Examples

- « Predefined Constants

- Error Handling Functions »

- PHP Manual
- Error Handling
- Examples

# 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 handlingerror_reporting(0);// user defined error handling functionfunction 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";?>