网站安全之用户输入过滤filter_var()

过滤函数

filter_var()

示例

$int = "123abc";  
$filtered = filter_var($int, FILTER_VALIDATE_INT);  
if ($filtered !== false) {  
    echo $filtered; // 输出: 123  
} else {  
    echo "Not an integer";  
}

$email = "test@example.com";  
$filtered = filter_var($email, FILTER_VALIDATE_EMAIL);  
if ($filtered !== false) {  
    echo $filtered; // 输出: test@example.com  
} else {  
    echo "Not a valid email";  
}

$email = "<script>bad@email.com</script>";  
$filtered = filter_var($email, FILTER_SANITIZE_EMAIL);  
echo $filtered; // 输出: bad@email.com

$url = "http://example.com/path?query=string#fragment"; 
$filtered_url = filter_var($url, FILTER_VALIDATE_URL);  
if ($filtered_url !== false) {  
    echo "URL is valid: " . $filtered_url;  
} else {  
    echo "URL is not valid";  
}