PHP debug_backtrace() function

PHP Error and Logging Functions

Example

Generate PHP backtrace:

<?php
 function a($txt) {
     b("Glenn");
 }
 function b($txt) {
     c("Cleveland");
}
 function c($txt) {
     var_dump(debug_backtrace());
 }
 a("Peter");
 ?>

The output of the above code is similar to this:

Array (
     [0] => Array (
         [file] => C:\webfolder\test.php
         [line] => 6
         [function] => c
         [args] => Array (
             [0] => Cleveland
         )
     )
     [1] => Array (
         [file] => C:\webfolder\test.php
         [line] => 3
         [function] => b
         [args] => Array (
             [0] => Glenn
         )
     )
     [2] => Array (
         [file] => C:\webfolder\test.php
         [line] => 11
         [function] => a
         [args] => Array (
             [0] => Peter
         )
     )
 )

Definition and Usage

The debug_backtrace() function generates a backtrace (traceback).

This function displays the data generated by the code of the debug_backtrace() function.

Returns an associative array. The elements that may be returned are as follows:

Name Type Description
function string Current function name
line integer Current line number
file string Current file name
class string Current class name
object object Current object
type string

Current call type. Possible calls:

  • Returns: "->" - method call
  • Returns: "::" - static method call
  • Returns nothing - function call
args array If in a function, list the function parameters. If in the referenced file, list the name of the referenced file.

Syntax

debug_backtrace(options,limit);
Parameter Description
options

Optional. Specify the bitmask for the following options:

  • DEBUG_BACKTRACE_PROVIDE_OBJECT (whether to fill the index of "object")
  • DEBUG_BACKTRACE_IGNORE_ARGS (whether to ignore the index of "args", including all function/method parameters, which can save memory overhead.)
limit Optional. Limit the number of stack frames returned. The default is (limit=0), return all stack frames.

Technical Details

Return Value: None
PHP Version: 4.3+
PHP Update Log

PHP 5.4: Added optional parameters limit.

PHP 5.3.6: Parameter provide_object changed to optionsand added the optional parameter DEBUG_BACKTRACE_IGNORE_ARGS.

PHP 5.2.5: Added optional parameters provide_object.

PHP 5.1.1: Added the current object For the elements that may be returned.

PHP Error and Logging Functions