set_error_handler

Jacob Slomp (2013-06-04 22:56:58)

This might be handy if you don't want your clients to see the errors, and you do want to be one step ahead of them.

It emails you the errors even if it's a parse error.

set_error_handler() doesn't work for what I wanted.

<?php
ini_set('log_errors',TRUE);
ini_set('error_log','tiny_uploads/errors.txt');

if($_SERVER['REMOTE_ADDR'] != "YOUR IP ADDRESS"){
    ini_set('display_errors',false);
}
   
function byebye(){

        $dir = dirname(__FILE__);
        if(file_exists($dir."/tiny_uploads/errors.txt")){
        
            $errors = file_get_contents($dir."/tiny_uploads/errors.txt");
            
            if(trim($errors)){
            
                $head = "From: php_errors@".str_replace('www.','',$_SERVER['HTTP_HOST'])."\r\n";
                
                $errors .= "---------------------------------------------\n\n";
                
                $errors .= "\n\nServer Info:\n\n".print_r($_SERVER, 1)."\n\n";
                $errors .= "---------------------------------------------\n\n";
                
                $errors .= "\n\nCOOKIE:\n\n".print_r($_COOKIE, 1)."\n\n";
                $errors .= "---------------------------------------------\n\n";
                
                $errors .= "\n\nPOST:\n\n".print_r($_POST, 1)."\n\n";
                $errors .= "---------------------------------------------\n\n";
                
                $errors .= "\n\nGET:\n\n".print_r($_GET, 1)."\n\n";
                
                
                mail("YOUR@EMAIL.COM","PHP Error ".$_SERVER['HTTP_HOST']."", $errors , $head);
                
                $fp = fopen($dir."/tiny_uploads/errors.txt","w+");
                fputs($fp, "");
                fclose($fp);    
            }    
        }
}
register_shutdown_function("byebye");
?>

Philip (2013-05-28 19:10:53)

By this function alone you can not catch fatal errors, there is a simple work around. Below is part of my error.php file which handles errors and exceptions in the application. Before someone complains I'll add that I do not care that I am using globals, this file is part of my mini framework and without the 'config' variable the application would crash anyways.

<?php

/**
 * Error handler, passes flow over the exception logger with new ErrorException.
 */
function log_error( $num, $str, $file, $line, $context = null )
{
    log_exception( new ErrorException( $str, 0, $num, $file, $line ) );
}

/**
 * Uncaught exception handler.
 */
function log_exception( Exception $e )
{
    global $config;
    
    if ( $config["debug"] == true )
    {
        print "<div style='text-align: center;'>";
        print "<h2 style='color: rgb(190, 50, 50);'>Exception Occured:</h2>";
        print "<table style='width: 800px; display: inline-block;'>";
        print "<tr style='background-color:rgb(230,230,230);'><th style='width: 80px;'>Type</th><td>" . get_class( $e ) . "</td></tr>";
        print "<tr style='background-color:rgb(240,240,240);'><th>Message</th><td>{$e->getMessage()}</td></tr>";
        print "<tr style='background-color:rgb(230,230,230);'><th>File</th><td>{$e->getFile()}</td></tr>";
        print "<tr style='background-color:rgb(240,240,240);'><th>Line</th><td>{$e->getLine()}</td></tr>";
        print "</table></div>";
    }
    else
    {
        $message = "Type: " . get_class( $e ) . "; Message: {$e->getMessage()}; File: {$e->getFile()}; Line: {$e->getLine()};";
        file_put_contents( $config["app_dir"] . "/tmp/logs/exceptions.log", $message . PHP_EOL, FILE_APPEND );
        header( "Location: {$config["error_page"]}" );
    }
    
    exit();
}

/**
 * Checks for a fatal error, work around for set_error_handler not working on fatal errors.
 */
function check_for_fatal()
{
    $error = error_get_last();
    if ( $error["type"] == E_ERROR )
        log_error( $error["type"], $error["message"], $error["file"], $error["line"] );
}

register_shutdown_function( "check_for_fatal" );
set_error_handler( "log_error" );
set_exception_handler( "log_exception" );
ini_set( "display_errors", "off" );
error_reporting( E_ALL );

dorphalsig at NOSPAMgmail dot com (2011-10-06 11:25:44)

This actually works to catch Fatal errors...

<?php
function shutdown()
{
    $a=error_get_last();
    if($a==null)   
        echo "No errors";
    else
         print_r($a);
    
}
register_shutdown_function('shutdown');
ini_set('max_execution_time',1 );
sleep(3);
?>

it will output
Array ( [type] => 1 [message] => Maximum execution time of 1 second exceeded [file] => /path/to/file_name.php [line] => 136 )

francois vespa (2010-12-22 15:27:14)

This is a note when using php from the terminal (the CLI interface). From the command line, even if you have some kind of error user handler function so STDERR will not display, fatal errors will still cause the PHP interpreter to display error text. There is nothing you can do about that php-wise. If using UNIX/Linux, you can add " 2>/dev/null" at the end of your command to force STDERR not to show

periklis (2010-08-02 08:09:00)

How to handle fatal errors in php 5.2:

<?php
register_shutdown_function('shutdownFunction');
function shutDownFunction() { 
    $error = error_get_last();
    if ($error['type'] == 1) {
        //do your stuff     
    } 
}
?>

contact [a] ionisis [.] com (2010-05-25 15:54:32)

There seems to be no way to access to access the _POST, _GET, etc if you call trigger_error from within a function inside a class file.

devermin at ti0n dot net (2010-05-23 03:46:50)

At work I have some code with errors that uncatched are the causes of integrity loss (people calling web services with file_get_contents that fails silently and afterwards insert garbage in the database). 

here is the solution I found to transform a specific set of errors into exception and afterwards be able to selectively act (with the error code) regarding categories :  

<?php
ini_set('error_reporting',E_ALL^E_NOTICE);

## first 10 bits reserved for the initial error number
define('EMASK',(~0)<<10);
define('ECODEMASK',~EMASK);
## categories 
define('IOERROR', 1<<10);
define('EMPTYPARMS', 1<<11);
define('FAILURE', 1<<12);
## string error patterns => code 

$catch_me=array(
    "/^(file_get_contents)\((.*)\).*failed to open stream: (.*)/ " => 
        array ( 'mesg' => "IO::Failed to open stream with",
                'code' => IOERROR | FAILURE
        ),
    "/^fopen\(.*\): Filename cannot be empty/" => 
        array( 'msg' => "Parameters::empty",
                'code' => EMPTYPARMS
        )
    );
function error_2_exception($errno, $errstr, $errfile, $errline,$context) {
    global $catch_me;
    foreach ($catch_me as $regexp  => $res) {
        if(preg_match($regexp,$errstr,$match)){
            throw new Exception($res['mesg'],$res['code']|( $errno & EMASK ) );
        }
    }
    /* switch back to PHP internal error handler  */
    return false;
}
## => want to catch this one
$f=file_get_contents("mlsdkfm");
## dont want to break existing wrong behaviour yet (so not caught)
$f=file_get_contents('');
## magic
set_error_handler("error_2_exception");
## behaviour remains the same
$f=file_get_contents('');
try { 
## web services that dont work now raise an exception \o/
$f=file_get_contents("mlsdkfm");
} catch(Exception $e) {
## and I can group my exception by category
    echo ( $e->getCode() & FAILURE )  ? "\nEPIC FAIL\n" : "\nbegnine";
}

?>

kalle at meizo dot com (2009-12-18 06:11:03)

This may be of help to someone, who is/was looking for a way to get a backtrace of fatal errors such as maximum memory allocation issues, which can not be handled with user-defined functions, to pin-point the problem:

On a server hosting many sites that share common PHP includes, I set in one spot:

<?php
@ini_set ("error_log", "/my/path/php.err-" . $_SERVER ["HTTP_HOST"] . "-" . $_SERVER ["REMOTE_ADDR"] . "-" . $_SERVER ["REQUEST_METHOD"] . "-" . str_replace ("/", "|", $_SERVER ["REQUEST_URI"]));
?>

I actually used some additional information too from my software that I omitted, but that way, you'll find errors sorted more neatly in for example:-

/my/path/php.err-website.com-127.0.0.1-GET-path|index.html?xyz 

And that at least helped me tremendously to then further pin-point where the problem is, as opposed to before just seeing the out of memory and not knowing which site/page it was on (as the PHP error only contains the very latest PHP code where it ran out of memory, which usually is just a shared included file, not the actual page).

webmaster at raphaelmichel dot de (2009-09-05 11:33:05)

If you want to use the configuration from error_reporting() in your error_handler, use this at the begin of the function:
$rep = ini_get('error_reporting');
if(!($rep & $fehlercode)) return false;

quickshiftin at gmail dot com (2009-07-01 07:59:53)

using the output_buffer as a way to trap fatal errors from php itself, like E_ERROR, cannot offer a complete solution, b/c output buffering is disabled on the cli since 4.3.5 ..

nizamgok at gmail dot com (2009-06-15 19:27:50)

I have realized that a few people here mentioned that you cannot capture parse errors (type 4, E_PARSE). This is not true. Here is how I do. I hope this helps someone.

1) Create a "auto_prepend.php" file in the web root and add this:

<?php
register_shutdown_function('error_alert');

function error_alert()
{
        if(is_null($e = error_get_last()) === false)
        {
                mail('your.email@example.com', 'Error from auto_prepend', print_r($e, true));
        }
}
?>

2) Then add this "php_value auto_prepend_file /www/auto_prepend.php" to your .htaccess file in the web root.

* make sure you change the email address and the path to the file.

nsg (2009-05-13 16:58:35)

If using E_USER_ERROR in conjunction with a custom error-handler, we are faced with an annoying choice:
If you choose to die() on such errors, __destruct()ors can still function, but we can't then return false and have the inbuilt handler log the error.
If you return false thus allowing the error to be logged, the script will halt, exit() style, and __destruct()'s won't happen.
It seems the only solutions in such a case is to a) log your own errors, or b) don't use E_USER_ERROR.

Marcelius (2009-01-22 05:41:14)

Another way to catch PHP's fatal errors:

<?php
    error_reporting(E_ALL);
    ini_set('display_errors', 0);

    function shutdown(){
        $isError = false;
        if ($error = error_get_last()){
            switch($error['type']){
                case E_ERROR:
                case E_CORE_ERROR:
                case E_COMPILE_ERROR:
                case E_USER_ERROR:
                    $isError = true;
                    break;
            }
        }

        if ($isError){
            echo "Script execution halted ({$error['message']})";
        } else {
            echo "Script completed";
        }
    }

    register_shutdown_function('shutdown');
?>

Note that this will only catch runtime errors. So calling a method in a non existing class, or declaring a function twice does not trigger the shutdown handler.

wfinn at riverbed dot com (2008-07-09 18:15:22)

"The following error types cannot be handled with a user defined function: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING, and most of E_STRICT raised in the file where set_error_handler() is called."

This is not exactly true.  set_error_handler() can't handle them, but ob_start() can handle at least E_ERROR.

<?php

function error_handler($output)
{
    $error = error_get_last();
    $output = "";
    foreach ($error as $info => $string)
        $output .= "{$info}: {$string}\n";
    return $output;
}

ob_start('error_handler');

will_this_undefined_function_raise_an_error();

?>

jonbarnett at gmail dot com (2008-04-11 07:42:21)

Per the comment below:
There's no problem with static class functions.
The proper way to set a callback for a static class function is:
array("Classname", "functionname")
The class name is a string. If you don't quote the string, PHP treats it as a barestring and triggers a notice.
/manual/en/language.pseudo-types.php

Alexey Letoshnikov (2008-04-04 05:48:04)

There is a problem to set a static function as error handler
<?php
class Debug
{
    public static function test($num,$err,$file,$line)
    {
        return true;
    }
}
?>

<?php set_error_handler(array(Debug,'test')); ?>
Static function accepted by set_error_handler() and works but php generates E_NOTICE "Use of undefined constant Debug"

<?php set_error_handler('Debug::test')); ?>
Static function accepted by set_error_handler but does not work

Finaly decided to create a __construct() method and set it as error handler.
<?php set_error_handler(array(new Debug(),'test')); ?>

etienne at perval dot fr (2008-03-04 03:17:55)

Note that this function may return NULL in some cases, even when there are no errors.
For instance, this is the case when you call this function for the first time: the function returns NULL simply because there is no previous error handler defined.

m0sh3 at hotmail dot com (2008-02-05 09:33:02)

Looks like there's no way to distinguish between catched exceptions thrown by internal classes and real warnings in custom error handlers:

<?php
function handleError($n, $m, $f, $l) {
    //no difference between excpetions and E_WARNING
    echo "user error handler: e_warning=".E_WARNING."  num=".$n." msg=".$m." line=".$l."\n";
    return true;
    //change to return false to make the "catch" block execute;
}
set_error_handler('handleError');
//turn off to make try/catch work normally

//uncomment this for a regular warning
timezone_open(1202229163);

//comment this whole try/catch out to see new DateTimeZone outside of a try / catch
//behavior is the same if you have set a custom error handler

//echo new DateTimeZone(1202229163);

//*
try {
    $z = new DateTimeZone(1202229163);
} catch (Exception $e) {
    echo "caught";
}
// */
?>

webmaster at paramiliar dot com (2008-01-03 23:03:52)

We needed to use an error handler to handle SQL errors while passing the query along so the query is also logged and this is what we came up with, its kind of an ugly bridge but it works 100%

<?php

function myErrorHandler($errno, $errstr, $errfile, $errline){
    switch ($errno) {
    case E_USER_ERROR:
        if ($errstr == "(SQL)"){
            // handling an sql error
            echo "<b>SQL Error</b> [$errno] " . SQLMESSAGE . "<br />\n";
            echo "Query : " . SQLQUERY . "<br />\n";
            echo "On line " . SQLERRORLINE . " in file " . SQLERRORFILE . " ";
            echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
            echo "Aborting...<br />\n";
        } else {
            echo "<b>My ERROR</b> [$errno] $errstr<br />\n";
            echo "  Fatal error on line $errline in file $errfile";
            echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
            echo "Aborting...<br />\n";
        }
        exit(1);
        break;

    case E_USER_WARNING:
    case E_USER_NOTICE:
    }
    /* Don't execute PHP internal error handler */
    return true;
}

// function to test the error handling

function sqlerrorhandler($ERROR, $QUERY, $PHPFILE, $LINE){
    define("SQLQUERY", $QUERY);
    define("SQLMESSAGE", $ERROR);
    define("SQLERRORLINE", $LINE);
    define("SQLERRORFILE", $PHPFILE);
    trigger_error("(SQL)", E_USER_ERROR);
}

set_error_handler("myErrorHandler");

// trigger an sql error
$query = "SELECT * FROM tbl LIMIT 1";
$sql = @mysql_query($query)
    or sqlerrorhandler("(".mysql_errno().") ".mysql_error(), $query, $_SERVER['PHP_SELF'], __LINE__);
    

?>

michal dot kocarek at NO_SPAM dot seznam dot cz (2007-09-23 02:55:03)

Be aware of efficiency and speed of your scripts!

If you use old-fashioned non-strict variable calling (example follows...), your custom error handler function degrades the script speed very big (especially for bigger projects). Because of for every "use of undefined constant" or "undefined variable" E_NOTICEs will be called your own custom error handler function.

<?
if ($form_variable) { ///< E_NOTICE Undefined variable
   // process form stuff
}
$foo[bar] = $const_array[baz]; ///< 2x E_NOTICE Use of undefined constant bar, baz

if (!$d) { // declare default $d ///< E_NOTICE Undefined variable
   $d = 5;
}
?>

As you can see in this poor example, badly writted scripts decrease the performace very big 'cause of the error handler is called almost everytime. So use custom-error-handler on heavily used pages only if you are writing scripts strictly. (Example follows:)
<?
if (isset($form_variable) && $form_variable != null) {
   // process form stuff
}
$foo['bar'] = $const_array['baz'];

if (!isset($d) || $d == null) {
   $d = 5;
}
?>

ash (2007-08-04 03:38:05)

error handling function that handles both errors and exceptions; also features a backtrace including possible function arguments.

<?php

$cfg = array();
$cfg['debug'] = 1;
$cfg['adminEmail'] = 'name@domain.tld';

function errorHandler($errno, $errstr='', $errfile='', $errline='')
{
    // if error has been supressed with an @
    if (error_reporting() == 0) {
        return;
    }

    global $cfg;

    // check if function has been called by an exception
    if(func_num_args() == 5) {
        // called by trigger_error()
        $exception = null;
        list($errno, $errstr, $errfile, $errline) = func_get_args();

        $backtrace = array_reverse(debug_backtrace());

    }else {
        // caught exception
        $exc = func_get_arg(0);
        $errno = $exc->getCode();
        $errstr = $exc->getMessage();
        $errfile = $exc->getFile();
        $errline = $exc->getLine();

        $backtrace = $exc->getTrace();
    }

    $errorType = array (
               E_ERROR            => 'ERROR',
               E_WARNING        => 'WARNING',
               E_PARSE          => 'PARSING ERROR',
               E_NOTICE         => 'NOTICE',
               E_CORE_ERROR     => 'CORE ERROR',
               E_CORE_WARNING   => 'CORE WARNING',
               E_COMPILE_ERROR  => 'COMPILE ERROR',
               E_COMPILE_WARNING => 'COMPILE WARNING',
               E_USER_ERROR     => 'USER ERROR',
               E_USER_WARNING   => 'USER WARNING',
               E_USER_NOTICE    => 'USER NOTICE',
               E_STRICT         => 'STRICT NOTICE',
               E_RECOVERABLE_ERROR  => 'RECOVERABLE ERROR'
               );

    // create error message
    if (array_key_exists($errno, $errorType)) {
        $err = $errorType[$errno];
    } else {
        $err = 'CAUGHT EXCEPTION';
    }

    $errMsg = "$err: $errstr in $errfile on line $errline";

    // start backtrace
    foreach ($backtrace as $v) {

        if (isset($v['class'])) {

            $trace = 'in class '.$v['class'].'::'.$v['function'].'(';

            if (isset($v['args'])) {
                $separator = '';

                foreach($v['args'] as $arg ) {
                    $trace .= "$separator".getArgument($arg);
                    $separator = ', ';
                }
            }
            $trace .= ')';
        }

        elseif (isset($v['function']) && empty($trace)) {
            $trace = 'in function '.$v['function'].'(';
            if (!empty($v['args'])) {

                $separator = '';

                foreach($v['args'] as $arg ) {
                    $trace .= "$separator".getArgument($arg);
                    $separator = ', ';
                }
            }
            $trace .= ')';
        }
    }

    // display error msg, if debug is enabled
    if($cfg['debug'] == 1) {
        echo '<h2>Debug Msg</h2>'.nl2br($errMsg).'<br />
            Trace: '.nl2br($trace).'<br />';
    }

    // what to do
    switch ($errno) {
        case E_NOTICE:
        case E_USER_NOTICE:
            return;
            break;

        default:
            if($cfg['debug'] == 0){
                // send email to admin
                if(!empty($cfg['adminEmail'])) {
                    @mail($cfg['adminEmail'],'critical error on '.$_SERVER['HTTP_HOST'], $errorText,
                            'From: Error Handler');
                }
                // end and display error msg
                exit(displayClientMessage());
            }
            else
                exit('<p>aborting.</p>');
            break;

    }

} // end of errorHandler()

function displayClientMessage()
{
    echo 'some html page with error message';

}

function getArgument($arg)
{
    switch (strtolower(gettype($arg))) {

        case 'string':
            return( '"'.str_replace( array("\n"), array(''), $arg ).'"' );

        case 'boolean':
            return (bool)$arg;

        case 'object':
            return 'object('.get_class($arg).')';

        case 'array':
            $ret = 'array(';
            $separtor = '';

            foreach ($arg as $k => $v) {
                $ret .= $separtor.getArgument($k).' => '.getArgument($v);
                $separtor = ', ';
            }
            $ret .= ')';

            return $ret;

        case 'resource':
            return 'resource('.get_resource_type($arg).')';

        default:
            return var_export($arg, true);
    }
}

?>

Thomas (2007-07-18 01:57:43)

Be careful with error-handlers if you are using require() with a function as argument, like
<?php 
  require(foo($foo));
?>
If the result of the function isn't a valid file to be included, you wont get any errormessage, but your script will crash without any output (see the bug-database for further details: http://bugs.php.net/bug.php?id=41862).

stepheneliotdewey at GmailDotCom (2007-06-26 21:26:37)

Additional note based on some further testing:
Although errcontext is effectively an array passed by reference to your custom error handling function, you cannot simply copy it over to another variable, because that variable will also act like a reference to errcontext, almost like an object.
Instead, the only way I can find to copy the errcontext array to a separate variable so that you can actually modify its values without changing the surrounding variable context, is to copy it piece-by-piece with a foreach loop. Not the most efficient way of working, but then again, errors are hopefully exceptional enough for you that performance will not be an overriding concern in this case.

stepheneliotdewey at GmailDotCom (2007-06-26 20:48:48)

The manual states:
"errcontext will contain an array of every variable that existed in the scope the error was triggered in. User error handler must not modify error context."
But do you know WHY you must not modify the error context? It appears that errcontext is (in effect if not literally) created by taking $GLOBALS and adding the non-global local variables as additional entries in that array, then passing the whole thing *by reference*.
(You can prove this to be true if you set up a custom error handler and then print_r($errcontext) within it, because $GLOBALS will be printed as a recursive array).
In other words, the language in the manual is misleading, because errcontext is NOT a copy of the variables that existed when the error WAS triggered, but rather is a reference to the *existing LIVE variables* in the calling script.
This includes superglobal variables like $_SERVER, $_POST, $_GET, etc., as well as all user-defined variables in scope.
The significance of that is that if you modify errcontext, you will be modifying those other variables, not just for the life of your error handling function, but for the life of the calling script as well.
That doesn't matter if you plan to halt execution in your error handling function, but it will lead to unexpected behavior if you modify $errcontext and then return to the program's normal flow after handling the error, because the variables will stay modified. For example, if you unset $_SERVER in your custom error handling function, it will remain unset once the function is over and you have returned to the page that generated the error.
This should be made clearer in the manual, starting by marking errhandler with an ampersand (&) for passage by reference in the "Parameters" section above, like so:
handler ( int $errno, string $errstr [, string $errfile [, int $errline [, array &$errcontext]]] )

gotrunko at hotmail dot com (2007-06-20 01:26:20)

To ereg error in a text file

<?php
$log_file="log.txt";

set_error_handler(log_handler);

function log_handler ( $errno, $errstr,  $errfile, $errline, $errcontext )
{
    $context = var_export($errcontext, TRUE);
    log_error_ereg("errno:$errno ($errstr) file:$errfile, line:$errline, context:$context\n");
}

function log_error_ereg($mess)
{
    global $log_file;

    $fd = fopen($log_file, 'a');
    if(!$fd)
    {
        echo "<pre>$mess</pre>";
    }
    else
    {
        if(!fwrite($fd, date('Y-m-d H:i:s')." ERR : \n$mess\n\n"))
        {
            echo "<pre>$mess</pre>";
        }
        fclose($fd);
    }
}
?>

greg sidberry[poetics5 at yahoo dot com] (2007-05-15 22:32:09)

I was using a class, and needed to have a function within it handle php errors.
The following code will allow you to call a class function of already defined object while maintaining access to all the objects current data .
============================
set_error_handler("classPassPHPError");
$ObjectName="test";
$test->new className;
function classPassPHPError($errno, $errstr, $errfile, $errline){
global $ObjectName;
eval("global \$".$ObjectName.";");
eval("\$object=\$".$ObjectName.";");
$object->phpErrorHandler($errno, $errstr, $errfile, $errline);
$object=null;
}

silkensedai at online dot fr (2007-05-02 00:37:14)

i made an error handler that print also the backtrace and that can die on some errors. It can be useful if you want to die on every error you find.

<?php

function my_error_handler($errno, $errstr, $errfile, $errline){
    $errno = $errno & error_reporting();
    if($errno == 0) return;
    if(!defined('E_STRICT'))            define('E_STRICT', 2048);
    if(!defined('E_RECOVERABLE_ERROR')) define('E_RECOVERABLE_ERROR', 4096);
    print "<pre>\n<b>";
    switch($errno){
        case E_ERROR:               print "Error";                  break;
        case E_WARNING:             print "Warning";                break;
        case E_PARSE:               print "Parse Error";            break;
        case E_NOTICE:              print "Notice";                 break;
        case E_CORE_ERROR:          print "Core Error";             break;
        case E_CORE_WARNING:        print "Core Warning";           break;
        case E_COMPILE_ERROR:       print "Compile Error";          break;
        case E_COMPILE_WARNING:     print "Compile Warning";        break;
        case E_USER_ERROR:          print "User Error";             break;
        case E_USER_WARNING:        print "User Warning";           break;
        case E_USER_NOTICE:         print "User Notice";            break;
        case E_STRICT:              print "Strict Notice";          break;
        case E_RECOVERABLE_ERROR:   print "Recoverable Error";      break;
        default:                    print "Unknown error ($errno)"; break;
    }
    print ":</b> <i>$errstr</i> in <b>$errfile</b> on line <b>$errline</b>\n";
    if(function_exists('debug_backtrace')){
        //print "backtrace:\n";
        $backtrace = debug_backtrace();
        array_shift($backtrace);
        foreach($backtrace as $i=>$l){
            print "[$i] in function <b>{$l['class']}{$l['type']}{$l['function']}</b>";
            if($l['file']) print " in <b>{$l['file']}</b>";
            if($l['line']) print " on line <b>{$l['line']}</b>";
            print "\n";
        }
    }
    print "\n</pre>";
    if(isset($GLOBALS['error_fatal'])){
        if($GLOBALS['error_fatal'] & $errno) die('fatal');
    }
}

function error_fatal($mask = NULL){
    if(!is_null($mask)){
        $GLOBALS['error_fatal'] = $mask;
    }elseif(!isset($GLOBALS['die_on'])){
        $GLOBALS['error_fatal'] = 0;
    }
    return $GLOBALS['error_fatal'];
}

?>

Usage :

<?php
error_reporting(E_ALL);      // will report all errors
set_error_handler('my_error_handler');
error_fatal(E_ALL^E_NOTICE); // will die on any error except E_NOTICE
?>

elven_rangers at yahoo dot com (2007-02-14 04:22:55)

Unfortunately, none of the procedures described here by other users to catch all errors work.
Then again this would be impossible as parse errors are triggered before the code is interpreted and executed so no code solution is possible (just as the documentation says).
You can test them easily against this simple code:
some_function_that_doesnt_exist();
using it in this form will trigger a Fatal Error (call to undefined function), which can't be caught by using your custom defined handler but *can* be caught by using the solutions presented by other programmers.
if you remove the ; from the end will trigger a Parse Error (syntax error), which *can't* be caught by any of these solutions. If this called is however places as the last line of code, just before the ?> then it will again generate a Fatal Error (call to undefined function).
if you further remove the () then you'll get a Notice (undefined constant) which can be caught by the manual method of defining a custom error handler.

mail at chernousov dot com (2006-10-24 03:52:09)

When fatal error occurs, class destructors are not executed.

<?

class someClass {
  function __construct() {
    echo '__construct()';
  }

  function __destruct() {
    echo '__destruct()';
  }
}

$someClass = new someClass();
someNonExistentFunction();

?>

Result will be:

__construct()
Fatal error: Call to undefined function someNonExistentFunction() in tes.php on line 14

alexey.kupershtokh.gmail (2006-10-02 00:07:40)

2errd
I've got more convenient and safe error to exception converter:
class CustomException extends Exception {
public static function errorHandlerCallback($code, $string, $file, $line, $context) {
$e = new self($string, $code);
$e->line = $line;
$e->file = $file;
throw $e;
}
}
set_error_handler(array("CustomException", "errorHandlerCallback"), E_ALL);

dk at brightbyte dot de (2006-08-27 16:09:14)

Sometimes, you want to "catch" only some errors, and let the default handler deal with the result. I just found out that (at least in PHP 5), the default handler will be called if you return false (not 0 or NULL or '', but false) from your custom handler. This allows for "chaining" handlers.
The fature was suggested in this thread:
http://www.zend.com/lists/php-dev/200405/msg00491.html - the initial suggestion was to call the default handler if true is returned, but this was changed later on, apperently.

jla (2006-07-27 16:16:41)

Other option to "handle" ALL errors
set_error_handler("yourHandler");
// Parse,Compile, Core, etc... Errors
ini_set('html_errors',false);
ini_set('error_prepend_string','<html><head><META http-equiv="refresh" content="0;URL=/error.php?msg=');
ini_set('error_append_string','"></head></html>');

kariedoo (2006-05-08 01:07:10)

function errorlog($type, $info, $file, $row)
{
if ($handle = fopen("./log/ftp_error.log", "a"))
{
@fwrite($handle, date("Y-m-d H:i:s")." "--> $type: $info FILE: $file - Row $row\r\n" );
@fclose($handle);
}//end if
}//end function
### in the error logging code for example ftp: ###
set_error_handler("errorlog"); //set your own Handler

$this->connect = ftp_connect(TXTCONNECT);
$this->login = ftp_login($this->connect, TXTID, FTPPASS);
$this->systype= ftp_systype($this->connect);
restore_error_handler(); //restore the old handler
------------------
content in file
------------------
2006-05-08 09:36:02 2: ftp_login(): Login incorrect. FILE: /html/cgi-bin/test/classes/ftp.class.php - Row 63

docey (2006-04-05 12:50:55)

if you wan't to know the current error-handler
set use something like this:
$current_errorhandler = set_error_handler("myerrorhandler");
restore_error_handler();
this will set your custom error_handler and return
the name of the previous set error handler. by
calling restore_error_handler, you remove your
custom error_handler and set the error_handler that
was set back again.
this way you can also switch back to php-default error-handler
without knowing how many error-handler already
are set, by using a loop till an empty string is
returned. because an empty string means
"no error-handler set" wich means php's default
errorhandler is set back.
like in this code below:
function restore_phperrorhandler()
{
// get current error handler.
$previous_errorhandler =
set_error_handler("myerrorhandler");
restore_error_handler();
$max_loops = 20;
$cur_loops = 0;

// if current error handler is not already php's or fails.
if(($previous_errorhandler != NULL) OR
($previous_errorhandler != "")){

while($previous_errorhandler != ""){
$cur_loops = $cur_loops + 1;

// check if not exceeding infinit loop.
if($cur_loops >= $max_loops){
trigger_error("Restoring exceeds max. loops.",
E_USER_WARNING);
return false;
}

//switch to previous handler.
restore_error_handler();

// get its name and switch to it again.
$previous_errorhandler =
set_error_handler("myerrorhandler");
restore_error_handler();

// check if getting errorhandler failed.
if($previous_errorhandler == NULL){
trigger_error("Failed to get prev. error handler",
E_USER_WARNING);
return false;

// empty string = php-default error handler
}elseif($previous_errorhandler == ""){
return true;
}
}
}else{
trigger_error("Current Error-Handler is default.",
E_USER_NOTICE);
return true;
}
}
this function will loop and return true when no
error handler is left. leaving php-default handler
in controll again. this is usefull if you want to
disable your own error-handler but be sure that
php's is handling your error's and not any other
error-handler.

errd (2006-01-30 05:52:23)

In errors to exceptions conversion below I found some incorrect stuff. File and line properties of Exception point to line and file where Exception is thrown, but not where real error is occured.

Impoved errors to exceptions converting:
+ Fixed filename of exception handled
+ Fixed code line of exception handled

<?php 

class CustomException extends Exception { 
    public function setLine($line) {  
        $this->line=$line; 
    } 
     
    public function setFile($file) { 
        $this->file=$file; 
    } 
} 

function exceptionsHandler($code, $string, $file, $line) {  
    $exception=new CustomException($string, $code); 
    $exception->setLine($line); 
    $exception->setFile($file); 
    throw $exception; 
}  

set_error_handler('exceptionsHandler', E_ALL); 

?>

(2006-01-24 01:19:38)

To honor the value of PHP's error_reporting() function, use:

<?
  if( ($level & error_reporting()) == 0 ) return;
?>

Gulopine (2006-01-05 09:36:23)

Also note that even though the documentation states "errcontext will contain an array of every variable that existed in the scope the error was triggered in," that is not the case for $this in an instantiated object, as of PHP 5.1.1.

<?php

function error_function($errno, $errstr, $errfile, $errline, $errcontext) {
    print_r($errcontext);
}

set_error_handler('error_function');

class test_class {
    private $id;
    
    function __construct($id) {
        $this->id = $id;
        trigger_error('Test error');
    }
}

$test = new test_class(5);

?>

Result:

Array
(
    [id] => 5
)

I discovered this when trying to write an error handler that would log the class the error occured in, as it was triggered from a function in a parent class extended by several individual classes.

ia [AT] zoznam [DOT] sk (2005-09-22 04:33:35)

as reply to dawiddr at gmail dot com:
Be careful with this when using __autoload(). When there is some error during parsing the file included in __autoload() so an exception is thrown, it results in following error:
Fatal error: Function __autoload(ClassName) threw an exception of type 'Exception' in /network/webroot/dev/test.php on line 121
It is because exceptions can't be thrown in __autoload().
See __autoload() documentation (http://www.php.net/autoload) and bug #31102 (http://bugs.php.net/bug.php?id=31102&edit=3)

florian at siweho dot de (2005-08-22 12:26:33)

@ mmtache at yahoo dot com
you have to use
if(error_reporting() != 0){
.... (yourOwnHandler)
instead of
if(error_reporting()){
....
in PHP5. then operations like this "@fopen" won't show an error-message

eregon at eregon dot info (2005-08-02 09:35:07)

It is not possible to handle fatal errors with own handler. Even if you have set your own handler, fatal error will be always handled by PHP's default handler. The reason is the script may be in unstable state after fatal error occurence (details here: http://marc.theaimsgroup.com/?l=php-dev&m=97673386418430&w=2).

dawiddr at gmail dot com (2005-07-05 16:01:53)

In PHP5, if you want to have exceptions thrown instead of normal errors - you could use an error handler, which throw exceptions:

<?php

function handler($errno, $errstr, $errfile, $errline) 
{
    print "Error handled!\n";
    throw new Exception($errstr, $errno);
}

set_error_handler('handler');

try
{
    print 2 / 0; // simple error - division by zero
    print "This will never be printed";
}
catch (Exception $e)
{
    print "Exception catched:\n";
    print "Code: ".$e->getCode()."\n";
    print "Message: ".$e->getMessage()."\n";
    print "Line: ".$e->getLine();
}

?>

Result:

Error handled!
Exception catched:
Code: 2
Message: Division by zero
Line: 6

As you see, exception is catched like it have been thrown by division by zero - in try/catch clause. But line numer and backtrace shows, that is was thrown by the error handler.

frank at ethisoft dot nl (2005-06-01 03:11:17)

Perhaps it is worth mentioning that in 
PHP5 
both set_error_handler & set_exception_handler can be called with an array containing 2 arguments:
1) var  ==> object
2) string ==> name of handler function in object

EXAMPLE:
<?php
set_error_handler               (array($object, 'handler_function'));
set_exception_handler      (array($object, 'handler_function'));
?>

Both can point to the same object and handler_function so that both error and exception handling, which are very much alike usually, can be done by only 1 dedicated class.

jgiglio at netmar dot com (2005-03-25 20:02:57)

set_error_handler also overrides the default behavior of postgresql which is to shoot HTML errors to the browser on a query failure or other database error.
I can't find a list of symbolic $errno names for postgres errors, but a normal "bad query" throws an errno of 2.
Be careful to not use an empty default case in your errno case statement if you use postgresql, and expect php to generate DB errors automatically.

Steffen Staehle (2005-01-12 02:29:46)

Two notes on using set_error_handler() on behaviour that I noticed when migrating an application from php 4.2.1 to php 4.3.9 (I do not yet have php 5.0 available, this might not apply there!).

1. setting the system error handler

If you want to set the standard php error handler again, after having set your own error handler, this works in php 4.2.1 by passing in an empty string:

<?php

   function my_handler($log_level, $log_text, $error_file, $error_line)
   {
      // if an error occurs here, the standard error
      // would be called (to avoid recursion)

      // do something useful
      // ...
   }

   $last_handler = set_error_handler("my_handler");

   // after this, $last_handler == ""

   // restore standard error handler

   $last_handler = set_error_handler("");

   // after this, $last_handler == "my_handler"

?>

The very same code now raises an error in php 4.3.9:

   set_error_handler() expects argument 1, '', to be a valid callback

(Since the return value of the first call to set_error_handler() is still the empty string "", I don't see how this can be done any more. I don't really need this, because I use my own handlers as shown below, but it might be good to be aware of this.)

2. setting your own 'second level' handler

If you have set your own error handler, and want to replace it by another one (other than the standard php error handler) while it is being executed, note that the return value of set_error_handler when used INSIDE the error handler is "" instead of the name of the previous handler! This is not too surprising, because during execution of your self defined error handler, php replaces it with the standard php error handler to avoid infinite loops in case of problems inside the handler. This is only interesting if you want nested handlers as I do. Background of my design:

   1st level handler: log into DB
   2nd level handler: log into flat file (if log into DB fails)
   3rd level handler: print to stdout (if log into flat file fails) (this is the sytem handler, finally).

<?php

   function my_fallback_handler($log_level, $log_text, $error_file, $error_line)
   {
      // if an error occurs here, the standard error
      // would be called (to avoid recursion)

      // do something useful
      // ...

   } // my_fallback_handler

   function my_handler($log_level, $log_text, $error_file, $error_line)
   {
      // if an error occurs here, the standard error
      // would be called (to avoid recursion)

      // but we want to have a fallback handler different
      // to the standard error handler

      $last_handler = set_error_handler("my_fallback_handler");

      // I expected $last_handler == "my_handler" 
      // (which it would outside my_handler())
      // but here it is the empty string ""

      // do something useful
      // ...

      // now set the 1st level handler again:
      // (do NOT use $last_handler as argument,
      // because it equals "")

      $last_handler = set_error_handler("my_handler");

   } // my_handler

   $last_handler = set_error_handler("my_handler");

?>

Sukender (2004-08-10 08:29:46)

In PHP5, ou can ask for the default handler to be called after your custom handler by returning "false". See this pseudo-code :
<?
function MyHandler($errno, $errstr, $errfile, $errline, $errcontext) {
    my_handling_code;        // Do something, such as sending an email to the admin
    if (i_want_to_call_the_default_handler) return false;        // will invoke the default error handler just after
    else return true;        // This will NOT invoke it (= you've properly handled the error)
}
set_error_handler("MyHandler");
?>

I have not tested the functionality, but I think that the php.ini directive "log_errors" keeps working, but *only* when you call the default handler (= retrun false).

>>> Source : Mailing list thread about "re-invoking default error handler" at http://www.zend.com/lists/php-dev/200405/msg00491.html (be careful about the first post : "true" and "false" are switched - because it's only a proposition).

Joe (2004-06-29 22:26:22)

When a custom error handler is set, the php.ini directive "log_errors" stops working. I'm guessing to favor your custom handler. You can still log your errors with the "error_log" function, but it doesn't happen when you have a custom error handler.

Cezary Tomczak (2004-04-22 01:25:16)

Here is a script to debug / display errors in a nice way: http://gosu.pl/demo/ErrorHandler/ErrorHandler.zip
Example of displaying an error: http://gosu.pl/demo/ErrorHandler/example1.html
Example of displaying source of the file where the error appeared: http://gosu.pl/demo/ErrorHandler/example2.html
Displaying error: generates a backtrace, show file / line, show function / arguments (and values), source of the file

erwin at isiz dot nl (2004-04-19 06:51:11)

@sijmen at digitized dot nl
That's not true. The reference operator does have effect, when used correctly.

Your code doesn't use the reference operator in the set_error_handler function, but it does when creating the new error object. In your case, you have to use the reference operator two times.

When calling the set_error_handler function

<?php
        set_error_handler(array(&$this, 'handler'));
?>

and when creating the class

<?php
$eh = &new error;
?>

In that case the same error class will be used and the output will be following:
Error! 
!!

Hope this helps.

mightye (at) mightye (dot) org (2004-04-12 14:18:31)

You can't use this functionality to catch parse errors in included, required, or eval()'d code. Parse errors seem to exist on a deeper level.

sijmen at digitized dot nl (2004-04-09 07:47:43)

@jayp at groovejob dot com
As I said before, the reference operator doesn't have any effect on the the error handler.
Proof of concepts:
http://trouby.digitized.nl/set_error_handler2.php
http://trouby.digitized.nl/set_error_handler2.php?source=1

jayp at groovejob dot com (2004-04-03 09:28:05)

In response to sijmen at digitized dot nl:
Instead of
$eh = new error;
use
$eh =& new error();
The new operator returns a copy of the error object, so the error handler that is set in the constructor is tied to a different object instance than the instance returned by "new". To make sure you are working with the exact same object instance that you think you are, it's best to use the reference object when creating instances of objects, like so:
$oMyObject =& new MyObject();
HTH,
Jay

sijmen at digitized dot nl (2004-03-30 07:23:31)

@skyrl at free dot fr
It seems that the reference operator '&' doesn't have any effect. That's why I submitted the comment. 

<?php
class error {
    var $error;

    function error() {
        $this->setIni();
    }

    function handler() {
        echo $this->error.'!!';
    }

    function setText($text) {
         $this->error = $text;
    }

    function setIni() {
        set_error_handler(array(&$this, 'handler')); // The '&' operator doesn't have any effect
    }
}

$eh = new error;
$eh->setText('Error! <br>'); // Will not get set

trigger_error('text', E_USER_ERROR); // prints '!!'
?>

Proof of concept
http://trouby.digitized.nl/set_error_handler.php
http://trouby.digitized.nl/set_error_handler.php?source=1

skyrl at free dot fr (2004-03-29 19:00:41)

in reaction to the last '29-Mar-2004 11:13' post, just have to say that's normal the values are not "saved" in your error handler object. because the error object of the handler is not the same object as the one you instantiate...
You have to write set_error_handler(array(&this, 'my_error_handler')). The & is important for php to know that your error handler belongs to the same instance you allocate.

(2004-03-29 16:13:33)

It seems that when you're letting PHP know that you have a custom  error handler, you're not able to -update/set new- variables inside the class. Example:

<?php
class error {
   var $error;

   function error() {
       $this->setIni();    // this causes PHP to ignore all other changes to the class.
   }

   function handler() {
       echo $this->error.'!!';
   }

   function setText($text) {
         $this->error = $text;
   }

   function setIni() {
       set_error_handler(array($this, 'handler'));
   }
}

$eh = new error;
$eh->setText('Error! <br>');  // this will not be saved

trigger_error('text', E_USER_ERROR);
// prints '!!'
?>

How it should be done:
<?php
class error {
   var $error;

   function error() {
         // dont let PHP know of our error handler yet
   }

   function handler() {
       echo $this->error.'!!';
   }

   function setText($text) {
         $this->error = $text;
   }

   function setIni() {
       set_error_handler(array($this, 'handler'));
   }
}

$eh = new error;
$eh->setText('Error! <br>');  // this WILL work
$eh->setIni();  // call this method when you're ready with configuring the class. All other methods that will be called will have no effect on the errorHandling by PHP

trigger_error('text', E_USER_ERROR);
// prints 'Error! <br>!!'
?>

phpmanual at NO_SPHAMnetebb dot com (2003-11-15 20:19:16)

Given this code:
class CallbackClass {
function CallbackFunction() {
// refers to $this
}
function StaticFunction() {
// doesn't refer to $this
}
}
function NonClassFunction() {
}
there appear to be 3 ways to set a callback function in PHP (using set_error_handler() as an example):
1: set_error_handler('NonClassFunction');
2: set_error_handler(array('CallbackClass', 'StaticFunction'));
3: $o =& new CallbackClass();
set_error_handler(array($o, 'CallbackFunction'));
The following may also prove useful:
class CallbackClass {
function CallbackClass() {
set_error_handler(array(&$this, 'CallbackFunction')); // the & is important
}

function CallbackFunction() {
// refers to $this
}
}
The documentation is not clear in outlining these three examples.

Thomas Staunton (2003-03-25 04:11:52)

The best way, I have found to use a class/object as an error handler is to define a class, add your desired error handling function into the constructor and then call set_error_handler() to the name of your function, thats it. e.g.
Class Error {
Function Error() {
Function HandleError($n, $m, $f, $l){
print_r(debug_backtrace());
}
set_error_handler('HandleError');
}
}

bob at db dot org (2003-03-11 13:09:54)

The documentation on this page kindly offers the following on using (class) methods as error handlers:

Note:  Instead of a function name, an array containing an object reference and a method name can also be supplied. (Since PHP 4.3.0)

Since that's all it says about the subject, I thought I'd offer a sample implementation to show how this can be used:

<?php

        class error {

                var $conf;
                var $lang;

                function error($conf, $lang) {
                        $this->conf = $conf;
                        $this->lang = $lang;

                        set_error_handler(array(&$this, 'handler'));
                }

                function handler($no, $str, $file, $line, $ctx) {
                        echo '<pre>';
                        echo 'no   : ' . $no . "\n";
                        echo 'str  : ' . $str . "\n";
                        echo 'file : ' . $file . "\n";
                        echo 'line : ' . $line . "\n";
                        echo 'ctx  : ';
                        print_r($ctx);
                        echo '</pre>';
                }

        }
?>

mmtache at yahoo dot com (2003-02-09 13:06:17)

The @ operator sets the error_reporting() value to 0.
This means you can use it with your own Error Handler too. for example:
function userErrorHandler($errno, $errmsg, $filename, $linenum, $vars) {
if (error_reporting())
echo $errmsg;
}
set_error_handler("userErrorHandler");
function test(){
trigger_error("Error Message", E_USER_WARNING);
}
@test(); // doesn't output anything

roy (2002-06-12 16:08:20)

Useful thing to note - if your error handler throws an error in itself, PHP is smart enough to use the deault error handler to handle it. This way, you don't end up in infinite flaming loops of death. This seems to be true, at least, in PHP 4.2.
('Course, there are ways to create your handler to handle even this situation, but it's probably best left this way for general purposes.)

publicmail at macfreek dot nl (2002-05-31 09:34:25)

Note: If you have a custom error handler and use assert(), you MUST set:
assert_options (ASSERT_WARNING, 0);
Otherwise, no output whatsoever will ever be shown if an assert fails.

ned at wgtech dot com (2002-03-01 11:52:40)

Just spent two days trying to find some method where a class can handle errors thrown at my convienience. After fighting with the pitfalls of this problem this is what I came up with. Hope it helps someone else save a little time. Its nice because all instances of this class will point to the same array that stores the errors.
class ApplicationObject {
var $error_List;

function ApplicationObject() {
set_error_handler('trapError');
$this->error_List = &trapError();
}
}
function &trapError() {
static $error_Vals = array();
if (func_num_args()==5) { // Error Event has been passed
$error_Vals[] = array( 'err_no' => func_get_arg(0), 'err_text' => func_get_arg(1), 'err_file' => func_get_arg(2), 'err_line' => func_get_arg(3), 'err_vars'=>func_get_arg(4));
}
if (func_num_args()==0) { // Setup call. Return reference
return $error_Vals;
}
}

j dot schriver at vindiou dot com (2000-09-27 20:50:11)

A quote from Zeev Suraski:

"The CVS version (scheduled for 4.0.2) of the function has been enhanced: 

- The error handler accepts three additional arguments - the filename in  which the error occured, the line number in which the error occured, and the context of the in which the error occured (a hash that points to the active symbol table at the place of the error)."

So, you can now do this:

function myErrorHandler ($errno, $errstr, $errfile, $errline, $errcontext) {...}

[Editor's Note:
The above phrase: "...the context of the in which the error occured (a hash that points to the active symbol table at the place of the error)." may be difficult for new programmers to understand.

What it means is that the last argument passed to your error handler (the $errcontext in the above example) will contain an array that contains the value of every variable that existed in the scope the error was triggered in.

Try the following example to see exactly how this works:

<?php
// Define a simple error handler
function error_handler ($level, $message, $file, $line, $context) {

    echo <<<_END_
An error of level $level was generated in file $file on line $line.
The error message was: $message
The following variables were set in the scope that the error occurred in:

<blockquote>
_END_;

    print_r ($context);
    print "\n</blockquote>";
}

// Set the error handler to the error_handler() function
set_error_handler ('error_handler');

// Make a function and trigger an error
function foo () {
    global $SERVER_ADMIN;
    $bar = 1;

    // Trigger the error in the local scope of the function    
    trigger_error ("Some error");
}

foo();

// Now trigger the error in global scope
trigger_error ("Some other error");
?>

-zak@php.net]