error checking php code example
Example: php error handling
<?php
function myErrorHandler($errno, $errstr, $errfile, $errline)
{
if (!(error_reporting() & $errno)) {
return false;
}
switch ($errno) {
case E_USER_ERROR:
echo "<b>My ERROR</b> [$errno] $errstr<br />\n";
echo " Fatal error on line $errline in file $errfile";
echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
echo "Aborting...<br />\n";
exit(1);
break;
case E_USER_WARNING:
echo "<b>My WARNING</b> [$errno] $errstr<br />\n";
break;
case E_USER_NOTICE:
echo "<b>My NOTICE</b> [$errno] $errstr<br />\n";
break;
default:
echo "Unknown error type: [$errno] $errstr<br />\n";
break;
}
return true;
}
function scale_by_log($vect, $scale)
{
if (!is_numeric($scale) || $scale <= 0) {
trigger_error("log(x) for x <= 0 is undefined, you used: scale = $scale", E_USER_ERROR);
}
if (!is_array($vect)) {
trigger_error("Incorrect input vector, array of values expected", E_USER_WARNING);
return null;
}
$temp = array();
foreach($vect as $pos => $value) {
if (!is_numeric($value)) {
trigger_error("Value at position $pos is not a number, using 0 (zero)", E_USER_NOTICE);
$value = 0;
}
$temp[$pos] = log($scale) * $value;
}
return $temp;
}
$old_error_handler = set_error_handler("myErrorHandler");
echo "vector a\n";
$a = array(2, 3, "foo", 5.5, 43.3, 21.11);
print_r($a);
echo "----\nvector b - a notice (b = log(PI) * a)\n";
$b = scale_by_log($a, M_PI);
print_r($b);
echo "----\nvector c - a warning\n";
$c = scale_by_log("not array", 2.3);
var_dump($c);
echo "----\nvector d - fatal error\n";
$d = scale_by_log($a, -2.5);
var_dump($d);
?>