PHP表单提交数据如何接收_PHP表单数据处理方法完整指南

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $username = filter_input(INPUT_POST, "username", FILTER_SANITIZE_STRING);
  $email = filter_input(INPUT_POST, "email", FILTER_VALIDATE_EMAIL);

  if ($username && $email) {
    echo "Username: " . $username . "<br>";
    echo "Email: " . $email . "<br>";
  } else {
    echo "Invalid username or email.";
  }
}
?>

<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  Username: <input type="text" name="username"><br>
  Email: <input type="text" name="email"><br>
  <input type="submit">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $target_dir = "uploads/";
  $target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
  $uploadOk = 1;
  $imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));

  // Check if image file is a actual image or fake image
  if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
      echo "File is an image - " . $check["mime"] . ".";
      $uploadOk = 1;
    } else {
      echo "File is not an image.";
      $uploadOk = 0;
    }
  }

  // Check if file already exists
  if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
  }

  // Check file size
  if ($_FILES["fileToUpload"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
  }

  // Allow certain file formats
  if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
  && $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
  }

  // Check if $uploadOk is set to 0 by an error
  if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
  // if everything is ok, try to upload file
  } else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
      echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
    } else {
      echo "Sorry, there was an error uploading your file.";
    }
  }
}
?>

<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method="post" enctype="multipart/form-data">
  Select image to upload:
  <input type="file" name="fileToUpload" id="fileToUpload">
  <input type="submit" value="Upload Image" name="submit">
</form>

<?php
session_start();

function generate_csrf_token() {
  return bin2hex(random_bytes(32));
}

if (empty($_SESSION['csrf_token'])) {
  $_SESSION['csrf_token'] = generate_csrf_token();
}

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  if (!empty($_POST['csrf_token'])) {
    if (hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'])) {
      // Process the form
      echo "Form processed successfully!";
    } else {
      // CSRF attack detected
      echo "CSRF attack detected!";
    }
  } else {
    echo "CSRF token missing!";
  }
}
?>

<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  <input type="hidden" name="csrf_token" value="<?php echo $_SESSION['csrf_token']; ?>">
  Username: <input type="text" name="username"><br>
  Email: <input type="text" name="email"><br>
  <input type="submit">
</form>