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<body class="manpage">
<div id="header">
<h1>
libtraceevent(3) Manual Page
</h1>
<h2>NAME</h2>
<div class="sectionbody">
<p>tep_read_number_field -
   Reads a number from raw data.
</p>
</div>
</div>
<div id="content">
<div class="sect1">
<h2 id="_synopsis">SYNOPSIS</h2>
<div class="sectionbody">
<div class="verseblock">
<pre class="content"><strong>#include &lt;event-parse.h&gt;</strong>

int <strong>tep_read_number_field</strong>(struct tep_format_field *<em>field</em>, const void *<em>data</em>, unsigned long long *<em>value</em>);</pre>
<div class="attribution">
</div></div>
</div>
</div>
<div class="sect1">
<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
<div class="paragraph"><p>The <strong>tep_read_number_field()</strong> function reads the value of the <em>field</em> from the
raw <em>data</em> and stores it in the <em>value</em>. The function sets the <em>value</em> according
to the endianness of the raw data and the current machine and stores it in
<em>value</em>.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_return_value">RETURN VALUE</h2>
<div class="sectionbody">
<div class="paragraph"><p>The <strong>tep_read_number_field()</strong> function retunrs 0 in case of success, or -1 in
case of an error.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_example">EXAMPLE</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000080">#include</span></span> <span style="color: #FF0000">&lt;event-parse.h&gt;</span>
<span style="color: #990000">...</span>
<span style="font-weight: bold"><span style="color: #0000FF">struct</span></span> <span style="color: #008080">tep_handle</span> <span style="color: #990000">*</span>tep <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">tep_alloc</span></span><span style="color: #990000">();</span>
<span style="color: #990000">...</span>
<span style="font-weight: bold"><span style="color: #0000FF">struct</span></span> <span style="color: #008080">tep_event</span> <span style="color: #990000">*</span>event <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">tep_find_event_by_name</span></span><span style="color: #990000">(</span>tep<span style="color: #990000">,</span> <span style="color: #FF0000">"timer"</span><span style="color: #990000">,</span> <span style="color: #FF0000">"hrtimer_start"</span><span style="color: #990000">);</span>
<span style="color: #990000">...</span>
<span style="color: #009900">void</span> <span style="font-weight: bold"><span style="color: #000000">process_record</span></span><span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">struct</span></span> <span style="color: #008080">tep_record</span> <span style="color: #990000">*</span>record<span style="color: #990000">)</span>
<span style="color: #FF0000">{</span>
        <span style="color: #009900">unsigned</span> <span style="color: #009900">long</span> <span style="color: #009900">long</span> pid<span style="color: #990000">;</span>
        <span style="font-weight: bold"><span style="color: #0000FF">struct</span></span> <span style="color: #008080">tep_format_field</span> <span style="color: #990000">*</span>field_pid <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">tep_find_common_field</span></span><span style="color: #990000">(</span>event<span style="color: #990000">,</span> <span style="color: #FF0000">"common_pid"</span><span style="color: #990000">);</span>

        <span style="font-weight: bold"><span style="color: #0000FF">if</span></span> <span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #000000">tep_read_number_field</span></span><span style="color: #990000">(</span>field_pid<span style="color: #990000">,</span> record<span style="color: #990000">-&gt;</span>data<span style="color: #990000">,</span> <span style="color: #990000">&amp;</span>pid<span style="color: #990000">)</span> <span style="color: #990000">!=</span> <span style="color: #993399">0</span><span style="color: #990000">)</span> <span style="color: #FF0000">{</span>
                <span style="font-style: italic"><span style="color: #9A1900">/* Failed to get "common_pid" value */</span></span>
        <span style="color: #FF0000">}</span>
<span style="color: #FF0000">}</span>
<span style="color: #990000">...</span></tt></pre></div></div>
</div>
</div>
<div class="sect1">
<h2 id="_files">FILES</h2>
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<pre class="content"><strong>event-parse.h</strong>
        Header file to include in order to have access to the library APIs.
<strong>-ltraceevent</strong>
        Linker switch to add when building a program that uses the library.</pre>
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<h2 id="_see_also">SEE ALSO</h2>
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<div class="paragraph"><p><strong>libtraceevent</strong>(3), <strong>trace-cmd</strong>(1)</p></div>
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<h2 id="_author">AUTHOR</h2>
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<pre class="content"><strong>Steven Rostedt</strong> &lt;<a href="mailto:rostedt@goodmis.org">rostedt@goodmis.org</a>&gt;, author of <strong>libtraceevent</strong>.
<strong>Tzvetomir Stoyanov</strong> &lt;<a href="mailto:tz.stoyanov@gmail.com">tz.stoyanov@gmail.com</a>&gt;, author of this man page.</pre>
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<h2 id="_reporting_bugs">REPORTING BUGS</h2>
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<div class="paragraph"><p>Report bugs to  &lt;<a href="mailto:linux-trace-devel@vger.kernel.org">linux-trace-devel@vger.kernel.org</a>&gt;</p></div>
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<h2 id="_license">LICENSE</h2>
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<div class="paragraph"><p>libtraceevent is Free Software licensed under the GNU LGPL 2.1</p></div>
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<h2 id="_resources">RESOURCES</h2>
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<div class="paragraph"><p><a href="https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/">https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/</a></p></div>
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Last updated
 2024-10-11 21:26:45 UTC
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