使用PHP警告尝试catch

你应该使用 libxml_use_internal_errors 为此。

本例改编自手册:

libxml_use_internal_errors(true);
$doc = new DOMDocument();
$res = $doc->loadHTMLFile($url); //this may fail and return FALSE!
foreach (libxml_get_errors() as $error) {
    // handle errors here
}
libxml_clear_errors();

此处不会发出PHP通知。

可能你在找这个

<?php
// error handler function
function myErrorHandler($errno, $errstr, $errfile, $errline)
{
    switch ($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;
    }

    /* Don't execute PHP internal error handler */
    return true;
}

// 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", 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;
}

// 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
echo "----\nvector b - a notice (b = log(PI) * a)\n";
/* Value at position $pos is not a number, using 0 (zero) */
$b = scale_by_log($a, M_PI);
print_r($b);

// this is trouble, we pass a string instead of an array
echo "----\nvector c - a warning\n";
/* Incorrect input vector, array of values expected */
$c = scale_by_log("not array", 2.3);
var_dump($c); // NULL

// this is a critical error, log of zero or negative number is undefined
echo "----\nvector d - fatal error\n";
/* log(x) for x <= 0 is undefined, you used: scale = $scale" */
$d = scale_by_log($a, -2.5);
var_dump($d); // Never reached
?>

这将使输出:

vector a
Array
(
    [0] => 2
    [1] => 3
    [2] => foo
    [3] => 5.5
    [4] => 43.3
    [5] => 21.11
)
----
vector b - a notice (b = log(PI) * a)
<b>My NOTICE</b> [1024] Value at position 2 is not a number, using 0 (zero)<br />
Array
(
    [0] => 2.2894597716988
    [1] => 3.4341896575482
    [2] => 0
    [3] => 6.2960143721717
    [4] => 49.566804057279
    [5] => 24.165247890281
)
----
vector c - a warning
<b>My WARNING</b> [512] Incorrect input vector, array of values expected<br />
NULL
----
vector d - fatal error
<b>My ERROR</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br />
  Fatal error on line 35 in file trigger_error.php, PHP 5.2.1 (FreeBSD)<br />
Aborting...<br />

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你可能会使用 custom error handler 但我不完全确定你得到的警告是否能得到处理。某些错误或警告将始终使用默认错误处理程序。但是试试看。

我刚在 http://bytes.com/topic/php/answers/6296-catch-warnings :

首先告诉PHP跟踪所有错误:

ini_set('track_errors', '1');

这会将所有错误消息(包括警告)放入变量中 $php_errormsg (见 http://www.php.net/manual/en/errorfunc.configuration.php#ini.track-errors )

然后,您可以捕获如下错误和警告:

if (!@copy('no_file', 'some_file')) {
  echo $php_errormsg, "\n";
}