PHP Manual: Generates a backtrace

Description

array debug_backtrace ([ int $options = DEBUG_BACKTRACE_PROVIDE_OBJECT [, int $limit = 0 ]] )

debug_backtrace generates a PHP backtrace.

Parameters

options

As of 5.3.6, this parameter is a bitmask for the following options:

**debug_backtrace options**
DEBUG_BACKTRACE_PROVIDE_OBJECT	Whether or not to populate the "object" index.
DEBUG_BACKTRACE_IGNORE_ARGS	Whether or not to omit the "args" index, and thus all the function/method arguments, to save memory.

Before 5.3.6, the only values recognized are TRUE or FALSE, which are the same as setting or not setting the DEBUG_BACKTRACE_PROVIDE_OBJECT option respectively.

limit

As of 5.4.0, this parameter can be used to limit the number of stack frames returned. By default (limit=0) it returns all stack frames.

Return Values

Returns an array of associative arrays. The possible returned elements are as follows:

**Possible returned elements from debug_backtrace**
Name	Type	Description
function	string	The current function name. See also __FUNCTION__.
line	integer	The current line number. See also __LINE__.
file	string	The current file name. See also __FILE__.
class	string	The current class name. See also __CLASS__
object	object	The current object.
type	string	The current call type. If a method call, "->" is returned. If a static method call, "::" is returned. If a function call, nothing is returned.
args	array	If inside a function, this lists the functions arguments. If inside an included file, this lists the included file name(s).

Changelog

Version	Description
5.4.0	Added the optional parameter `limit`.
5.3.6	The parameter `provide_object` changed to `options` and additional option `DEBUG_BACKTRACE_IGNORE_ARGS` is added.
5.2.5	Added the optional parameter `provide_object`.
5.1.1	Added the current object as a possible return element.

Examples

Example #1 debug_backtrace example


<?php
// filename: /tmp/a.php

function a_test($str)
{
    echo "\nHi: $str";
    var_dump(debug_backtrace());
}

a_test('friend');
?>

<?php
// filename: /tmp/b.php
include_once '/tmp/a.php';
?>

Results similar to the following when executing /tmp/b.php:

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"
  }
}

debug_backtrace

Description

Parameters

Return Values

Changelog

Examples

See Also