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<title>Generates a backtrace</title>
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</div><hr /><div id="function.debug-backtrace" class="refentry">
<div class="refnamediv">
<h1 class="refname">debug_backtrace</h1>
<p class="verinfo">(PHP 4 >= 4.3.0, PHP 5)</p><p class="refpurpose"><span class="refname">debug_backtrace</span> — <span class="dc-title">Generates a backtrace</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.debug-backtrace-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>debug_backtrace</strong></span>
([ <span class="methodparam"><span class="type">int</span> <code class="parameter">$options</code><span class="initializer"> = DEBUG_BACKTRACE_PROVIDE_OBJECT</span></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$limit</code><span class="initializer"> = 0</span></span>
]] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>debug_backtrace()</strong></span> generates a PHP backtrace.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.debug-backtrace-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">options</code></em></span>
<dd>
<p class="para">
As of 5.3.6, this parameter is a bitmask for the following options:
<table class="doctable table">
<caption><strong> <span class="function"><strong>debug_backtrace()</strong></span> options</strong></caption>
<tbody class="tbody">
<tr>
<td>DEBUG_BACKTRACE_PROVIDE_OBJECT</td>
<td>
Whether or not to populate the "object" index.
</td>
</tr>
<tr>
<td>DEBUG_BACKTRACE_IGNORE_ARGS</td>
<td>
Whether or not to omit the "args" index, and thus all the function/method arguments,
to save memory.
</td>
</tr>
</tbody>
</table>
Before 5.3.6, the only values recognized are <strong><code>TRUE</code></strong> or <strong><code>FALSE</code></strong>, which are the same as
setting or not setting the <strong><code>DEBUG_BACKTRACE_PROVIDE_OBJECT</code></strong> option respectively.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">limit</code></em></span>
<dd>
<p class="para">
As of 5.4.0, this parameter can be used to limit the number of stack frames returned.
By default (<em><code class="parameter">limit</code></em>=<em>0</em>) it returns all stack frames.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.debug-backtrace-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns an array of associative <span class="type"><a href="language.types.array.html" class="type array">array</a></span>s. The possible returned elements
are as follows:
</p>
<p class="para">
<table class="doctable table">
<caption><strong>Possible returned elements from <span class="function"><strong>debug_backtrace()</strong></span></strong></caption>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>function</td>
<td><span class="type"><a href="language.types.string.html" class="type string">string</a></span></td>
<td>
The current function name. See also
<a href="language.constants.predefined.html" class="link">__FUNCTION__</a>.
</td>
</tr>
<tr>
<td>line</td>
<td><span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span></td>
<td>
The current line number. See also
<a href="language.constants.predefined.html" class="link">__LINE__</a>.
</td>
</tr>
<tr>
<td>file</td>
<td><span class="type"><a href="language.types.string.html" class="type string">string</a></span></td>
<td>
The current file name. See also
<a href="language.constants.predefined.html" class="link">__FILE__</a>.
</td>
</tr>
<tr>
<td>class</td>
<td><span class="type"><a href="language.types.string.html" class="type string">string</a></span></td>
<td>
The current <a href="language.oop5.html" class="link">class</a> name. See also
<a href="language.constants.predefined.html" class="link">__CLASS__</a>
</td>
</tr>
<tr>
<td>object</td>
<td><span class="type"><a href="language.types.object.html" class="type object">object</a></span></td>
<td>
The current <a href="language.oop5.html" class="link">object</a>.
</td>
</tr>
<tr>
<td>type</td>
<td><span class="type"><a href="language.types.string.html" class="type string">string</a></span></td>
<td>
The current call type. If a method call, "->" is returned. If a static
method call, "::" is returned. If a function call, nothing is returned.
</td>
</tr>
<tr>
<td>args</td>
<td><span class="type"><a href="language.types.array.html" class="type array">array</a></span></td>
<td>
If inside a function, this lists the functions arguments. If
inside an included file, this lists the included file name(s).
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.debug-backtrace-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>5.4.0</td>
<td>
Added the optional parameter <em><code class="parameter">limit</code></em>.
</td>
</tr>
<tr>
<td>5.3.6</td>
<td>
The parameter <em><code class="parameter">provide_object</code></em> changed to <em><code class="parameter">options</code></em> and additional option
<strong><code>DEBUG_BACKTRACE_IGNORE_ARGS</code></strong> is added.
</td>
</tr>
<tr>
<td>5.2.5</td>
<td>
Added the optional parameter <em><code class="parameter">provide_object</code></em>.
</td>
</tr>
<tr>
<td>5.1.1</td>
<td>
Added the current <span class="type"><a href="language.types.object.html" class="type object">object</a></span> as a possible return element.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.debug-backtrace-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-449">
<p><strong>Example #1 <span class="function"><strong>debug_backtrace()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// filename: /tmp/a.php<br /><br /></span><span style="color: #007700">function </span><span style="color: #0000BB">a_test</span><span style="color: #007700">(</span><span style="color: #0000BB">$str</span><span style="color: #007700">)<br />{<br /> echo </span><span style="color: #DD0000">"\nHi: </span><span style="color: #0000BB">$str</span><span style="color: #DD0000">"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">debug_backtrace</span><span style="color: #007700">());<br />}<br /><br /></span><span style="color: #0000BB">a_test</span><span style="color: #007700">(</span><span style="color: #DD0000">'friend'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?><br /></span><br /><span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// filename: /tmp/b.php<br /></span><span style="color: #007700">include_once </span><span style="color: #DD0000">'/tmp/a.php'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>
Results similar to the following when executing
<var class="filename">/tmp/b.php</var>:
</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Hi: friend
array(2) {
[0]=>
array(4) {
["file"] => string(10) "/tmp/a.php"
["line"] => int(10)
["function"] => string(6) "a_test"
["args"]=>
array(1) {
[0] => &string(6) "friend"
}
}
[1]=>
array(4) {
["file"] => string(10) "/tmp/b.php"
["line"] => int(2)
["args"] =>
array(1) {
[0] => string(10) "/tmp/a.php"
}
["function"] => string(12) "include_once"
}
}
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.debug-backtrace-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.trigger-error.html" class="function" rel="rdfs-seeAlso">trigger_error()</a> - Generates a user-level error/warning/notice message</span></li>
<li class="member"> <span class="function"><a href="function.debug-print-backtrace.html" class="function" rel="rdfs-seeAlso">debug_print_backtrace()</a> - Prints a backtrace</span></li>
</ul>
</p>
</div>
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