register_shutdown_function

Synopsis

Returns

NULL

Description

register_shutdown_function() allows the developer to register one or more functions to be called when the script ends. This function is very useful when you need to create automatic cleanup handlers.

The functions will be called in the order that the calls to register_shutdown_function() were made. If the script is terminated with a call to exit() or die() , the registered function(s) will not be called. Similarly, if one of the registered functions calls exit() or die() , the functions that were registered after it will not be called.

When using register_shutdown_function() , remember that no further output will be sent to the browser when the registered functions are called. This means that calls to print() or echo() will not display any data. Also, errors generated at runtime by the registered functions will not be sent to the browser.

Version

PHP Version: 3.0.4+, 4+

Example

// Create function that mails the server admin when a script has timed out
function alert_admin ()
{
    if (connection_timeout ())
        mail (
            $SERVER_ADMIN,
            "Script $SCRIPT_NAME timed out.",
            "$SCRIPT_NAME timed out - you may want to increase the max_execution_time value in your php.ini file.",
        );
}

// Set the function up to be called when the script ends.
register_shutdown_function ('alert_admin');

// Lots of other code
// ...