php restore_error_handler() function and restore_exception_handler() function

restore_error_handler — Restore the previous error handling Function

Description

bool restore_error_handler ( void )

Change the error using set_error_handler() After handling the function, this function can be used to restore the previous error handler (either a built-in or a user-defined function).

Return value

This function always returns TRUE.

restore_error_handler() example

If unserialize() causes an error, the original error handling function will be restored.

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

$serialized  =  &#39;foo&#39; ;
set_error_handler ( &#39;unserialize_handler&#39; );
$original  =  unserialize ( $serialized );
restore_error_handler ();
?>

The above routine will output:

Invalid serialized value.

restore_exception_handler - Restore the previously defined Exception handling function.

Description

bool restore_exception_handler ( void )

After using set_exception_handler() to change the exception handling function, this function can be used to restore the previous exception handler (can be built-in or is a user-defined function).

Return value

This function always returns TRUE.

restore_exception_handler() function example

<?php
     function  exception_handler_1 ( Exception $e )
    {
        echo  &#39;[&#39;  .  FUNCTION  .  &#39;] &#39;  .  $e -> getMessage ();
    }

    function  exception_handler_2 ( Exception $e )
    {
        echo  &#39;[&#39;  .  FUNCTION  .  &#39;] &#39;  .  $e -> getMessage ();
    }

     set_exception_handler ( &#39;exception_handler_1&#39; );
     set_exception_handler ( &#39;exception_handler_2&#39; );

     restore_exception_handler ();

    throw new  Exception ( &#39;This triggers the first exception handler...&#39; );
?>

The above routine will output:

[exception_handler_1] This triggers the first exception handler...

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