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debug_backtrace

PHP function Edit on GitHub ✎

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

Generates a backtrace

Description

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

debug_backtrace() generates a PHP backtrace.

Parameters

options

This parameter is a bitmask for the following 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.

Note

There are four possible combinations:

`debug_backtrace()`	Populates both indexes
`debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT)`
`debug_backtrace(~DEBUG_BACKTRACE_PROVIDE_OBJECT)`	Omits index `"object"` and populates index `"args"`.
`debug_backtrace(0)`
`debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS)`	Omits both index `"object"` and index `"args"`.
`debug_backtrace(~DEBUG_BACKTRACE_PROVIDE_OBJECT \| DEBUG_BACKTRACE_IGNORE_ARGS)`
`debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT\|DEBUG_BACKTRACE_IGNORE_ARGS)`	Populate index `"object"` and omit index `"args"`.

limit

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:

Name	Type	Description
function	`string`	The current function name. See also __FUNCTION__.
line	`int`	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 if `DEBUG_BACKTRACE_PROVIDE_OBJECT` is given.
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). Unless `DEBUG_BACKTRACE_IGNORE_ARGS` is given.

Examples

debug_backtrace() example

php

<?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:

output

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

Examples

See Also