PHP 학습 경험: 안전한 코드 작성 방법

function validatePhoneNumber($phoneNumber) {
   $pattern = "/^[1-9]d{10}$/";
   if (preg_match($pattern, $phoneNumber)) {
      // 验证通过，继续处理逻辑
   } else {
      // 验证失败，给出错误提示
   }
}

function filterOutput($string) {
   return htmlspecialchars($string, ENT_QUOTES, 'UTF-8');
}

// 输出到前端页面
echo filterOutput($userInput);

$pdo = new PDO("mysql:host=localhost;dbname=myDatabase", "username", "password");

$statement = $pdo->prepare("SELECT * FROM users WHERE username = :username AND password = :password");
$statement->bindParam(':username', $username);
$statement->bindParam(':password', $password);

$statement->execute();

$result = $statement->fetch(PDO::FETCH_ASSOC);

if ($_FILES["file"]["size"] > 2000000) {
   echo "文件过大";
   exit;
}

$allowedFileType = array("pdf", "doc", "jpg", "png");
$allowedFileSize = 500000;

$uploadedFileType = strtolower(pathinfo($_FILES["file"]["name"], PATHINFO_EXTENSION));
if (!in_array($uploadedFileType, $allowedFileType)) {
   echo "不支持的文件类型";
   exit;
}

if ($_FILES["file"]["size"] > $allowedFileSize) {
   echo "文件过大";
   exit;
}

// 保存上传文件
move_uploaded_file($_FILES["file"]["tmp_name"], "uploads/" . $_FILES["file"]["name"]);