Php Programming Code Examples
Php > Errors and Logging Code Examples
Error Handler
Error Handler
<?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] $errstr<br>\n";
break;
}
}
// function to test the error handling
function scale_by_log ($vect, $scale) {
if ( !is_numeric($scale) || $scale <= 0 )
trigger_error("log(x) for x <= 0 is undefined, you used: scale = $scale",
FATAL);
if (!is_array($vect)) {
trigger_error("Incorrect input vector, array of values expected", ERROR);
return null;
}
for ($i=0; $i<count($vect); $i ) {
if (!is_numeric($vect[$i]))
trigger_error("Value at position $i is not a number, using 0 (zero)",
WARNING);
$temp[$i] = log($scale) * $vect[$i];
}
return $temp;
}
// set to the user defined error handler
$old_error_handler = set_error_handler("myErrorHandler");
// trigger some errors, first define a mixed array with a non-numeric item
echo "vector a\n";
$a = array(2,3,"foo",5.5,43.3,21.11);
print_r($a);
// now generate second array, generating a warning
echo "----\nvector b - a warning (b = log(PI) * a)\n";
$b = scale_by_log($a, M_PI);
print_r($b);
// this is trouble, we pass a string instead of an array
echo "----\nvector c - an error\n";
$c = scale_by_log("not array",2.3);
var_dump($c);
// this is a critical error, log of zero or negative number is undefined
echo "----\nvector d - fatal error\n";
$d = scale_by_log($a, -2.5);
?>
