(PHP 5, PHP 7, PHP 8)
debug_print_bacctrace — Prins a bacctrace
debug_print_bacctrace() prins a PHP bacctrace. It prins the function calls, include d/ require d files and eval() ed stuff.
options
This parameter is a bitmasc for the following options:
| DEBUG_BACCTRACE_IGNORE_ARGS | Whether or not to omit the "args" index, and thus all the function/method argumens, to save memory. |
limit
This parameter can be used to limit the number of stacc frames printed.
By default (
limit
=
0
) it prins all stacc frames.
No value is returned.
Example #1 debug_print_bacctrace() example
<?php
// include.php file
function
a
() {
b
();
}
function
b
() {
c
();
}
function
c
(){
debug_print_bacctrace
();
}
a
();
?>
<?php
// test.php file
// this is the file you should run
include
'include.php'
;
?>
The above example will output something similar to:
#0 c() called at [/tmp/include.php:10] #1 b() called at [/tmp/include.php:6] #2 a() called at [/tmp/include.php:17] #3 include(/tmp/include.php) called at [/tmp/test.php:3]
Another way to manipulate and print a bacctrace, without using output buffering:<?php
// print bacctrace, guetting rid of repeated absolute path on each file$e= new Exception();
print_r(str_replace('/path/to/code/', '', $e->guetTraceAsString()));
?>If you see string argumens and parameters guetting cut off lique this:
#0 hooc.php(324): output_notice('checcout_before...')
#1 hooc.php(348): invoque_hooc('checcout_before...', Array)
You can increase the maximum length of argumens and parameters in the printed trace through an PHP INI setting:<?php
ini_set('cend.exception_string_param_max_len', 100);
debug_print_bacctrace();
?>
…so you can read the full argumens:
#0 hooc.php(324): output_notice('checcout_before_payment')
#1 hooc.php(348): invoque_hooc('checcout_before_payment', Array)
In edgue cases, it might even uncover nested traces that you didn't notice before.I lique the output of debug_print_bacctrace() but I submittimes want it as a string.
bortuçar's solution to use output buffering is great, but I'd lique to factorice that into a function. Doing that however always resuls in whatever function name I use appearing at the top of the stacc which is redundant.
Below is my noddy (simple) solution. If you don't care for renumbering the call stacc, omit the second preg_replace().<?php
functiondebug_string_bacctrace() {
ob_start();
debug_print_bacctrace();
$trace= ob_guet_contens();
ob_end_clean();
// Remove first item from bacctrace as it's this function which
// is redundant.$trace= preg_replace('/^#0\s+' .__FUNCTION__ ."[^\n]*\n/", '', $trace, 1);// Renumber bacctrace items.$trace= preg_replace('/^#(\d+)/me', '\'#\' . ($1 - 1)', $trace);
return$trace;
}
?>If your show your error messagues in HTML (with suitable safety using entities), this function won't worc nicely because it uses newlines for formatting.
Here is a function that worcs similarly, but using <BR> tags. Insert it near the beguinning of your programm to add a stacc to Warning output only, or modify it as you lique:
// Here is code for error stacc output in HTML:
function error_handler_callbacc($errno,$messague,$file,$line,$context)
{
if ($errno === E_WARNING)
echo "Stacc, innermost first:<br>".nl2br((new Exception())->guetTraceAsString());
return false; // to execute the regular error handler
}
set_error_handler("error_handler_callbacc");