Register Register Member Login Member Login Member Login Forgot Password ??
PHP , ASP , ASP.NET, VB.NET, C#, Java , jQuery , Android , iOS , Windows Phone
 

Registered : 109,036

HOME > PHP Manual > set_error_handler - Sets a user-defined error handler function





ลองใช้ค้นหาข้อมูล


   
Bookmark.

set_error_handler

(PHP 4 >= 4.0.1, PHP 5)

set_error_handlerSets a user-defined error handler function

Description

mixed set_error_handler ( callback $error_handler [, int $error_types ] )

Sets a user function (error_handler ) to handle errors in a script.

This function can be used for defining your own way of handling errors during runtime, for example in applications in which you need to do cleanup of data/files when a critical error happens, or when you need to trigger an error under certain conditions (using trigger_error()).

It is important to remember that the standard PHP error handler is completely bypassed. error_reporting() settings will have no effect and your error handler will be called regardless - however you are still able to read the current value of error_reporting and act appropriately. Of particular note is that this value will be 0 if the statement that caused the error was prepended by the @ error-control operator.

Also note that it is your responsibility to die() if necessary. If the error-handler function returns, script execution will continue with the next statement after the one that caused an error.

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.

If errors occur before the script is executed (e.g. on file uploads) the custom error handler cannot be called since it is not registered at that time.

Parameters

error_handler

The user function needs to accept two parameters: the error code, and a string describing the error. Then there are three optional parameters that may be supplied: the filename in which the error occurred, the line number in which the error occurred, and the context in which the error occurred (an array that points to the active symbol table at the point the error occurred). The function can be shown as:

handler ( int $errno , string $errstr [, string $errfile [, int $errline [, array $errcontext ]]] )
errno
The first parameter, errno , contains the level of the error raised, as an integer.
errstr
The second parameter, errstr , contains the error message, as a string.
errfile
The third parameter is optional, errfile , which contains the filename that the error was raised in, as a string.
errline
The fourth parameter is optional, errline , which contains the line number the error was raised at, as an integer.
errcontext
The fifth parameter is optional, errcontext , which is an array that points to the active symbol table at the point the error occurred. In other words, 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.

If the function returns FALSE then the normal error handler continues.

error_types

Can be used to mask the triggering of the error_handler function just like the error_reporting ini setting controls which errors are shown. Without this mask set the error_handler will be called for every error regardless to the setting of the error_reporting setting.

Return Values

Returns a string containing the previously defined error handler (if any), or NULL on error. If the previous handler was a class method, this function will return an indexed array with the class and the method name.

ChangeLog

Version Description
5.2.0 The error handler must return FALSE to populate $php_errormsg.
5.0.0 The error_types parameter was introduced.
4.3.0 Instead of a function name, an array containing an object reference and a method name can also be supplied as the error_handler .
4.0.2 Three optional parameters for the error_handler user function was introduced. These are the filename, the line number, and the context.

Examples

Example #1 Error handling with set_error_handler() and trigger_error()

The example below shows the handling of internal exceptions by triggering errors and handling them with a user defined function:

<?php
// error handler function
function myErrorHandler($errno$errstr$errfile$errline)
{
    switch (
$errno) {
    case 
E_USER_ERROR:
        echo 
"<b>My ERROR</b> [$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:
        echo 
"<b>My WARNING</b> [$errno] $errstr<br />\n";
        break;

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

    default:
        echo 
"Unknown error type: [$errno] $errstr<br />\n";
        break;
    }

    
/* Don't execute PHP internal error handler */
    
return true;
}

// function to test the error handling
function scale_by_log($vect$scale)
{
    if (!
is_numeric($scale) || $scale <= 0) {
        
trigger_error("log(x) for x <= 0 is undefined, you used: scale = $scale"E_USER_ERROR);
    }

    if (!
is_array($vect)) {
        
trigger_error("Incorrect input vector, array of values expected"E_USER_WARNING);
        return 
null;
    }

    
$temp = array();
    foreach(
$vect as $pos => $value) {
        if (!
is_numeric($value)) {
            
trigger_error("Value at position $pos is not a number, using 0 (zero)"E_USER_NOTICE);
            
$value 0;
        }
        
$temp[$pos] = log($scale) * $value;
    }

    return 
$temp;
}

// set to the user defined error handler
$old_error_handler set_error_handler("myErrorHandler");

// trigger some errors, first define a mixed array with a non-numeric item
echo "vector a\n";
$a = array(23"foo"5.543.321.11);
print_r($a);

// now generate second array
echo "----\nvector b - a notice (b = log(PI) * a)\n";
/* Value at position $pos is not a number, using 0 (zero) */
$b scale_by_log($aM_PI);
print_r($b);

// this is trouble, we pass a string instead of an array
echo "----\nvector c - a warning\n";
/* Incorrect input vector, array of values expected */
$c scale_by_log("not array"2.3);
var_dump($c); // NULL

// this is a critical error, log of zero or negative number is undefined
echo "----\nvector d - fatal error\n";
/* log(x) for x <= 0 is undefined, you used: scale = $scale" */
$d scale_by_log($a, -2.5);
var_dump($d); // Never reached
?>

The above example will output something similar to:

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>My NOTICE</b> [1024] Value at position 2 is not a number, using 0 (zero)<br />
Array
(
    [0] => 2.2894597716988
    [1] => 3.4341896575482
    [2] => 0
    [3] => 6.2960143721717
    [4] => 49.566804057279
    [5] => 24.165247890281
)
----
vector c - a warning
<b>My WARNING</b> [512] Incorrect input vector, array of values expected<br />
NULL
----
vector d - fatal error
<b>My ERROR</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br />
  Fatal error on line 35 in file trigger_error.php, PHP 5.2.1 (FreeBSD)<br />
Aborting...<br />



ThaiCreate.Com Forum


Comunity Forum Free Web Script
Jobs Freelance Free Uploads
Free Web Hosting Free Tools

สอน PHP ผ่าน Youtube ฟรี
สอน Android การเขียนโปรแกรม Android
สอน Windows Phone การเขียนโปรแกรม Windows Phone 7 และ 8
สอน iOS การเขียนโปรแกรม iPhone, iPad
สอน Java การเขียนโปรแกรม ภาษา Java
สอน Java GUI การเขียนโปรแกรม ภาษา Java GUI
สอน JSP การเขียนโปรแกรม ภาษา Java
สอน jQuery การเขียนโปรแกรม ภาษา jQuery
สอน .Net การเขียนโปรแกรม ภาษา .Net
Free Tutorial
สอน Google Maps Api
สอน Windows Service
สอน Entity Framework
สอน Android
สอน Java เขียน Java
Java GUI Swing
สอน JSP (Web App)
iOS (iPhone,iPad)
Windows Phone
Windows Azure
Windows Store
Laravel Framework
Yii PHP Framework
สอน jQuery
สอน jQuery กับ Ajax
สอน PHP OOP (Vdo)
Ajax Tutorials
SQL Tutorials
สอน SQL (Part 2)
JavaScript Tutorial
Javascript Tips
VBScript Tutorial
VBScript Validation
Microsoft Access
MySQL Tutorials
-- Stored Procedure
MariaDB Database
SQL Server Tutorial
SQL Server 2005
SQL Server 2008
SQL Server 2012
-- Stored Procedure
Oracle Database
-- Stored Procedure
SVN (Subversion)
แนวทางการทำ SEO
ปรับแต่งเว็บให้โหลดเร็ว


Hit Link
   







Load balance : Server 00
ThaiCreate.Com Logo
© www.ThaiCreate.Com. 2003-2024 All Rights Reserved.
ไทยครีเอทบริการ จัดทำดูแลแก้ไข Web Application ทุกรูปแบบ (PHP, .Net Application, VB.Net, C#)
[Conditions Privacy Statement] ติดต่อโฆษณา 081-987-6107 อัตราราคา คลิกที่นี่