php教程

restore_error_handler

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

restore_error_handler还原之前的错误处理函数

说明

restore_error_handler ( void ) : bool

在使用 set_error_handler() 改变错误处理函数之后,此函数可以 用于还原之前的错误处理程序(可以是内置的或者也可以是用户所定义的函数)。

返回值

该函数总是返回 TRUE

范例

Example #1 restore_error_handler() 范例

如果是 unserialize() 导致了一个错误,接下来 会恢复原来的错误处理函数。

<?php
function unserialize_handler($errno$errstr)
{
    echo 
"Invalid serialized value.\n";
}

$serialized 'foo';
set_error_handler('unserialize_handler');
$original unserialize($serialized);
restore_error_handler();
?>

以上例程会输出:

Invalid serialized value.

参见

User Contributed Notes

masterada at gmail dot com 27-Mar-2017 01:45
Calling restore_error_handler from within an error handler might result in unexpected behaviour:

<?php
error_reporting
(0);

set_error_handler('handleError1');
trigger_error('1-stack:h1');

set_error_handler('handleError2');
trigger_error('2-stack:h1,h2');

trigger_error('6-stack:h1,h2');
trigger_error('7-stack:h1,h2');

function
handleError1($code, $message, $file = '', $line = 0, $context = array())
{
    echo 
__METHOD__ . ' ' . $message . PHP_EOL;
}

function
handleError2($code, $message, $file = '', $line = 0, $context = array())
{
   
trigger_error('3-DEFAULT'); // This will use the php's default error handler

   
echo  __METHOD__ . ' ' . $message . PHP_EOL;

   
set_error_handler('handleError3');
   
trigger_error('4-stack:h1,h2,h3');

   
restore_error_handler(); // This will restore the handleError1 instead of the default error handler
   
trigger_error('5-DEFAULT');
}

function
handleError3($code, $message, $file = '', $line = 0, $context = array())
{
    echo 
__METHOD__ . ' ' . $message . PHP_EOL;
}

?>

The above code will output:

handleError1 1-stack:h1
handleError2 2-stack:h1,h2
handleError3 4-stack:h1,h2,h3
handleError1 5-DEFAULT
handleError1 6-stack:h1,h2
handleError1 7-stack:h1,h2

The following workaround can be used:

<?php

error_reporting
(0);

set_error_handler('handleError1');
trigger_error('1-stack:h1');

set_error_handler('handleError2');
trigger_error('2-stack:h1,h2');

trigger_error('6-stack:h1,h2');
trigger_error('7-stack:h1,h2');

function
handleError1($code, $message, $file = '', $line = 0, $context = array())
{
    echo
__METHOD__ . ' ' . $message . PHP_EOL;
}

function
handleError2($code, $message, $file = '', $line = 0, $context = [])
{
   
restore_error_handler(); // This will restore the previous error handler
   
set_error_handler('count', 0); // Set a dummy method for error handling, it will never be called because $error_type = 0
   
try
    {
       
trigger_error('3-DEFAULT');

        echo
__METHOD__ . ' ' . $message . PHP_EOL;

       
set_error_handler('handleError3');
       
trigger_error('4-stack:h1,h2,h3');

       
restore_error_handler();
       
trigger_error('5-DEFAULT');
    }
    finally
    {
       
restore_error_handler(); // Restore the previous error handler
       
set_error_handler('handleError2'); // Set the current error handler again
   
}
}

function
handleError3($code, $message, $file = '', $line = 0, $context = [])
{
    echo
__METHOD__ . ' ' . $message . PHP_EOL;
}
?>

which will output:

handleError1 1-stack:h1
handleError2 2-stack:h1,h2
handleError3 4-stack:h1,h2,h3
handleError2 6-stack:h1,h2
handleError3 4-stack:h1,h2,h3
handleError2 7-stack:h1,h2
handleError3 4-stack:h1,h2,h3
TiMESPLiNTER 27-Apr-2015 10:39
Works also for restoring nested error handlers:

<?php

error_reporting
(E_ALL);

echo
'<pre>';

set_error_handler(function($errno, $errstr, $errfile, $errline, array $errcontext) {
    echo
'ErrorHandler 1: ' , $errstr , PHP_EOL;
});

trigger_error('Error 1');

set_error_handler(function($errno, $errstr, $errfile, $errline, array $errcontext) {
    echo
'ErrorHandler 2: ' , $errstr , PHP_EOL;
});

trigger_error('Error 2');

restore_error_handler();

trigger_error('Error 3');

restore_error_handler();

trigger_error('Error 4');

?>
edgarinvillegas at hotmail dot com 28-Mar-2008 08:21
Isolde is kind of wrong. The error handlers are stacked with set_error_handler(), and popped with restore_error_handler(). Here i put an example:

<?php
    mysql_connect
("inexistent"); //Generate an error. The actual error handler is set by default

   
function foo1() {echo "<br>Error foo1<br>";}
    function
foo2() {echo "<br>Error foo2<br>";}
    function
foo3() {echo "<br>Error foo3<br>";}
   
   
set_error_handler("foo1");    //current error handler: foo1
   
set_error_handler("foo2");    //current error handler: foo2
   
set_error_handler("foo3");    //current error handler: foo3
   
   
mysql_connect("inexistent");   
   
restore_error_handler();        //now, current error handler: foo2
   
mysql_connect("inexistent");    
   
restore_error_handler();        //now, current error handler: foo1
   
mysql_connect("inexistent");
   
restore_error_handler();        //now current error handler: default handler
   
mysql_connect("inexistent");
   
restore_error_handler();        //now current error handler: default handler (The stack can't pop more)
?>
lsole at maresme dot net 14-Mar-2004 11:57
As the docs say, restore_error_handler() revert to the *previous error handler*... even if it is the same. A bug made me set twice my custom error handler and later when I was calling restore_error_handler() to restore the built-in handler nothing seemed to happen... this puzzled me for a while!

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