debug_backtrace

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tiwen at rpgame dot de
01-May-2006 04:25


Another debug output. This is a short function that does not display the args (sometimes password are in arguments ...) and shows the callstack clearly in a table. In most cases i don't need more ...



<?php

function dieDebug($sError)

{

    echo "<hr /><div>".$sError."<br /><table border='1'>";

    $sOut=""; $aCallstack=debug_backtrace();

    

    echo "<thead><tr><th>file</th><th>line</th><th>function</th>".

        "</tr></thead>";

    foreach($aCallstack as $aCall)

    {

        if (!isset($aCall['file'])) $aCall['file'] = '[PHP Kernel]';

        if (!isset($aCall['line'])) $aCall['line'] = '';



        echo "<tr><td>{$aCall["file"]}</td><td>{$aCall["line"]}</td>".

            "<td>{$aCall["function"]}</td></tr>";

    }

    echo "</table></div><hr /></p>";

    die();

}

?>



To use it, simply do something like this:



<?php

if(...) dieDebug("another error found!");

?>

http://synergy8.com
14-Dec-2005 02:37


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

}



?>

tb
22-Jul-2005 02:18


I use this for debugging in my object oriented systems.  It allows me to output a debug/error/warning function with exact information about the location that the error was thrown, which is useful.  Check it:



<?php

abstract class Debugger {

    

    /**

     * Throw a debug message.

     */

    abstract function debug($msg);

    

    /**

     * Throw an error message.

     */

    abstract function error($msg);

    

    /**

     * Throw a warning message.

     */

    abstract function warning($msg);

    

    /**

     * Wrap a message with information about class, function, file and line

     * number and return it.

     */

    protected function getMsg($msg) {

        $bt = debug_backtrace();

        

        // get class, function called by caller of caller of caller

        $class = $bt[2]['class'];

        $function = $bt[2]['function'];

        

        // get file, line where call to caller of caller was made

        $file = $bt[1]['file'];

        $line = $bt[1]['line'];

        

        // build & return the message

        return "$class::$function: $msg in $file at $line";

    }

    

}

?>



Implement different debuggers for different scenarios (development, testing, production).  Each debugger extends Debugger; each of its methods (debug/error/warning) calls $this->getMsg($msg) to get a message with class, function, file, and line information.  Then it can either log it, email it, die with it, etc.



Then, just give each object (perhaps using a common superclass Object) a concrete debugger.  Then, from any object method, do something like:



<?php

class Foo extends Object {

     function bar() {

          $this->debugger->error("This is an error");

     }

}

?>



Which produces something like:



Foo::bar: This is an error in /some/file at X

diz at ysagoon dot com
24-Nov-2004 06:35


Ok as spagmoid already said, I just realized that my function has a similar bug than jlim's function.



So just add the following line:

if (is_array($bt['args']))

before line:

foreach ($bt['args'] as $a) {



This way you avoid the warning from being displayed.

diz at ysagoon dot com
24-Nov-2004 06:40


And here are my two cents for a useful and good looking backtrace function.



<?php



function backtrace()

{

    $output = "<div style='text-align: left; font-family: monospace;'>\n";

    $output .= "<b>Backtrace:</b><br />\n";

    $backtrace = debug_backtrace();



    foreach ($backtrace as $bt) {

        $args = '';

        foreach ($bt['args'] as $a) {

            if (!empty($args)) {

                $args .= ', ';

            }

            switch (gettype($a)) {

            case 'integer':

            case 'double':

                $args .= $a;

                break;

            case 'string':

                $a = htmlspecialchars(substr($a, 0, 64)).((strlen($a) > 64) ? '...' : '');

                $args .= "\"$a\"";

                break;

            case 'array':

                $args .= 'Array('.count($a).')';

                break;

            case 'object':

                $args .= 'Object('.get_class($a).')';

                break;

            case 'resource':

                $args .= 'Resource('.strstr($a, '#').')';

                break;

            case 'boolean':

                $args .= $a ? 'True' : 'False';

                break;

            case 'NULL':

                $args .= 'Null';

                break;

            default:

                $args .= 'Unknown';

            }

        }

        $output .= "<br />\n";

        $output .= "<b>file:</b> {$bt['line']} - {$bt['file']}<br />\n";

        $output .= "<b>call:</b> {$bt['class']}{$bt['type']}{$bt['function']}($args)<br />\n";

    }

    $output .= "</div>\n";

    return $output;

}



?>



And here's a sample of how the output looks like (the last call is on the top):



Backtrace:



file: 56 - /tmp/test.php

call: backtrace()



file: 53 - /tmp/test.php

call: test->bar(15.4, Array(4))



file: 61 - /tmp/test.php

call: test->test("making new object", True)



file: 65 - /tmp/test.php

call: foo(Resource(#2), Null)

ad-rotator.com
01-May-2004 12:11


To simply print out the file/function trace (chain of calls, file and line number before the error):



function getTrace() {

 $vDebug = debug_backtrace();

 $vFiles = array();

 for ($i=0;$i<count($vDebug);$i++) {

   // skip the first one, since it's always this func

   if ($i==0) { continue; }

   $aFile = $vDebug[$i];

   $vFiles[] = '('.basename($aFile['file']).':'.$aFile['line'].')';

 } // for

 $vTraceStr = implode(',',$vFiles);

}

spagmoid at yahoo dot NOSPAMcom
10-Dec-2003 03:47


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;

}

Fabian dot Kraetzer at gmx dot de
01-Sep-2003 09:18


I coded a function, too. Just call debug() evertime you think you could encounter an error:

<?

    function debug()

    {

        $debug_array = debug_backtrace();

        $counter = count($debug_array);

        for($tmp_counter = 0; $tmp_counter != $counter; ++$tmp_counter)

        {

          ?>

          <table width="558" height="116" border="1" cellpadding="0" cellspacing="0" bordercolor="#000000">

            <tr>

              <td height="38" bgcolor="#D6D7FC"><font color="#000000">function <font color="#FF3300"><?

              echo($debug_array[$tmp_counter]["function"]);?>(</font> <font color="#2020F0"><?

              //count how many args a there

              $args_counter = count($debug_array[$tmp_counter]["args"]);

              //print them

              for($tmp_args_counter = 0; $tmp_args_counter != $args_counter; ++$tmp_args_counter)

              {

                 echo($debug_array[$tmp_counter]["args"][$tmp_args_counter]);



                 if(($tmp_args_counter + 1) != $args_counter)

                 {

                   echo(", ");

                 }

                 else

                 {

                   echo(" ");

                 }

              }

              ?></font><font color="#FF3300">)</font></font></td>

            </tr>

            <tr>

              <td bgcolor="#5F72FA"><font color="#FFFFFF">{</font><br>

                <font color="#FFFFFF">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;file: <?

                echo($debug_array[$tmp_counter]["file"]);?></font><br>

                <font color="#FFFFFF">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;line: <?

                echo($debug_array[$tmp_counter]["line"]);?></font><br>

                <font color="#FFFFFF">}</font></td>

            </tr>

          </table>

          <?

         if(($tmp_counter + 1) != $counter)

         {

           echo("<br>was called by:<br>");

         }

       }

        exit();

    }

?>

bernyregeling AT hotmail DOT com
08-Aug-2003 07:29


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;


         }

jlim#natsoft.com.my
13-Mar-2003 09:51


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;

    }

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