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set_error_handler

(PHP 4 >= 4.0.1)

set_error_handler --  Sets a user-defined error handler function.

Description

string set_error_handler (string error_handler)

Sets a user function (error_handler) to handle errors in a script. Returns the previously defined error handler (if any), or false on error. 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())

The user function needs to accept 2 parameters: the error code, and a string describing the error. From PHP 4.0.2, an additional 3 optional parameters are supplied: the filename in which the error occured, the line number in which the error occured, and the context in which the error occured (an array that points to the active symbol table at the point the error occurred).

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

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

<?php

// redefine the user error constants - PHP 4 only
define (FATAL,E_USER_ERROR);
define (ERROR,E_USER_WARNING);
define (WARNING,E_USER_NOTICE);

// set the error reporting level for this script
error_reporting (FATAL | ERROR | WARNING);

// error handler function
function myErrorHandler ($errno, $errstr, $errfile, $errline) {
  switch ($errno) {
  case FATAL:
    echo "<b>FATAL</b> [$errno] $errstr<br>\n";
    echo "  Fatal error in line ".$errline." of file ".$errfile;
    echo ", PHP ".PHP_VERSION." (".PHP_OS.")<br>\n";
    echo "Aborting...<br>\n";
    exit -1;
    break;
  case ERROR:
    echo "<b>ERROR</b> [$errno] $errstr<br>\n";
    break;
  case WARNING:
    echo "<b>WARNING</b> [$errno] $errstr<br>\n";
    break;
    default:
    echo "Unkown error type: [$errno] $errstr<b