debug_backtrace

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

    debug_backtrace — Генерирует обратную трассировку вызовов функций

    Описание

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

    Функция debug_backtrace() генерирует обратный стек вызовов PHP-функций.

    Список параметров

    options

    Параметр принимает битовую маску из следующих опций:

    Опции функции debug_backtrace()
    DEBUG_BACKTRACE_PROVIDE_OBJECT Опция устанавливает бит, который определяет, заполнять ли ключ "object" в выходном массиве.
    DEBUG_BACKTRACE_IGNORE_ARGS Опция устанавливает бит, который определяет, исключать ли ключ "args" из выходного массива и вместе с ним аргументы функций и методов, чтобы уменьшить расход памяти.

    Замечание:

    Объединение опций даёт четыре возможные комбинации:

    Комбинации опций функции debug_backtrace()
    debug_backtrace() Заполняются оба ключа.
    debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT)
    debug_backtrace(1)
    debug_backtrace(0) Не включается ключ "object" и заполняется ключ "args".
    debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS) Опускается ключ "object" и ключ "args".
    debug_backtrace(2)
    debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT|DEBUG_BACKTRACE_IGNORE_ARGS) Заполняется ключ "object" и опускается ключ "args".
    debug_backtrace(3)

    limit

    Параметр ограничивает количество кадров стека в выходном массиве. Со значением по умолчанию — limit=0 — возвращается весь стек вызовов функций.

    Возвращаемые значения

    Функция возвращает массив вложенных ассоциативных массивов (array). Следующая таблица приводит список возможных элементов выходного массива:

    Возможные элементы массивов в результатах функции debug_backtrace()
    Имя Тип Описание
    function string Название текущей функции. Смотрите также описание константы __FUNCTION__.
    line int Текущий номер строки. Смотрите также описание константы __LINE__.
    file string Название текущего файла. Смотрите также описание константы __FILE__.
    class string Название текущего класса. Смотрите также описание константы __CLASS__.
    object object Текущий объект.
    type string Текущий тип вызова функции. При вызове метода объекта функция возвращает значение "->". При вызове статического метода класса возвращается "::". При вызове функции ничего не возвращается.
    args array При вызове этой функции внутри другой функции элементы с этим ключом содержат списки аргументов функций. При вызове внутри включаемого файла элемент содержит названия включённых файлов.

    Примеры

    Пример #1 Пример генерации обратной трассировки вызовов функцией debug_backtrace()

    <?php

    // Файл: /tmp/a.php
    function a_test($str)
    {
    echo     "\nПривет, $str";
    var_dump(debug_backtrace());
    }

    a_test('друг');

    ?>

    <?php

    // Файл: /tmp/b.php
    include_once '/tmp/a.php';

    ?>

    При выполнении файла /tmp/b.php PHP выведет результат наподобие такого: 

    Привет, друг
array(2) {
[0]=>
array(4) {
    ["file"] => string(10) "/tmp/a.php"
    ["line"] => int(10)
    ["function"] => string(6) "a_test"
    ["args"]=>
    array(1) {
      [0] => &string(8) "друг"
    }
}
[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"
  }
}

    Смотрите также

    • trigger_error() - Генерирует предупреждение, уведомление или сообщение об ошибке на уровне пользователя
    • debug_print_backtrace() - Выводит обратную трассировку вызовов функций

    Нашли ошибку?

    Инструкция • Исправление • Сообщение об ошибке
    ＋Добавить

    Примечания пользователей 37 notes

    up
    115
    jurchiks101 at gmail dot com
    12 years ago
    Here's a function I just wrote for getting a nice and comprehensible call trace. It is probably more resource-intensive than some other alternatives but it is short, understandable, and gives nice output (Exception->getTraceAsString()).

    <?php
    function generateCallTrace()
    {
    $e = new Exception();
    $trace = explode("\n", $e->getTraceAsString());
    // reverse array to make steps line up chronologically
    $trace = array_reverse($trace);
    array_shift($trace); // remove {main}
    array_pop($trace); // remove call to this method
    $length = count($trace);
    $result = array();

    for (    $i = 0; $i < $length; $i++)
    {
    $result[] = ($i + 1) . ')' . substr($trace[$i], strpos($trace[$i], ' ')); // replace '#someNum' with '$i)', set the right ordering
    }

    return     "\t" . implode("\n\t", $result);
    }
    ?>

    Example output:
    1) /var/www/test/test.php(15): SomeClass->__construct()
    2) /var/www/test/SomeClass.class.php(36): SomeClass->callSomething()
    up
    3
    bernyregeling AT hotmail DOT com
    22 years ago
    I wrote this function, in addition to jlim, for a nice NO-HTML output.

    Thee result has similarities to a Java-error. Hope you like it.

    (BTW, this function exits the script too, if debug_backtrace is displayed)
    ------------------------------
    function debug_bt()
    {
    if(!function_exists('debug_backtrace'))
    {
    echo 'function debug_backtrace does not exists'."\r\n";
    return;
    }
    //echo '<pre>';
    echo "\r\n".'----------------'."\r\n";
    echo 'Debug backtrace:'."\r\n";
    echo '----------------'."\r\n";
    foreach(debug_backtrace() as $t)
    {
    echo "\t" . '@ ';
    if(isset($t['file'])) echo basename($t['file']) . ':' . $t['line'];
    else
    {
    // if file was not set, I assumed the functioncall
    // was from PHP compiled source (ie XML-callbacks).
    echo '<PHP inner-code>';
    }

    echo ' -- ';

    if(isset($t['class'])) echo $t['class'] . $t['type'];

    echo $t['function'];

    if(isset($t['args']) && sizeof($t['args']) > 0) echo '(...)';
    else echo '()';

    echo "\r\n";
    }
    //echo '</pre>';
    exit;
    }
    up
    13
    robert at medianis dot net
    9 years ago
    Just a short note on debug_backtrace options for PHP 5.3.6 or newer:

    debug_backtrace() - show all options
    debug_backtrace(0) - exlude ["object"]
    debug_backtrace(1) - same as debug_backtrace()
    debug_backtrace(2) - exlude ["object"] AND ["args"]

    use this example and try calling debug_backtrace with different options

    <?php
    function F1()
    {
    echo     "<br />";
    echo     "in F1 now";
    echo     "<pre>".print_r(debug_backtrace(2),true)."</pre>";
    }

    class     DebugOptionsTest
    {
    function     F2()
    {
    echo     "<br />";
    echo     "in F2 now";
    F1();
    }

    }

    echo     "<hr />calling F1";
    F1();

    $c=new DebugOptionsTest();
    echo     "<hr /><hr /><hr />calling F2";
    $c->F2("testValue");

    ?>
    up
    11
    jsnell at e-normous dot com
    18 years ago
    If you are using the backtrace function in an error handler, avoid using var_export() on the args, as you will cause fatal errors in some situations, preventing you from seeing your stack trace. Some structures will cause PHP to generate the fatal error "Nesting level too deep - recursive dependency?" This is a design feature of php, not a bug (see http://bugs.php.net/bug.php?id=30471)
    up
    2
    liam at N0SPAM dot boxclever dot ca
    2 years ago
    Options provided by bitmask parameters can be disabled using !

    <?php
    debug_backtrace    ( !DEBUG_BACKTRACE_PROVIDE_OBJECT | DEBUG_BACKTRACE_IGNORE_ARGS);
    ?>
    up
    7
    Emmett Brosnan
    9 years ago
    Quick and dirty formatted output from debug_backtrace.

    $file_paths = debug_backtrace();

    foreach($file_paths AS $file_path) {
    foreach($file_path AS $key => $var) {
    if($key == 'args') {
    foreach($var AS $key_arg => $var_arg) {
    echo $key_arg . ': ' . $var_arg . '<br>';
    }
    } else {
    echo $key . ': ' . $var . '<br>';
    }
    }
    }
    up
    4
    root at jackyyf dot com
    12 years ago
    When use register_shutdown_function, and the function called when shutting down, there are no line number nor filename information about this function, only function, class(if possible), type(if possible) and args are provided.
    up
    2
    michael dot schramm at gmail dot com
    16 years ago
    Be carefull if you are using objects as arguments for function calls!

    <?php
    error_reporting    (E_ALL);

    function     myPrint($trace){
    foreach(    $trace as $i=>$call){
    /**
    * THIS IS NEEDED! If all your objects have a __toString function it's not needed!
    *
    * Catchable fatal error: Object of class B could not be converted to string
    * Catchable fatal error: Object of class A could not be converted to string
    * Catchable fatal error: Object of class B could not be converted to string
    */
    if (is_object($call['object'])) { $call['object'] = 'CONVERTED OBJECT OF CLASS '.get_class($call['object']); }
    if (    is_array($call['args'])) {
    foreach (    $call['args'] AS &$arg) {
    if (    is_object($arg)) { $arg = 'CONVERTED OBJECT OF CLASS '.get_class($arg); }
    }
    }

    $trace_text[$i] = "#".$i." ".$call['file'].'('.$call['line'].') ';
    $trace_text[$i].= (!empty($call['object'])?$call['object'].$call['type']:'');
    $trace_text[$i].= $call['function'].'('.implode(', ',$call['args']).')';
    }

    var_dump($trace_text);
    }

    class     A{
    public function     test($obj){
    $obj->test();
    }
    }

    class     B{
    public function     test(){
    echo     myPrint(debug_backtrace());
    }
    }

    $A = new A();
    $B = new B();

    $A->test($B);

    ?>
    up
    2
    http://synergy8.com
    19 years ago
    It should be noted that if an internal php function such as call_user_func in the backtrace, the 'file' and 'line' entries will not be set.

    Most debug tracers will use these entries. You should place a check to see if the key exists in the array before using this function. Otherwise notices will be generated.

    <?php

    $arrTrace     = debug_backtrace();

    foreach (    $arrTrace as $arr)
    {
    if (!isset (    $arr['file']))
    {
    $arr['file'] = '[PHP Kernel]';
    }

    if (!isset (    $arr['line']))
    {
    $arr['line'] = '';
    }

    // Do something
    }

    ?>
    up
    3
    Bill Getas
    14 years ago
    Here's my little updated contribution - it prints colorful output in the way I prefer. Define a helper function isRootIp() that contains an array including your IP; then calls to bt() simply return, so you can sprinkle backtraces in live sites w/o anyone knowing.

    <?php
    function bt()
    {
    if( !     isRootIp() )
    {
    return     false;
    }
    array_walk( debug_backtrace(), create_function( '$a,$b', 'print "<br /><b>". basename( $a[\'file\'] ). "</b> &nbsp; <font color=\"red\">{$a[\'line\']}</font> &nbsp; <font color=\"green\">{$a[\'function\']} ()</font> &nbsp; -- ". dirname( $a[\'file\'] ). "/";' ) );
    }
    ?>
    up
    6
    Anonymous
    12 years ago
    Simple function to get a string in form "filename: [class->][function(): ]"

    <?php
    function get_caller_info() {
    $c = '';
    $file = '';
    $func = '';
    $class = '';
    $trace = debug_backtrace();
    if (isset(    $trace[2])) {
    $file = $trace[1]['file'];
    $func = $trace[2]['function'];
    if ((    substr($func, 0, 7) == 'include') || (substr($func, 0, 7) == 'require')) {
    $func = '';
    }
    } else if (isset(    $trace[1])) {
    $file = $trace[1]['file'];
    $func = '';
    }
    if (isset(    $trace[3]['class'])) {
    $class = $trace[3]['class'];
    $func = $trace[3]['function'];
    $file = $trace[2]['file'];
    } else if (isset(    $trace[2]['class'])) {
    $class = $trace[2]['class'];
    $func = $trace[2]['function'];
    $file = $trace[1]['file'];
    }
    if (    $file != '') $file = basename($file);
    $c = $file . ": ";
    $c .= ($class != '') ? ":" . $class . "->" : "";
    $c .= ($func != '') ? $func . "(): " : "";
    return(    $c);
    }
    ?>

    Usage like:

    <?php
    function debug($str) {
    echo     get_caller_info() . $str . "<br>\n";
    }
    ?>

    get_caller_info() will return info about the function /class->method that called debug().
    up
    6
    d at rren dot me
    13 years ago
    Howdy guys, just a note really - The ['args'] data within the resulting array is supplied by reference. I found myself editing the reference unknowingly which in turn shows its ugly head further down the line if you call multiple backtrace.

    <?php
    $trace     = array_reverse(debug_backtrace());

    // LOOP BACKTRACE
    $la = 0;
    $lb = count($trace);
    while (    $la<$lb){

    // DATA FROM BACKTRACE
    $trace[$la]['file'];
    $trace[$la]['line'];
    $trace[$la]['args'];
    $trace[$la]['function'];
    // DATA FROM BACKTRACE

    // LOOP ARGUMENTS ARRAY
    $ba = 0;
    $bb = count($trace[$la]['args']);
    while (    $ba<$bb){

    $trace[$la]['args'][$ba] = "EDITING A REFERENCE/POINTER";

    $ba++;
    }
    unset(    $bb);
    unset(    $ba);
    // LOOP ARGUMENTS ARRAY

    $la++;
    }
    unset(    $lb);
    unset(    $la);
    // LOOP BACKTRACE
    ?>
    up
    3
    jonas at faceways dot se
    12 years ago
    When using debug_backtrace() to check if you're being accessed from another caller, please remember to ask debug_backtrace to only go as far as needed in depth and skip taking the entire debug object as return parameter:

    <?php
    if (count(debug_backtrace(FALSE, 1)) == 0)
    {
    // Do something
    }
    ?>
    up
    2
    anoam at yandex dot ru
    11 years ago
    It works a little bit different with resources in different PHP versions.

    For example:
    function foo($bar)
    {
    return debug_backtrace();
    }

    $resource = fopen(__FILE__, 'r');
    $backtrace = foo($resource);
    echo "when resource is opened: " . gettype($backtrace[0]['args'][0]) . "\n";
    fclose($resource);
    echo "when resource is closed: " . gettype($backtrace[0]['args'][0]) . "\n";

    With 5.3.10 I got:
    when resource is opened: resource
    when resource is closed: resource

    With 5.5.9:
    when resource is opened: resource
    when resource is closed: unknown type

    Be carefull.
    up
    1
    kroczu AT interia DOT pl
    18 years ago
    <?
    // useful and comfortable debug function
    // it's show memory usage and time flow between calls, so we can quickly find a block of code that need optimisation...
    // example result:
    /*
    debug example.php> initialize
    debug example.php> code-lines: 39-41 time: 2.0002 mem: 19 KB
    debug example.php> code-lines: 41-44 time: 0.0000 mem: 19 KB
    debug example.php> code-lines: 44-51 time: 0.6343 mem: 9117 KB
    debug example.php> code-lines: 51-53 time: 0.1003 mem: 9117 KB
    debug example.php> code-lines: 53-55 time: 0.0595 mem: 49 KB
    */

    function debug()
    {
    static     $start_time = NULL;
    static     $start_code_line = 0;

    $call_info = array_shift( debug_backtrace() );
    $code_line = $call_info['line'];
    $file = array_pop( explode('/', $call_info['file']));

    if(     $start_time === NULL )
    {
    print     "debug ".$file."> initialize\n";
    $start_time = time() + microtime();
    $start_code_line = $code_line;
    return     0;
    }

    printf("debug %s> code-lines: %d-%d time: %.4f mem: %d KB\n", $file, $start_code_line, $code_line, (time() + microtime() - $start_time), ceil( memory_get_usage()/1024));
    $start_time = time() + microtime();
    $start_code_line = $code_line;
    }

    ////////////////////////////////////////////////
    // example:

    debug();
    sleep(2);
    debug();
    // soft-code...
    $a = 3 + 5;
    debug();

    // hard-code
    for( $i=0; $i<100000; $i++)
    {
    $dummy['alamakota'.$i] = 'alamakota'.$i;
    }
    debug();
    usleep(100000);
    debug();
    unset(    $dummy);
    debug();

    ?>
    up
    1
    seaside dot ki at mac dot com
    18 years ago
    I've started creating an external debug server for PHP. A PHP app require_once's a TADebugger(), which communicates with the debug sever. Find the OS X universal binary here [PHP source sample included]:

    http://www.turingart.com/downloads/phpDebugger.zip

    Currently, TADebugger allows to post these properties back to the debug server:

    - Call backtraces
    - String messages
    - Source files, which were referenced by a backtrace call

    Note, that the binary is a early version.
    up
    1
    admin at sgssweb dot com
    19 years ago
    Surprizingly, debug_backtrace() cannot aquire arguments from the function that is used as the second or later argument of a function.

    <?php

    function a($p) {
    $backtrace = debug_backtrace();

    if (isset(    $backtrace[0]['args']))
    var_export($backtrace[0]['args']);
    else
    echo     "Cannot aquire arguments";
    echo     "<br />";

    return     $p;
    }

    function     b($p1, $p2, $p3) {
    echo     "$p1, $p2, $p3";
    }

    // This outputs:
    // array ( 0 => 'First a', )
    // Cannot aquire arguments
    // Cannot aquire arguments
    // First a, Second a, Third a
    b(a("First a"), a("Second a"), a("Third a"));

    ?>
    up
    3
    jcmargentina at gmail dot com
    6 years ago
    I want to point out that debug_backtrace() in new versions of php can detect recursion // circular references .. avoiding memory consumption.

    Example:

    <?php

    class ParentClass {
    public function     __construct()
    {
    $this->_child = new ChildClass($this);
    var_dump(debug_backtrace());
    }
    }

    class     ChildClass {
    public function     __construct(ParentClass $p)
    {
    $this->_parent = $p;
    }
    }

    $test = new ParentClass();
    ?>

    Output:

    array(1) {
    [0]=>
    array(7) {
    ["file"]=>
    string(23) "/home/jcm/testdebug.php"
    ["line"]=>
    int(18)
    ["function"]=>
    string(11) "__construct"
    ["class"]=>
    string(11) "ParentClass"
    ["object"]=>
    object(ParentClass)#1 (1) {
    ["_child"]=>
    object(ChildClass)#2 (1) {
    ["_parent"]=>
    *RECURSION*
    }
    }
    ["type"]=>
    string(2) "->"
    ["args"]=>
    array(0) {
    }
    }
    }

    Attention in the *RECURSION* hint provided
    up
    7
    kenorb at gmail dot com
    15 years ago
    One line of code to print simplest and shortest human readable backtrace:)
    <?php
    array_walk    (debug_backtrace(),create_function('$a,$b','print "{$a[\'function\']}()(".basename($a[\'file\']).":{$a[\'line\']}); ";'));
    ?>
    up
    1
    jake at qzdesign dot co dot uk
    6 years ago
    The `args` element contains only the arguments actually passed to the function or method. It does not include default parameters if they were not explicitly specified. (A least, this is the case with PHP 7.1.9.) This is consistent with the behaviour of `func_get_args()`.
    up
    2
    Anonymous
    12 years ago
    A usual entry looks like this:
    <?php
    array(6) {
    'file' =>
    string(87) "DbSelector.php"
    'line'     =>
    int(171)
    'function' =>
    string(5) "error"
    'class'     =>
    string(42) "LoggingService"
    'type'     =>
    string(2) "::"
    'args'     =>
    array(    1) {
    [    0] =>
    string(27) "Connecting to DB: unittests"
    }
    }
    ?>

    Be warned though that 'file' and 'class' do not reference the same thing!
    'file' means which file calls the next step.
    'class' is the next step being called.

    So 'file' is the caller, 'class' is the callee.
    up
    1
    jlammertink at gmail dot com
    15 years ago
    I use this simple but effective function so i can see which method in the child class called the current method (in the parent class).

    <?php
    function get_caller_method()
    {
    $traces = debug_backtrace();

    if (isset(    $traces[2]))
    {
    return     $traces[2]['function'];
    }

    return     null;
    }
    ?>
    up
    1
    Gemorroj
    12 years ago
    Another variation formatting backtrace.
    Parameter $ignore to ignore the extra calls.
    <?php
    /**
    * Getting backtrace
    *
    * @param int $ignore ignore calls
    *
    * @return string
    */
    protected function getBacktrace($ignore = 2)
    {
    $trace = '';
    foreach (    debug_backtrace() as $k => $v) {
    if (    $k < $ignore) {
    continue;
    }

    array_walk($v['args'], function (&$item, $key) {
    $item = var_export($item, true);
    });

    $trace .= '#' . ($k - $ignore) . ' ' . $v['file'] . '(' . $v['line'] . '): ' . (isset($v['class']) ? $v['class'] . '->' : '') . $v['function'] . '(' . implode(', ', $v['args']) . ')' . "\n";
    }

    return     $trace;
    }
    ?>
    up
    1
    kexianbin at diyism dot com
    13 years ago
    need no Xdebug or dbg.so on server, return more detailed message:

    diyism_trace.php:
    <?php
    define    (TRACES_MODE, 'TEXTAREA');//'TEXTAREA' or 'FIREPHP'
    $GLOBALS['traces.pre']=array();
    function     my_array_diff($arr1, $arr2)
    {foreach (    $arr1 as $k=>$v)
    {if (    in_array($v, $arr2, true))
    {unset(    $arr1[$k]);
    }
    }
    return     $arr1;
    }
    function     my_var_export($var, $is_str=false)
    {    $rtn=preg_replace(array('/Array\s+\(/', '/\[(\d+)\] => (.*)\n/', '/\[([^\d].*)\] => (.*)\n/'), array('array (', '\1 => \'\2\''."\n", '\'\1\' => \'\2\''."\n"), substr(print_r($var, true), 0, -1));
    $rtn=strtr($rtn, array("=> 'array ('"=>'=> array ('));
    $rtn=strtr($rtn, array(")\n\n"=>")\n"));
    $rtn=strtr($rtn, array("'\n"=>"',\n", ")\n"=>"),\n"));
    $rtn=preg_replace(array('/\n +/e'), array('strtr(\'\0\', array(\' \'=>\' \'))'), $rtn);
    $rtn=strtr($rtn, array(" Object',"=>" Object'<-"));
    if (    $is_str)
    {return     $rtn;
    }
    else
    {echo     $rtn;
    }
    }
    function     tick_handler()
    {    $tmp=debug_backtrace();
    $trace=my_array_diff($tmp, $GLOBALS['traces.pre']);
    //echo '<pre>';var_export($trace);echo '</pre>';echo '<br/>'; //for debug diyism_trace.php
    $trace=array_values($trace);
    $GLOBALS['traces.pre']=$tmp;
    if (    count($trace)>0 && $trace[0]['file'].'/'.@$tmp[1]['function']!==@$GLOBALS['traces'][count($GLOBALS['traces'])-1]['key']) //filter empty array and rearrange array_values(), because some lines will trigger two tick events per line, for example: 1.last line is "some code;questmark>" 2.error_reporting(...
    {for ($i=count($trace)-1; $i>=0; --$i)
    {    $GLOBALS['traces'][]=$tmp_fb=array_merge(array('key'=>$trace[$i]['file'].'/'.@$tmp[$i+1]['function']), $trace[$i], array('function'=>strtr($trace[$i]['function'], array('tick_handler'=>'CONTINUE')), 'in_function'=>@$tmp[$i+1]['function']));
    TRACES_MODE==='FIREPHP'?fb(trace_output($tmp_fb), 'diyism_trace:'.++$GLOBALS['diyism_trace_no']):'';
    }
    }
    }
    function     trace_output($trace)
    {    $trace['in_function']=strtr(@$trace['in_function'], array('require'=>'', 'require_once'=>'', 'include'=>'', 'include_once'=>''));
    $trace['args']=$trace['args']?strtr(preg_replace(array('/\n +/'), array(''), preg_replace(array('/\n \d+ => /'), array(''), substr(my_var_export($trace['args'], true), 7, -3))), array("\r"=>'\r', "\n"=>'\n')):'';
    return     $trace['file'].($trace['in_function']?'/'.$trace['in_function'].'()':'').'/'.$trace['line'].': '.$trace['function'].'('.$trace['args'].')';
    }
    function     traces_output()
    {echo     '<textarea style="width:100%;height:300px;">';
    $GLOBALS['traces']=array_slice($GLOBALS['traces'], 2);//remove registering tick line and requiring 'diyism_trace.php' line
    foreach ($GLOBALS['traces'] as $k=>$trace)
    {echo     htmlentities($k.':'.trace_output($trace)."\n");
    }
    echo     '</textarea>';
    }
    register_tick_function('tick_handler');
    TRACES_MODE==='TEXTAREA'?register_shutdown_function('traces_output'):'';
    ?>

    test.php:
    <?php
    declare(ticks=1);
    require     'diyism_trace.php';

    a('a', array('hello'));
    1+2;
    b();
    function     a()
    {    $d=1;
    b();
    $d=2;
    }
    function     b()
    {    1+1;
    }
    ?>
    up
    2
    php noob
    15 years ago
    Surprisingly, no one has described one of the best uses of this: dumping a variable and showing the location. When debugging, especially a big and unfamiliar system, it's a pain remembering where I added those var dumps. Also, this way there is a separator between multiple dump calls.

    <?php

    function dump( $var ) {
    $result = var_export( $var, true );
    $loc = whereCalled();
    return     "\n<pre>Dump: $loc\n$result</pre>";
    }

    function     whereCalled( $level = 1 ) {
    $trace = debug_backtrace();
    $file = $trace[$level]['file'];
    $line = $trace[$level]['line'];
    $object = $trace[$level]['object'];
    if (    is_object($object)) { $object = get_class($object); }

    return     "Where called: line $line of $object \n(in $file)";
    }
    ?>

    In addition, calling 'whereCalled()' from any function will quickly identify locations that are doing something unexpected (e.g., updating a property at the wrong time). I'm new to PHP, but have used the equivalent in Perl for years.
    up
    0
    nyoung55 at that_google_mail.com
    12 years ago
    Here is a function to cleanly output the debug_backtrace to the error_log

    <?php
    /*
    * Send the output from a backtrace to the error_log
    * @param string $message Optional message that will be sent the the error_log before the backtrace
    */
    function log_trace($message = '') {
    $trace = debug_backtrace();
    if (    $message) {
    error_log($message);
    }
    $caller = array_shift($trace);
    $function_name = $caller['function'];
    error_log(sprintf('%s: Called from %s:%s', $function_name, $caller['file'], $caller['line']));
    foreach (    $trace as $entry_id => $entry) {
    $entry['file'] = $entry['file'] ? : '-';
    $entry['line'] = $entry['line'] ? : '-';
    if (empty(    $entry['class'])) {
    error_log(sprintf('%s %3s. %s() %s:%s', $function_name, $entry_id + 1, $entry['function'], $entry['file'], $entry['line']));
    } else {
    error_log(sprintf('%s %3s. %s->%s() %s:%s', $function_name, $entry_id + 1, $entry['class'], $entry['function'], $entry['file'], $entry['line']));
    }
    }
    }
    ?>
    up
    2
    php at kennel17 dot co dot uk
    18 years ago
    Further to my previous note, the 'object' element of the array can be used to get the parent object. So changing the get_class_static() function to the following will make the code behave as expected:

    <?php
    function get_class_static() {
    $bt = debug_backtrace();

    if (isset(    $bt[1]['object']))
    return     get_class($bt[1]['object']);
    else
    return     $bt[1]['class'];
    }
    ?>

    HOWEVER, it still fails when being called statically. Changing the last two lines of my previous example to

    <?php
    foo    ::printClassName();
    bar::printClassName();
    ?>

    ...still gives the same problematic result in PHP5, but in this case the 'object' property is not set, so that technique is unavailable.
    up
    0
    john dot risken at gmail dot com
    15 years ago
    Everybody seems to have their favorite use. I substitute this function for die(). It gives a message
    to the user and emails me a PrettyPrint of what went wrong. $info is set by me,
    and it does a special check in the database object.

    <?php
    // var_format

    function var_format($v) // pretty-print var_export
    {
    return (    str_replace(array("\n"," ","array"),
    array(    "<br>","&nbsp;","&nbsp;<i>array</i>"),
    var_export($v,true))."<br>");
    }
    function     myDie($info)
    {
    $mysqlerr=strpos($info,"ERROR=You have an error in your SQL syntax");
    if(    $mysqlerr>0)$info=substr($info,0,$mysqlerr)." mySql format error";
    $out="<br>MSG='$info'<br>".var_format($_REQUEST)."<br>";
    $bt=debug_backtrace();
    $sp=0;
    $trace="";
    foreach(    $bt as $k=>$v)
    {
    extract($v);
    $file=substr($file,1+strrpos($file,"/"));
    if(    $file=="db.php")continue; // the db object
    $trace.=str_repeat("&nbsp;",++$sp); //spaces(++$sp);
    $trace.="file=$file, line=$line, function=$function<br>";
    }
    $out.="<br>".backTrace();
    if(    substr($info,0,4)=="XXX ") // special errrors when db is inaccessible
    {
    $out=str_replace("<br>","\n",$out);
    $out=str_replace("&nbsp;"," ",$out);
    mail("me@example.com","Database Execution Error for user ".$REMOTE_ADDR,"$out");
    exit(    "Database Access Error. Please try again later.");
    }
    mail("me@example.com",'Error Monitor','Execution Error',$out);
    exit(    "DANG! An execution error in the program has been sent to the webmaster.
    If you don't get an email from him soon, please call him."    );
    }
    ?>

    This produces an output like this

    file=badmode.php, line=5, function=backTrace
    file=login.php, line=209, function=require
    file=midScreen.php, line=264, function=require
    file=masterindex.php, line=161, function=require
    file=production2.php, line=121, function=require
    file=index.php, line=16, function=require
    up
    0
    frank at frank dot com
    17 years ago
    Here is my simple example:
    Code printing variable of class which instatiates the printing class.

    Well, I am sure you understand when looking at the code:
    Print result is: jippii

    <?php
    class A {

    function     something() {
    $s = debug_backtrace();

    $callingObject = $s[1]['object'];
    $test = $callingObject->jip;
    print     $test;
    }

    }

    class     B {
    var     $jip;

    function     execute() {
    $a = new A();
    $this->jip = "jippii";
    $a->something();
    }

    }
    $control = new B();
    $control->execute();
    ?>
    up
    0
    samthor
    17 years ago
    Here's a way to get the arguments for an upstream function in your stack (works with class methods, static methods and non-class methods):
    <?php
    /**
    * getArgs - find arguments of upstream method
    * can be called with, e.g. "funcname", "class::staticmethod", "class->instancemethod".
    */
    function getArgs( $target, $subclass_ok = true ) {

    if(     strpos( $target, "::" ) ) {
    list(     $class, $target ) = explode( "::", $target, 2 );
    $type = "::";
    }
    else if(     strpos( $target, "->" ) ) {
    list(     $class, $target ) = explode( "->", $target, 2 );
    $type = "->";
    }
    else {
    $type = NULL;
    $class = NULL;
    }
    $class and $class = new ReflectionClass( $class );

    foreach(     debug_backtrace() as $obj ) {

    if(     $obj['function'] == $target ) {
    if(     $type and $obj['type'] == $type ) {
    $_cl = new ReflectionClass( $obj['class'] );
    if(     $_cl->getName() == $class->getName() or ( $subclass_ok and $_cl->isSubclassOf( $class ) ) ) {
    return     $obj['args'];
    }
    unset(     $_cl );
    }
    else if( !    $type ) {
    return     $obj['args'];
    }
    }

    }

    return     NULL;

    }
    ?>

    Some example usage:
    <?php
    class Foo {
    function     test() {
    $args = getArgs( "Foo->base" );
    print(     "the parameter 'v' to my call of base was: {$args[0]}\n" );
    }
    function     base( $v ) {
    $this->test();
    }
    }

    $f = new Foo();
    $f->base( 713 ); // will print.. ".. my call of base was: 713"

    ?>

    Trust me, there are some reasons for why you might want to do this :)
    up
    0
    icefragment at gmail dot com
    19 years ago
    A simple python-like backtrace. Note that I don't recurse into arrays if they are passed as arguments to functions.

    function backtrace()
    {
    $bt = debug_backtrace();

    echo("<br /><br />Backtrace (most recent call last):<br /><br />\n");
    for($i = 0; $i <= count($bt) - 1; $i++)
    {
    if(!isset($bt[$i]["file"]))
    echo("[PHP core called function]<br />");
    else
    echo("File: ".$bt[$i]["file"]."<br />");

    if(isset($bt[$i]["line"]))
    echo("&nbsp;&nbsp;&nbsp;&nbsp;line ".$bt[$i]["line"]."<br />");
    echo("&nbsp;&nbsp;&nbsp;&nbsp;function called: ".$bt[$i]["function"]);

    if($bt[$i]["args"])
    {
    echo("<br />&nbsp;&nbsp;&nbsp;&nbsp;args: ");
    for($j = 0; $j <= count($bt[$i]["args"]) - 1; $j++)
    {
    if(is_array($bt[$i]["args"][$j]))
    {
    print_r($bt[$i]["args"][$j]);
    }
    else
    echo($bt[$i]["args"][$j]);

    if($j != count($bt[$i]["args"]) - 1)
    echo(", ");
    }
    }
    echo("<br /><br />");
    }
    }
    up
    0
    zmorris at mac dot com
    19 years ago
    Hi, I got tired of using a trace( $message, __FILE__, __LINE__ ) function I made. It forced me to include the file and line params (since php doesn't have macros) so I decided to make an alternative.

    Simply call this new version using trace( 'my message' ); and it prints out a stack trace in a clearer way than the one stored in the debug_backtrace() array. It handles traces from outside of functions, traces in nested functions, and traces in included files, and also displays the function in a way that can be pasted right back into your php code for faster testing!

    NOTE - be sure to save your files with the correct line endings for the line numbers to work correctly, which for Mac OS X is unix. You can get to this option in the popup menu in the toolbar at the top of each window in BBEdit.

    <?php

    function print_var( $var )
    {
    if(     is_string( $var ) )
    return(     '"'.str_replace( array("\x00", "\x0a", "\x0d", "\x1a", "\x09"), array('\0', '\n', '\r', '\Z', '\t'), $var ).'"' );
    else if(     is_bool( $var ) )
    {
    if(     $var )
    return(     'true' );
    else
    return(     'false' );
    }
    else if(     is_array( $var ) )
    {
    $result = 'array( ';
    $comma = '';
    foreach(     $var as $key => $val )
    {
    $result .= $comma.print_var( $key ).' => '.print_var( $val );
    $comma = ', ';
    }
    $result .= ' )';
    return(     $result );
    }

    return(     var_export( $var, true ) ); // anything else, just let php try to print it
    }

    function     trace( $msg )
    {
    echo     "<pre>\n";

    //var_export( debug_backtrace() ); echo "</pre>\n"; return; // this line shows what is going on underneath

    $trace = array_reverse( debug_backtrace() );
    $indent = '';
    $func = '';

    echo     $msg."\n";

    foreach(     $trace as $val)
    {
    echo     $indent.$val['file'].' on line '.$val['line'];

    if(     $func ) echo ' in function '.$func;

    if(     $val['function'] == 'include' ||
    $val['function'] == 'require' ||
    $val['function'] == 'include_once' ||
    $val['function'] == 'require_once' )
    $func = '';
    else
    {
    $func = $val['function'].'(';

    if( isset(     $val['args'][0] ) )
    {
    $func .= ' ';
    $comma = '';
    foreach(     $val['args'] as $val )
    {
    $func .= $comma.print_var( $val );
    $comma = ', ';
    }
    $func .= ' ';
    }

    $func .= ')';
    }

    echo     "\n";

    $indent .= "\t";
    }

    echo     "</pre>\n";
    }

    trace( 'error outside function' );

    function     test( $param1, $param2, $param3, $param4 )
    {
    trace( 'error in test()' );
    }

    test( 1.1, "param2\n", array( 1 => "a\n", "b\n" => 2 ), false );

    ?>
    up
    1
    jlim#natsoft.com.my
    22 years ago
    Pretty print the backtrace(). Functions are indented based on call value, and file is linked using file:// for convenience.

    Enjoy, John Lim

    function adodb_backtrace($print=true)
    {
    $s = '';
    if (PHPVERSION() >= 4.3) {

    $MAXSTRLEN = 64;

    $s = '<pre align=left>';
    $traceArr = debug_backtrace();
    array_shift($traceArr);
    $tabs = sizeof($traceArr)-1;
    foreach ($traceArr as $arr) {
    for ($i=0; $i < $tabs; $i++) $s .= ' &nbsp; ';
    $tabs -= 1;
    $s .= '<font face="Courier New,Courier">';
    if (isset($arr['class'])) $s .= $arr['class'].'.';
    foreach($arr['args'] as $v) {
    if (is_null($v)) $args[] = 'null';
    else if (is_array($v)) $args[] = 'Array['.sizeof($v).']';
    else if (is_object($v)) $args[] = 'Object:'.get_class($v);
    else if (is_bool($v)) $args[] = $v ? 'true' : 'false';
    else {
    $v = (string) @$v;
    $str = htmlspecialchars(substr($v,0,$MAXSTRLEN));
    if (strlen($v) > $MAXSTRLEN) $str .= '...';
    $args[] = $str;
    }
    }

    $s .= $arr['function'].'('.implode(', ',$args).')';
    $s .= sprintf("</font><font color=#808080 size=-1> # line %4d,".
    " file: <a href=\"file:/%s\">%s</a></font>",
    $arr['line'],$arr['file'],$arr['file']);
    $s .= "\n";
    }
    $s .= '</pre>';
    if ($print) print $s;
    }
    return $s;
    }
    up
    -1
    spagmoid at yahoo dot NOSPAMcom
    21 years ago
    ATTN: jlim#natsoft.com.my

    Great function, but you have a few bugs.

    At the line:
    foreach($arr['args'] as $v)

    Change it to:
    $args = array();
    if(!empty($arr['args'])) foreach($arr['args'] as $v)

    And since line & file are not present in the array if calling from the error handler,

    $Line = (isset($arr['line'])? $arr['line'] : "unknown");
    $File = (isset($arr['file'])? $arr['file'] : "unknown");

    and substitute accordingly.

    Here's my version of it, alas with different formatting:
    ----------------------------------------

    function DBG_GetBacktrace()
    {
    $s = '';
    $MAXSTRLEN = 64;

    $s = '<pre align=left>';
    $traceArr = debug_backtrace();
    array_shift($traceArr);
    $tabs = sizeof($traceArr)-1;
    foreach($traceArr as $arr)
    {
    for ($i=0; $i < $tabs; $i++) $s .= ' &nbsp; ';
    $tabs -= 1;
    $s .= '<font face="Courier New,Courier">';
    if (isset($arr['class'])) $s .= $arr['class'].'.';
    $args = array();
    if(!empty($arr['args'])) foreach($arr['args'] as $v)
    {
    if (is_null($v)) $args[] = 'null';
    else if (is_array($v)) $args[] = 'Array['.sizeof($v).']';
    else if (is_object($v)) $args[] = 'Object:'.get_class($v);
    else if (is_bool($v)) $args[] = $v ? 'true' : 'false';
    else
    {
    $v = (string) @$v;
    $str = htmlspecialchars(substr($v,0,$MAXSTRLEN));
    if (strlen($v) > $MAXSTRLEN) $str .= '...';
    $args[] = "\"".$str."\"";
    }
    }
    $s .= $arr['function'].'('.implode(', ',$args).')</font>';
    $Line = (isset($arr['line'])? $arr['line'] : "unknown");
    $File = (isset($arr['file'])? $arr['file'] : "unknown");
    $s .= sprintf("<font color=#808080 size=-1> # line %4d, file: <a href=\"file:/%s\">%s</a></font>",
    $Line, $File, $File);
    $s .= "\n";
    }
    $s .= '</pre>';
    return $s;
    }
    up
    -1
    henzeberkheij at gmail dot com
    15 years ago
    I find it useful to know if a function is being called. in Java for instance you usually print a line with the functionname and arguments in the beginning of the function. I wanted to achieve the same thing in php thus i wrote the following class:

    <?php
    class Debug
    {
    private static     $calls;

    public static function     log($message = null)
    {
    if(!    is_array(self::$calls))
    self::$calls = array();

    $call = debug_backtrace(false);
    $call = (isset($call[1]))?$call[1]:$call[0];

    $call['message'] = $message;
    array_push(self::$calls, $call);
    }
    }
    ?>

    include this class before anything else
    usage: Debug::log($message); at the beginning of your function.

    write yourself a nice printout of the data;
    up
    -3
    ciprian dot stingu at gmail dot com
    13 years ago
    A function that i use for debug
    I shortened variables name and i eliminated the spaces from second function in order fit in post :(

    <?php
    define    ("LFP", './lt.log');
    function     LogTrace($Argument, $lfn = LFP, $itw = ' ')
    {
    error_log("=====\r", 3, $lfn);
    error_log("[BEGIN BACKTRACE]\r", 3, $lfn);
    $it = '';
    $Ts = array_reverse(debug_backtrace());
    foreach(    $Ts as $T)
    {
    if(    $T['function'] != 'include' && $T['function'] != 'require' && $T['function'] != 'include_once' && $T['function'] != 'require_once')
    {
    $ft = $it . '<'. basename($T['file']) . '> on line ' . $T['line'];
    if(    $T['function'] != 'LogTrace')
    {
    if(isset(    $T['class']))
    $ft .= ' in method ' . $T['class'] . $T['type'];
    else
    $ft .= ' in function ';
    $ft .= $Trace['function'] . '(';
    }
    else
    $ft .= '(';
    if(isset(    $T['args'][0]))
    {
    if(    $T['function'] != 'LogTrace')
    {
    $ct = '';
    foreach(    $T['args'] as $A)
    {
    $ft .= $ct . LogVar($A, '', $it, $itw, 0);
    $ct = $it . $itw . ',';
    }
    }
    else
    $ft .= LogVar($T['args'][0], '', $it, $itw, 0);
    }
    $ft .= $it . ")\r";
    error_log($ft, 3, $lfn);
    $it .= $itw;
    }
    }
    error_log("[END BACKTRACE]\r", 3, $lfn);
    }

    function     LogVar(&$Var, $vn, $pit, $itw, $nlvl, $m = '')
    {
    if(    $nlvl>=16) return;
    if(    $nlvl==0){$tv=serialize($Var);$tv=unserialize($tv);}
    else     $tv=&$Var;
    $it=$pit.$itw;
    for(    $i=0; $i<$nlvl;$i++) $it.='.'.$itw;
    $o='';$nl="\n";
    if(    is_array($tv))
    {
    if(    strlen($vn)>0) $o.=$it.$m.'<array> $'.$vn.' = (';
    else     $o.="\r".$it.$m.'<array> = (';
    $o.= $nl;$AK=array_keys($tv);
    foreach(    $AK as $AN) {$AV=&$tv[$AN];$o.=LogVar($AV,$AN,$pit,$itw,$nlvl+1);}
    $o.=$it.')'.$nl;
    }
    else if(    is_string($tv))
    {
    if(    strlen($vn)>0)$o.=$it.$m.'<string> $'.$vn.' = ';
    else     $o.=' '.$m.'<string> = ';
    if(    $tv===null) $o.='NULL';
    else     $o.='"'.$tv.'"';
    $o.=$nl;
    }
    else if(    is_bool($tv))
    {
    if(    strlen($vn) > 0) $o.=$it.$m.'<boolean> $'.$vn.' = ';
    else     $o.=' '.$m.'<boolean> = ';
    if(    $tv===true) $o.='TRUE';
    else     $o.='FALSE';
    $o.=$nl;
    }
    else if(    is_object($tv))
    {
    if(    strlen($vn)>0)
    {
    $o.=$pit.$itw;
    for(    $i=0;$i<$nlvl;$i++) $o.='.'.$itw;
    $o.=$m.'<'.get_class($tv).'::$'.$vn.'> = {'.$nl;
    }
    else     $o.=' '.$m.'<'.get_class($tv).'::> = {'.$nl;
    $R=new ReflectionClass($tv);
    $o.=$it.'.'.$itw.'Class methods {'.$nl;
    $CM=$R->getMethods();
    foreach(    $CM as $MN => $MV)
    {
    $o.=$it.'.'.$itw.'.'.$itw.implode(' ',Reflection::getModifierNames($MV->getModifiers())).' '.$MV->getName().'(';
    $MP=$MV->getParameters(); $ct='';
    foreach(    $MP as $MPN => $MPV)
    {
    $o.=$ct; $o.=$MPV->isOptional()?'[':'';
    if(    $MPV->isArray()) $o.='<array> ';
    else if(    $MPV->getClass()!==null) $o.='<'.$MPV->getClass()->getName().'::> ';
    $o.=$MPV->isPassedByReference()?'&':''; $o.='$'.$MPV->getName();
    if(    $MPV->isDefaultValueAvailable())
    {
    if(    $MPV->getDefaultValue()===null) $o.=' = NULL';
    else if(    $MPV->getDefaultValue()===true) $o.=' = TRUE';
    else if(    $MPV->getDefaultValue()===false) $o.=' = FALSE';
    else     $o.=' = '.$MPV->getDefaultValue();
    }
    $o.=$MPV->isOptional()?']':''; $ct=', ';
    }
    $o.=')'.$nl;
    }
    $o.=$it.'.'.$itw.'}'.$nl; $o.=$it.'.'.$itw.'Class properties {'.$nl;
    $CV=$R->getProperties();
    foreach(    $CV as $CN => $CV)
    {
    $M=implode(' ',Reflection::getModifierNames($CV->getModifiers())).' ';
    $CV->setAccessible(true);
    $o.=LogVar($CV->getValue($tv),$CV->getName(),$pit,$itw,$nlvl+2,$M);
    }
    $o.=$it.'.'.$itw.'}'.$nl; $o.=$it.'.'.$itw.'Object variables {'.$nl;
    $OVs=get_object_vars($tv);
    foreach(    $OVs as $ON => $OV) $o.=LogVar($OV,$ON,$pit,$itw,$nlvl+2);
    $o.=$it.'.'.$itw.'}'.$nl; $o.=$pit.$itw;
    for(    $i=0;$i<$nlvl;$i++) $o.='.'.$itw;
    $o.='}'.$nl;
    }
    else
    {
    if(    strlen($vn)>0) $o.=$it.$m.'<'.gettype($tv).'> $'.$vn.' = '.$tv;
    else     $o.=' '.$m.'<'.gettype($tv).'> = '.$tv;
    $o.=$nl;
    }
    return     $o;
    }
    //test
    date_default_timezone_set('Europe/Bucharest');
    $date = new DateTime('2010-01-28');
    LogTrace($date);
    ?>
    up
    -4
    aryel at iku dot com dot br
    17 years ago
    An easy function to pull all details of the debug backtrace:

    <?php
    function getDebugBacktrace($NL = "<BR>") {
    $dbgTrace = debug_backtrace();
    $dbgMsg .= $NL."Debug backtrace begin:$NL";
    foreach(    $dbgTrace as $dbgIndex => $dbgInfo) {
    $dbgMsg .= "\t at $dbgIndex ".$dbgInfo['file']." (line {$dbgInfo['line']}) -> {$dbgInfo['function']}(".join(",",$dbgInfo['args'])")$NL";
    }
    $dbgMsg .= "Debug backtrace end".$NL;
    return     $dbgMsg;
    }
    ?>

    Then you can call it anywhere you want to get a string with the debug backtrace in readable format (i.e. your error handling function)

    <?php
    $backtrace     = getDebugBacktrace();
    echo     "Fatal error! Cannot connect to database!";
    echo     $backtrace;
    ?>

    If you're running on command line, you might want to replace the line split. You can do that thru the function argument:

    <?php
    $backtrace     = getDebugBacktrace("\n");
    echo     "Error! Server is running out of foos! Dumping error backtrace";
    echo     $backtrace;
    ?>

    Hope that helps,
    Aryel
    ＋Добавить
    To Top