scope="col">Description</th>
    <th scope="col">Required</th>
  </tr>
  <tr>
    <td>file</td>
    <td>The name of the file.</td>
    <td>Unless a nested resource collection element has been specified</td>
  </tr>
  <tr>
    <td>length</td>
    <td>Specifies the new file length (in bytes) to set.  The following suffixes are supported:
      <ul>
        <li><q>K</q> : Kilobytes (1024 bytes)</li>
        <li><q>M</q> : Megabytes (1024 K)</li>
        <li><q>G</q> : Gigabytes (1024 M)</li>
        <li><q>T</q> : Terabytes (1024 G)</li>
        <li><q>P</q> : Petabytes (1024 T)</li>
      </ul>
    </td>
    <td rowspan="2">At most one of these; omitting both implies <var>length</var>=<q>0</q>
    </td>
  </tr>
  <tr>
    <td>adjust</td>
    <td class="left">Specifies the number of bytes (and positive/negative direction) by which to
      adjust file lengths.  The same suffixes are supported for this attribute as for
      the <var>length</var> attribute.
    </td>
  </tr>
  <tr>
    <td>create</td>
    <td>Whether to create nonexistent files.</td>
    <td>No; default <q>true</q></td>
  </tr>
  <tr>
    <td>mkdirs</td>
    <td>Whether to create nonexistent parent directories when creating new files.</td>
    <td>No; default <q>false</q></td>
  </tr>
</table>
<h3>Parameters specified as nested elements</h3>
<h4>any resource collection</h4>

<p>You can use any number of nested resource collection elements to define the resources for this
task and refer to resources defined elsewhere.  <strong>Note</strong>: resources passed to this task
are expected to be filesystem-based.</p>

<h3>Examples</h3>

<p>Set the length of file <samp>foo</samp> to zero.</p>
<pre>&lt;truncate file="foo"/&gt;</pre>

<p>Set the length of file <samp>foo</samp> to 1 kilobyte (1024 bytes).</p>
<pre>&lt;truncate file="foo" length="1K"/&gt;</pre>

<p>Adjust the length of file <samp>foo</samp> upward by 1 kilobyte.</p>
<pre>&lt;truncate file="foo" adjust="1K"/&gt;</pre>

<p>Adjust the length of file <samp>foo</samp> downward by 1 megabyte.</p>
<pre>&lt;truncate file="foo" adjust="-1M"/&gt;</pre>

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