Predefined Constants
<?php
switch ($errno) {
/* Fatal run-time errors.
* These indicate errors that can not be recovered from, such as a memory allocation problem.
* Execution of the script is halted.
*/
case E_ERROR:
break;
/* Run-time warnings (non-fatal errors).
* Execution of the script is not halted.
*/
case E_WARNING:
break;
/* Compile-time parse errors.
* Parse errors should only be generated by the parser.
*/
case E_PARSE:
break;
/* Run-time notices.
* Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.
*/
case E_NOTICE:
break;
/* Fatal errors that occur during PHP's initial startup.
* This is like an E_ERROR, except it is generated by the core of PHP.
*/
case E_CORE_ERROR:
break;
/* Warnings (non-fatal errors) that occur during PHP's initial startup.
* This is like an E_WARNING, except it is generated by the core of PHP.
*/
case E_CORE_WARNING:
break;
/* Fatal compile-time errors.
* This is like an E_ERROR, except it is generated by the Zend Scripting Engine.
*/
case E_COMPILE_ERROR:
break;
/* Compile-time warnings (non-fatal errors).
* This is like an E_WARNING, except it is generated by the Zend Scripting Engine.
*/
case E_COMPILE_WARNING:
break;
/* User-generated error message.
* This is like an E_ERROR, except it is generated in PHP code by
* using the PHP function trigger_error().
*/
case E_USER_ERROR:
break;
/* User-generated warning message.
* This is like an E_WARNING, except it is generated in PHP code by
* using the PHP function trigger_error().
*/
case E_USER_WARNING:
break;
/* User-generated notice message.
* This is like an E_NOTICE, except it is generated in PHP code by
* using the PHP function trigger_error().
*/
case E_USER_NOTICE:
break;
/* Enable to have PHP suggest changes to your code which will ensure the
* best interoperability and forward compatibility of your code.
*/
case E_STRICT:
break;
/* Catchable fatal error. It indicates that a probably dangerous
* error occured, but did not leave the Engine in an unstable state.
* If the error is not caught by a user defined handle (see also
* set_error_handler()), the application aborts as it was an E_ERROR.
*/
case E_RECOVERABLE_ERROR:
break;
/* Run-time notices. Enable this to receive warnings about code that
* will not work in future versions.
*/
case E_DEPRECATED:
break;
/* User-generated warning message. This is like an E_DEPRECATED, except it
* is generated in PHP code by using the PHP function trigger_error().
*/
case E_USER_DEPRECATED:
break;
?>
Examples
Below we can see an example of using the error handling capabilities in PHP. We define an error handling function which logs the information into a file (using an XML format), and e-mails the developer if a critical error in the logic happens.
Example #1 Using error handling in a script
<?php
// we will do our own error handling
error_reporting(0);
// user defined error handling function
function userErrorHandler($errno, $errmsg, $filename, $linenum, $vars)
{
// timestamp for the error entry
$dt = date("Y-m-d H:i:s (T)");
// define an assoc array of error string
// in reality the only entries we should
// consider are E_WARNING, E_NOTICE, E_USER_ERROR,
// E_USER_WARNING and E_USER_NOTICE
$errortype = array (
E_ERROR => 'Error',
E_WARNING => 'Warning',
E_PARSE => 'Parsing Error',
E_NOTICE => 'Notice',
E_CORE_ERROR => 'Core Error',
E_CORE_WARNING => 'Core Warning',
E_COMPILE_ERROR => 'Compile Error',
E_COMPILE_WARNING => 'Compile Warning',
E_USER_ERROR => 'User Error',
E_USER_WARNING => 'User Warning',
E_USER_NOTICE => 'User Notice',
E_STRICT => 'Runtime Notice',
E_RECOVERABLE_ERROR => 'Catchable Fatal Error'
);
// set of errors for which a var trace will be saved
$user_errors = array(E_USER_ERROR, E_USER_WARNING, E_USER_NOTICE);
$err = "<errorentry>\n";
$err .= "\t<datetime>" . $dt . "</datetime>\n";
$err .= "\t<errornum>" . $errno . "</errornum>\n";
$err .= "\t<errortype>" . $errortype[$errno] . "</errortype>\n";
$err .= "\t<errormsg>" . $errmsg . "</errormsg>\n";
$err .= "\t<scriptname>" . $filename . "</scriptname>\n";
$err .= "\t<scriptlinenum>" . $linenum . "</scriptlinenum>\n";
if (in_array($errno, $user_errors)) {
$err .= "\t<vartrace>" . wddx_serialize_value($vars, "Variables") . "</vartrace>\n";
}
$err .= "</errorentry>\n\n";
// for testing
// echo $err;
// save to the error log, and e-mail me if there is a critical user error
error_log($err, 3, "/usr/local/php4/error.log");
if ($errno == E_USER_ERROR) {
mail("phpdev@example.com", "Critical User Error", $err);
}
}
function distance($vect1, $vect2)
{
if (!is_array($vect1) || !is_array($vect2)) {
trigger_error("Incorrect parameters, arrays expected", E_USER_ERROR);
return NULL;
}
if (count($vect1) != count($vect2)) {
trigger_error("Vectors need to be of the same size", E_USER_ERROR);
return NULL;
}
for ($i=0; $i<count($vect1); $i++) {
$c1 = $vect1[$i]; $c2 = $vect2[$i];
$d = 0.0;
if (!is_numeric($c1)) {
trigger_error("Coordinate $i in vector 1 is not a number, using zero",
E_USER_WARNING);
$c1 = 0.0;
}
if (!is_numeric($c2)) {
trigger_error("Coordinate $i in vector 2 is not a number, using zero",
E_USER_WARNING);
$c2 = 0.0;
}
$d += $c2*$c2 - $c1*$c1;
}
return sqrt($d);
}
$old_error_handler = set_error_handler("userErrorHandler");
// undefined constant, generates a warning
$t = I_AM_NOT_DEFINED;
// define some "vectors"
$a = array(2, 3, "foo");
$b = array(5.5, 4.3, -1.6);
$c = array(1, -3);
// generate a user error
$t1 = distance($c, $b) . "\n";
// generate another user error
$t2 = distance($b, "i am not an array") . "\n";
// generate a warning
$t3 = distance($a, $b) . "\n";
?>
add a note
User Contributed Notes
Examples
Henry Paradiz
13-Apr-2009 06:55