(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
debug_backtrace — Generates a backtrace
debug_backtrace() generates a PHP backtrace.
optionsThis 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() options debug_backtrace()Populates both indexes debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT)debug_backtrace(1)debug_backtrace(0)Omits index "object"and populates index"args".debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS)Omits index "object"and index"args".debug_backtrace(2)debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT|DEBUG_BACKTRACE_IGNORE_ARGS)Populate index "object"and omit index"args".debug_backtrace(3)
limit
This parameter can be used to limit the number of stack frames returned.
By default (limit=0) it returns all stack frames.
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. |
| 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). |
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"
}
}