set_error_handler

(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)

set_error_handler Задаёт пользовательский обработчик ошибок

Описание

set_error_handler(?callable $callback, int $error_levels = E_ALL): ?callable

Задаёт пользовательскую функцию (callback), как обработчик ошибок в скрипте.

Функция может быть использована для определения пользовательских обработчиков ошибок во время выполнения, например, в приложениях, которые должны выполнять очистку файлов/данных в случае возникновения критической ошибки или при инициировании ошибки в ответ на определённые условия (используя функцию trigger_error()).

Важно помнить, что стандартный обработчик ошибок PHP не будет обрабатывать никакие типы ошибок, определённые в error_levels, пока callback-функция не вернёт false. Пользовательский обработчик будет вызываться в случае возникновения любой ошибки, независимо от настроек, заданных функцией error_reporting.

Также обратите внимание, что обработчик обязан при необходимости остановить выполнение скрипта, вызвав функцию exit(). Если происходит возврат из обработчика ошибок, управление передаётся следующему выражению, стоящему за тем, что вызвало ошибку.

Ошибки следующих типов не могут быть обработаны пользователем: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING независимо от того, где они были сгенерированы и большинство ошибок E_STRICT, произошедших в файле, где вызвана функция set_error_handler().

Если ошибки возникают до запуска скрипта (например, пока файл загружается), пользовательский обработчик не будет вызываться, если на этот момент он ещё не зарегистрирован.

Список параметров

callback

Если передано значение null, обработчик сбрасывается в состояние по умолчанию. В противном случае обработчик представляет собой callback-функцию со следующей сигнатурой:

handler(
    int $errno,
    string $errstr,
    string $errfile = ?,
    int $errline = ?,
    array $errcontext = ?
): bool
errno
В первый аргумент errno будет передан уровень ошибки в виде целого числа.
errstr
Во второй аргумент errstr будет передано сообщение об ошибке в виде строки.
errfile
Если функция обратного вызова принимает третий параметр errfile, то в него будет передано имя файла, в котором произошла ошибка, в виде строки.
errline
Если функция обратного вызова принимает четвёртый параметр errline, то в него будет передан номер строки, в которой произошла ошибка, в виде целого числа.
errcontext
Если функция обратного вызова принимает пятый параметр errcontext, то в него будет передан массив указателей на активную таблицу символов в точке, где произошла ошибка. Другими словами, errcontext будет содержать массив всех переменных, существующих в области видимости, где произошла ошибка. Пользовательские обработчики ошибок не должны изменять этот контекст.
Внимание

Этот параметр объявлен УСТАРЕВШИМ начиная с PHP 7.2.0 и был УДАЛЁН в PHP 8.0.0. Если в вашей функции этот параметр используется и для него не задано значение по умолчанию, то при вызове функции обработчика будет выдана ошибка "too few arguments".

Если функция возвращает false, управление передаётся встроенному обработчику ошибок.

error_levels

Может использоваться для задания маски, в соответствии с которой будет вызываться callback, по аналогии с ini-настройкой error_reporting, которая отвечает за то, какие ошибки будут показаны в отчёте. Без этой маски callback будет вызываться для обработки всех происходящих ошибок, вне зависимости от настроек в error_reporting.

Возвращаемые значения

Возвращает ранее определённый обработчик ошибок (если есть) Если на данный момент используется встроенный обработчик, функция вернёт null. Если предыдущий определённый обработчик является методом класса, функция вернёт массив, содержащий имя класса и имя метода.

Список изменений

Версия Описание
8.0.0 Параметр errcontext был удалён и больше не передаётся в пользовательскую функцию обработки ошибок.
7.2.0 Параметр errcontext объявлен устаревшим. Теперь при его использовании будет вызываться ошибка уровня E_DEPRECATED.

Примеры

Пример #1 Обработка ошибок с помощью функций set_error_handler() и trigger_error()

Пример ниже демонстрирует обработку внутренних исключений путём вызова ошибок разных типов и их обработки пользовательской функцией:

<?php
// функция обработки ошибок
function myErrorHandler($errno, $errstr, $errfile, $errline)
{
if (!(
error_reporting() & $errno)) {
// Этот код ошибки не включён в error_reporting,
// так что пусть обрабатываются стандартным обработчиком ошибок PHP
return false;
}

// может потребоваться экранирование $errstr:
$errstr = htmlspecialchars($errstr);

switch (
$errno) {
case
E_USER_ERROR:
echo
"<b>Пользовательская ОШИБКА</b> [$errno] $errstr<br />\n";
echo
" Фатальная ошибка в строке $errline файла $errfile";
echo
", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
echo
"Завершение работы...<br />\n";
exit(
1);

case
E_USER_WARNING:
echo
"<b>Пользовательское ПРЕДУПРЕЖДЕНИЕ</b> [$errno] $errstr<br />\n";
break;

case
E_USER_NOTICE:
echo
"<b>Пользовательское УВЕДОМЛЕНИЕ</b> [$errno] $errstr<br />\n";
break;

default:
echo
"Неизвестная ошибка: [$errno] $errstr<br />\n";
break;
}

/* Не запускаем внутренний обработчик ошибок PHP */
return true;
}

// функция для тестирования обработчика ошибок
function scale_by_log($vect, $scale)
{
if (!
is_numeric($scale) || $scale <= 0) {
trigger_error("log(x) для x <= 0 не определён, вы используете: scale = $scale", E_USER_ERROR);
}

if (!
is_array($vect)) {
trigger_error("Некорректный входной вектор, пропущен массив значений", E_USER_WARNING);
return
null;
}

$temp = array();
foreach(
$vect as $pos => $value) {
if (!
is_numeric($value)) {
trigger_error("Значение на позиции $pos не является числом, будет использован 0 (ноль)", E_USER_NOTICE);
$value = 0;
}
$temp[$pos] = log($scale) * $value;
}

return
$temp;
}

// переключаемся на пользовательский обработчик
$old_error_handler = set_error_handler("myErrorHandler");

// вызовем несколько ошибок, во-первых, определим массив с нечисловым элементом
echo "vector a\n";
$a = array(2, 3, "foo", 5.5, 43.3, 21.11);
print_r($a);

// теперь создадим ещё один массив
echo "----\nvector b - a notice (b = log(PI) * a)\n";
/* Значение на позиции $pos не является числом, будет использован 0 (ноль)*/
$b = scale_by_log($a, M_PI);
print_r($b);

// проблема, мы передаём строку вместо массива
echo "----\nvector c - a warning\n";
/* Некорректный входной вектор, пропущен массив значений */
$c = scale_by_log("not array", 2.3);
var_dump($c); // NULL

// критическая ошибка, логарифм от неположительного числа не определён
echo "----\nvector d - fatal error\n";
/* log(x) для x <= 0 не определён, вы используете: scale = $scale */
$d = scale_by_log($a, -2.5);
var_dump($d); // До сюда не дойдём никогда
?>

Вывод приведённого примера будет похож на:

vector a
Array
(
    [0] => 2
    [1] => 3
    [2] => foo
    [3] => 5.5
    [4] => 43.3
    [5] => 21.11
)
----
vector b - a notice (b = log(PI) * a)
<b>Пользовательское УВЕДОМЛЕНИЕ</b> [1024]  Значение на позиции 2 не является числом, будет использован 0 (ноль)<br />
Array
(
    [0] => 2.2894597716988
    [1] => 3.4341896575482
    [2] => 0
    [3] => 6.2960143721717
    [4] => 49.566804057279
    [5] => 24.165247890281
)
----
vector c - a warning
<b>Пользовательское ПРЕДУПРЕЖДЕНИЕ</b> [512] Некорректный входной вектор, пропущен массив значений<br />
NULL
----
vector d - fatal error
<b>Пользовательская ОШИБКА</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br />
  Фатальная ошибка в строке 35 файла trigger_error.php, PHP 5.2.1 (FreeBSD)<br />
Завершение работы...<br />

Смотрите также

add a note add a note

User Contributed Notes 34 notes

up
75
Philip
11 years ago
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 );
up
45
elad dot yosifon at gmail dot com
11 years ago
<?php
/**
* throw exceptions based on E_* error types
*/
set_error_handler(function ($err_severity, $err_msg, $err_file, $err_line, array $err_context)
{
   
// error was suppressed with the @-operator
   
if (0 === error_reporting()) { return false;}
    switch(
$err_severity)
    {
        case
E_ERROR:               throw new ErrorException            ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_WARNING:             throw new WarningException          ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_PARSE:               throw new ParseException            ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_NOTICE:              throw new NoticeException           ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_CORE_ERROR:          throw new CoreErrorException        ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_CORE_WARNING:        throw new CoreWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_COMPILE_ERROR:       throw new CompileErrorException     ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_COMPILE_WARNING:     throw new CoreWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_USER_ERROR:          throw new UserErrorException        ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_USER_WARNING:        throw new UserWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_USER_NOTICE:         throw new UserNoticeException       ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_STRICT:              throw new StrictException           ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_RECOVERABLE_ERROR:   throw new RecoverableErrorException ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_DEPRECATED:          throw new DeprecatedException       ($err_msg, 0, $err_severity, $err_file, $err_line);
        case
E_USER_DEPRECATED:     throw new UserDeprecatedException   ($err_msg, 0, $err_severity, $err_file, $err_line);
    }
});

class
WarningException              extends ErrorException {}
class
ParseException                extends ErrorException {}
class
NoticeException               extends ErrorException {}
class
CoreErrorException            extends ErrorException {}
class
CoreWarningException          extends ErrorException {}
class
CompileErrorException         extends ErrorException {}
class
CompileWarningException       extends ErrorException {}
class
UserErrorException            extends ErrorException {}
class
UserWarningException          extends ErrorException {}
class
UserNoticeException           extends ErrorException {}
class
StrictException               extends ErrorException {}
class
RecoverableErrorException     extends ErrorException {}
class
DeprecatedException           extends ErrorException {}
class
UserDeprecatedException       extends ErrorException {}
up
7
steve962 at gmail dot com
6 years ago
Be careful when using the return value to this function.   Because it returns the old handler, you may be tempted to do something like:

<?php
function do_something()
    {
   
$old = set_error_handler(“my_error_handler”);
   
// Do something you want handled by my_error_handler
   
set_error_handler($old);
    }
?>

This will work, but it will bite you because each time you do this, it will cause a memory leak as the old error handler is put on a stack for the restore_error_handler() function to use.

So always restore the old error handler using that function instead:

<?php
function do_something()
    {
   
set_error_handler(“my_error_handler”);
   
// Do something you want handled by my_error_handler
   
restore_error_handler();
    }
?>
up
18
aditycse at gmail dot com
8 years ago
<?php
/**
* Used for logging all php notices,warings and etc in a file when error reporting
* is set and display_errors is off
* @uses used in prod env for logging all type of error of php code in a file for further debugging
* and code performance
* @author Aditya Mehrotra<aditycse@gmail.com>
*/
error_reporting(E_ALL);
ini_set("display_errors", "off");
define('ERROR_LOG_FILE', '/var/www/error.log');

/**
* Custom error handler
* @param integer $code
* @param string $description
* @param string $file
* @param interger $line
* @param mixed $context
* @return boolean
*/
function handleError($code, $description, $file = null, $line = null, $context = null) {
   
$displayErrors = ini_get("display_errors");
   
$displayErrors = strtolower($displayErrors);
    if (
error_reporting() === 0 || $displayErrors === "on") {
        return
false;
    }
    list(
$error, $log) = mapErrorCode($code);
   
$data = array(
       
'level' => $log,
       
'code' => $code,
       
'error' => $error,
       
'description' => $description,
       
'file' => $file,
       
'line' => $line,
       
'context' => $context,
       
'path' => $file,
       
'message' => $error . ' (' . $code . '): ' . $description . ' in [' . $file . ', line ' . $line . ']'
   
);
    return
fileLog($data);
}

/**
* This method is used to write data in file
* @param mixed $logData
* @param string $fileName
* @return boolean
*/
function fileLog($logData, $fileName = ERROR_LOG_FILE) {
   
$fh = fopen($fileName, 'a+');
    if (
is_array($logData)) {
       
$logData = print_r($logData, 1);
    }
   
$status = fwrite($fh, $logData);
   
fclose($fh);
    return (
$status) ? true : false;
}

/**
* Map an error code into an Error word, and log location.
*
* @param int $code Error code to map
* @return array Array of error word, and log location.
*/
function mapErrorCode($code) {
   
$error = $log = null;
    switch (
$code) {
        case
E_PARSE:
        case
E_ERROR:
        case
E_CORE_ERROR:
        case
E_COMPILE_ERROR:
        case
E_USER_ERROR:
           
$error = 'Fatal Error';
           
$log = LOG_ERR;
            break;
        case
E_WARNING:
        case
E_USER_WARNING:
        case
E_COMPILE_WARNING:
        case
E_RECOVERABLE_ERROR:
           
$error = 'Warning';
           
$log = LOG_WARNING;
            break;
        case
E_NOTICE:
        case
E_USER_NOTICE:
           
$error = 'Notice';
           
$log = LOG_NOTICE;
            break;
        case
E_STRICT:
           
$error = 'Strict';
           
$log = LOG_NOTICE;
            break;
        case
E_DEPRECATED:
        case
E_USER_DEPRECATED:
           
$error = 'Deprecated';
           
$log = LOG_NOTICE;
            break;
        default :
            break;
    }
    return array(
$error, $log);
}

//calling custom error handler
set_error_handler("handleError");

print_r($arra); //undefined variable
print_r($dssdfdfgg); //undefined variable
include_once 'file.php'; //No such file or directory
?>
up
6
nizamgok at gmail dot com
15 years ago
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.
up
9
dannykopping at gmail dot com
10 years ago
Keep in mind that, when attempting to set a statically-defined error handler on a namespaced class in PHP >= 5.3, you need to use the class namespace:

<?php
set_error_handler
('\\My\\Namespace\\Bob::errorHandler');
?>
up
7
Jacob Slomp
11 years ago
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");
?>
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webmaster at paramiliar dot com
16 years ago
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__);
   

?>
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silkensedai at online dot fr
17 years ago
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
?>
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wfinn at riverbed dot com
16 years ago
"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();

?>
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kalle at meizo dot com
15 years ago
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).
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2
francois vespa
14 years ago
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
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5
dorphalsig at NOSPAMgmail dot com
13 years ago
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 )
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2
Marcelius
15 years ago
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.
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3
roy
22 years ago
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.)
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2
Anonymous
18 years ago
To honor the value of PHP's error_reporting() function, use:

<?
 
if( ($level & error_reporting()) == 0 ) return;
?>
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7
phpmanual at NO_SPHAMnetebb dot com
21 years ago
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.
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3
jtrick77 at gmail dot com
11 years ago
For anyone interested in the actual translated error codes and their meanings:

1    E_ERROR (integer)     Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted.    
2    E_WARNING (integer)     Run-time warnings (non-fatal errors). Execution of the script is not halted.    
4    E_PARSE (integer)     Compile-time parse errors. Parse errors should only be generated by the parser.    
8    E_NOTICE (integer)     Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.    
16    E_CORE_ERROR (integer)     Fatal errors that occur during PHP's initial startup. This is like an E_ERROR, except it is generated by the core of PHP.    
32    E_CORE_WARNING (integer)     Warnings (non-fatal errors) that occur during PHP's initial startup. This is like an E_WARNING, except it is generated by the core of PHP.    
64    E_COMPILE_ERROR (integer)     Fatal compile-time errors. This is like an E_ERROR, except it is generated by the Zend Scripting Engine.    
128    E_COMPILE_WARNING (integer)     Compile-time warnings (non-fatal errors). This is like an E_WARNING, except it is generated by the Zend Scripting Engine.    
256    E_USER_ERROR (integer)     User-generated error message. This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error().    
512    E_USER_WARNING (integer)     User-generated warning message. This is like an E_WARNING, except it is generated in PHP code by using the PHP function trigger_error().    
1024    E_USER_NOTICE (integer)     User-generated notice message. This is like an E_NOTICE, except it is generated in PHP code by using the PHP function trigger_error().    
2048    E_STRICT (integer)     Enable to have PHP suggest changes to your code which will ensure the best interoperability and forward compatibility of your code.    Since PHP 5 but not included in E_ALL until PHP 5.4.0
4096    E_RECOVERABLE_ERROR (integer)     Catchable fatal error. It indicates that a probably dangerous error occurred, but did not leave the Engine in an unstable state. If the error is not caught by a user defined handle (see also set_error_handler()), the application aborts as it was an E_ERROR.    Since PHP 5.2.0
8192    E_DEPRECATED (integer)     Run-time notices. Enable this to receive warnings about code that will not work in future versions.    Since PHP 5.3.0
16384    E_USER_DEPRECATED (integer)     User-generated warning message. This is like an E_DEPRECATED, except it is generated in PHP code by using the PHP function trigger_error().    Since PHP 5.3.0
32767    E_ALL (integer)     All errors and warnings, as supported, except of level E_STRICT prior to PHP 5.4.0.     32767 in PHP 5.4.x, 30719 in PHP 5.3.x, 6143 in PHP 5.2.x, 2047 previously

(Copied from http://php.net/manual/en/errorfunc.constants.php)
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3
nicolas dot grekas+php at gmail dot com
11 years ago
If you want to be sure that the native PHP error handler is called without resetting the handler stack (as set_error_handler(null) does), you can simply call set_error_handler with $error_types set to zero. This can be especially use full in conjunction with e.g. error_get_last():

<?php

// var_dump or anything else, as this will never be called because of the 0
set_error_handler('var_dump', 0);
@
$undef_var;
restore_error_handler();

// error_get_last() is now in a well known state:
// Undefined variable: undef_var

... // Do something

$e = error_get_last();

...

?>
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2
phil at propcom dot co dot uk
11 years ago
It is important to note that the registered SPL autoloader will NOT be called if an E_STRICT error triggers the error handler which, in turn, tries to use classes which are not yet loaded.

In this instance, you should manually load classes required by the error handler.
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2
stepheneliotdewey at GmailDotCom
17 years ago
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]]] )
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2
Steffen Staehle
19 years ago
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");

?>
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Anonymous
20 years ago
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>!!'
?>
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2
periklis
14 years ago
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    
   
}
}
?>
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2
Klauss
7 years ago
Hi everyone. I don't know if it is an old behavior of previous versions, but currently you can set exception and error handlers as private or protected methos, if, only if, you call `set_exception_handler()` or `set_error_handler()` within a context that can access the method.

Example:
    <?PHP
        $Handler
= new class ()
        {
            public function
__construct ()
            {
               
set_error_handler([&$this, 'HandleError']);
               
set_exception_handler([&$this, 'HandleException']);
            }
            protected function
HandleError ( $Code, $Message, $File = null, $Line = 0, $Context = [] )
            {
               
// Handle error here.
           
}
            private function
HandleException ( $Exception )
            {
               
// Handle exception here.
           
}
        }
   
?>

NOTE: these methods must match the callbacks parameters signatures.
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0
RGraph
1 year ago
A simple error handler that makes errors far more visible:

    //
    // Set the error handler to one that prints out more
    // visible errors
    //
    set_error_handler(function ($errno, $errstr)
    {
        $str = '<div style="margin: 20px; background-color: #fdd; border: 3px solid red; padding: 10px; border-radius: 15px; line-height: 25px"><b>Error: </b>%s (error level: %s)</div>';
       
        printf($str, $errstr, $errno);
    });
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a dot ross at amdev dot eu
6 years ago
I'm missing a way to chain error handlers. It's not something offered by set_error_handler. You have to jump through some hoops to get it to work, but it *is* quite possible, by making use of the return value of the function. Here's an example:

<?
$previous
= set_error_handler(function ($errno, $errstr, $errfile, $errline, $errcontext) use (&$previous) {
   
/* Your custom error handling code here. */

    // If another error handler was defined, call it.
   
if ($previous) {
        return
$previous($errno, $errstr, $errfile, $errline, $errcontext);
    } else {
       
// Use the standard PHP error handler.
       
return false;
    }
});
?>
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kaioker
3 years ago
super simple error code to human readable conversion:

function prettycode($code){
    return $code == 0 ? "FATAL" : array_search($code, get_defined_constants(true)['Core']);
}
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0
Alex M
3 years ago
If you are new to programming and you would like to know how to add a combination of those error reporting values to .htaccess file. Here's a small guide.

With PHP function error_reporting we can add together option with bitwise add operator | . But we can't use those constants in htaccess file and in my case I have no idea how to add bitwise number.

So, solution can be casting selected options to int:

echo (int)(E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR) ;
->263

Then you can use 263 in .htaccess

php_value error_reporting 263

In my case I needed those errors to be displayed for my debugging server. But the combination can be different from mine.
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0
David Spector
4 years ago
The PHP manual is not very clear about how to handle @ operator error messages.

Here is working code:

    // Do nothing if @ operator
    $errLevel=error_reporting(E_ALL);
    if ($errLevel===0)
        return true; // ignore @ prefixed expression errors
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chris at ocproducts dot com
8 years ago
Note that error handlers don't run recursively. If you have an error while an error handler is running (in the error handler itself or code called from it) then you won't get the error handler called again.

This has subtle ramifications for $php_errormsg. If you are relying on your error handler to suppress certain kinds of error message from going into $php_errormsg (via return true; because error_reporting doesn't affect $php_errormsg setting) then this will not work for any code called within that error handler.
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0
mmtache at yahoo dot com
21 years ago
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
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-1
ash
17 years ago
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);
    }
}

?>
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-1
devermin at ti0n dot net
14 years ago
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";
}

?>
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