debug_backtrace

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

Generates a backtrace

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.

TRUE FALSE DEBUG_BACKTRACE_PROVIDE_OBJECT

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.

Returns:

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:

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:

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"
  }
}