PHP Filter 函数

// 验证整数
$int = '123';
if (filter_var($int, FILTER_VALIDATE_INT)) {
    echo "$int 是有效的整数\n";
} else {
    echo "$int 不是有效的整数\n";
}

// 验证邮箱
$email = 'john@example.com';
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
    echo "$email 是有效的邮箱地址\n";
} else {
    echo "$email 不是有效的邮箱地址\n";
}

// 验证URL
$url = 'https://www.example.com';
if (filter_var($url, FILTER_VALIDATE_URL)) {
    echo "$url 是有效的URL\n";
} else {
    echo "$url 不是有效的URL\n";
}

// 验证IP地址
$ip = '192.168.1.1';
if (filter_var($ip, FILTER_VALIDATE_IP)) {
    echo "$ip 是有效的IP地址\n";
} else {
    echo "$ip 不是有效的IP地址\n";
}

// 验证布尔值
$bool = 'true';
$result = filter_var($bool, FILTER_VALIDATE_BOOLEAN);
echo "布尔验证结果: ";
var_dump($result);

// 清理字符串中的HTML标签
$string = "<script>alert('xss')</script>Hello <b>World</b>";
$clean = filter_var($string, FILTER_SANITIZE_STRING);
echo "清理后的字符串: " . $clean . "\n";

// 清理邮箱地址
$email = "john.(doe)@exa//mple.com";
$clean_email = filter_var($email, FILTER_SANITIZE_EMAIL);
echo "清理后的邮箱: " . $clean_email . "\n";

// 清理URL
$url = "http://www.example.com/<script>alert(1)</script>";
$clean_url = filter_var($url, FILTER_SANITIZE_URL);
echo "清理后的URL: " . $clean_url . "\n";

// 清理整数
$number = "123abc456";
$clean_number = filter_var($number, FILTER_SANITIZE_NUMBER_INT);
echo "清理后的整数: " . $clean_number . "\n";

// HTML特殊字符转义
$html = '<p>Test "quotes" & specials</p>';
$escaped = filter_var($html, FILTER_SANITIZE_FULL_SPECIAL_CHARS);
echo "转义后的HTML: " . $escaped . "\n";

// 使用 filter_input() 获取和过滤GET参数
$name = filter_input(INPUT_GET, 'name', FILTER_SANITIZE_STRING);
$age = filter_input(INPUT_GET, 'age', FILTER_VALIDATE_INT);
$email = filter_input(INPUT_GET, 'email', FILTER_VALIDATE_EMAIL);

echo "姓名: " . ($name ?: '未提供') . "\n";
echo "年龄: " . ($age ?: '无效或未提供') . "\n";
echo "邮箱: " . ($email ?: '无效或未提供') . "\n";

// 使用 filter_input_array() 批量处理
$filters = [
    'username' => FILTER_SANITIZE_STRING,
    'email'    => FILTER_VALIDATE_EMAIL,
    'age'      => ['filter' => FILTER_VALIDATE_INT, 'options' => ['min_range' => 1, 'max_range' => 120]],
    'website'  => FILTER_VALIDATE_URL,
    'score'    => ['filter' => FILTER_VALIDATE_FLOAT, 'options' => ['min_range' => 0, 'max_range' => 100]]
];

$input = filter_input_array(INPUT_GET, $filters);

echo "批量验证结果:\n";
print_r($input);