嗨，我是一名学生，对编程没有知识。如果登录的用户级别不是管理员，我只希望此代码能够重定向到我的用户index.php。目前，它进入我从网站复制的管理控制台，并且可以正常工作。这是我的示例代码：
<?php
// Initialize the session
session_start();
// Check if the user is already logged in, if yes then redirect him to welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
header("location: dashboard.php");
exit;
}
// Include config file
require_once "config.php";
// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = "";
// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){
// Check if username is empty
if(empty(trim($_POST["username"]))){
$username_err = "Please enter username.";
} else{
$username = trim($_POST["username"]);
}
// Check if password is empty
if(empty(trim($_POST["password"]))){
$password_err = "Please enter your password.";
} else{
$password = trim($_POST["password"]);
}
// Validate credentials
if(empty($username_err) && empty($password_err)){
// Prepare a select statement
$sql = "SELECT user_id, username, password FROM users WHERE username = ?";
if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "s", $param_username);
// Set parameters
$param_username = $username;
// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Store result
mysqli_stmt_store_result($stmt);
// Check if username exists, if yes then verify password
if(mysqli_stmt_num_rows($stmt) == 1){
// Bind result variables
mysqli_stmt_bind_result($stmt, $user_id, $username, $hashed_password);
if(mysqli_stmt_fetch($stmt)){
if(password_verify($password, $hashed_password)){
// Password is correct, so start a new session
session_start();
// Store data in session variables
$_SESSION["loggedin"] = true;
$_SESSION["user_id"] = $user_id;
$_SESSION["username"] = $username;
// Redirect user to welcome page
header("location: admin/dashboard.php");
} else{
// Display an error message if password is not valid
$password_err = "Invalid username or password. Please try again.";
}
}
} else{
// Display an error message if username doesn't exist
$password_err = "Invalid username or password. Please try again.";
}
} else{
echo "Oops! Something went wrong. Please try again later.";
}
}
// Close statement
mysqli_stmt_close($stmt);
}
// Close connection
mysqli_close($link);
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Login</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; background-image: url("bg.png");
background-color: #cccccc;}
.wrapper{ width: 400px; padding: 20px; margin: 0 auto; background-color: black; color: white; margin-top: 80px;}
.center { display: block; margin-left: auto; margin-right: auto; width: 60%;}
</style>
</head>
<body>
<div class="wrapper">
<br>
<img alt="logo" src="logo.png" class="center"/>
<h2 align="center">Secret Cafe Billing System</h2>
<p align="center">Please fill in your credentials to login.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username" class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<br>
<div align="center" class="form-group">
<input type="submit" class="btn btn-primary" value="Login">
</div>
<br><br>
</form>
</div>
</body>
</html>
如果输入了无效的凭据，我只是在用户名和密码上都编辑了错误消息，因为我们的顾问希望在两者上都出现一般性错误，并且不指定用户输入错误的凭据。对其进行了调整，幸运的是它起作用了。请帮忙。
答案 0 :(得分：1)
好的，我很想通了。这是我的答案。
<?php
// Initialize the session
session_start();
// Check if the user is already logged in, if yes then redirect him to welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
header("location: dashboard.php");
exit;
}
// Include config file
require_once "config.php";
// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = "";
// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){
// Check if username is empty
if(empty(trim($_POST["username"]))){
$username_err = "Please enter username.";
} else{
$username = trim($_POST["username"]);
}
// Check if password is empty
if(empty(trim($_POST["password"]))){
$password_err = "Please enter your password.";
} else{
$password = trim($_POST["password"]);
}
// Validate credentials
if(empty($username_err) && empty($password_err)){
// Prepare a select statement
$sql = "SELECT user_id, userlvl, username, password FROM users WHERE username = ?";
if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "s", $param_username);
// Set parameters
$param_username = $username;
// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Store result
mysqli_stmt_store_result($stmt);
// Check if username exists, if yes then verify password
if(mysqli_stmt_num_rows($stmt) == 1){
// Bind result variables
mysqli_stmt_bind_result($stmt, $user_id, $userlvl, $username, $hashed_password);
if(mysqli_stmt_fetch($stmt)){
if(password_verify($password, $hashed_password)){
// Password is correct, so start a new session
session_start();
if ($userlvl == 'Admin') {
// Store data in session variables
$_SESSION["loggedin"] = true;
$_SESSION["user_id"] = $user_id;
$_SESSION["username"] = $username;
// Redirect user to welcome page
header("location: admin/dashboard.php");
} else {
$_SESSION["loggedin"] = true;
$_SESSION["user_id"] = $user_id;
$_SESSION["username"] = $username;
// Redirect user to welcome page
header("location: admin/billing.php");
}
} else{
// Display an error message if password is not valid
$password_err = "Invalid username or password. Please try again.";
}
}
} else{
// Display an error message if username doesn't exist
$password_err = "Invalid username or password. Please try again.";
}
} else{
echo "Oops! Something went wrong. Please try again later.";
}
}
// Close statement
mysqli_stmt_close($stmt);
}
// Close connection
mysqli_close($link);
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Login</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; background-image: url("bg.png");
background-color: #cccccc;}
.wrapper{ width: 400px; padding: 20px; margin: 0 auto; background-color: black; color: white; margin-top: 80px;}
.center { display: block; margin-left: auto; margin-right: auto; width: 60%;}
</style>
</head>
<body>
<div class="wrapper">
<br>
<img alt="logo" src="logo.png" class="center"/>
<h2 align="center">Secret Cafe Billing System</h2>
<p align="center">Please fill in your credentials to login.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username" class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<br>
<div align="center" class="form-group">
<input type="submit" class="btn btn-primary" value="Login">
</div>
<br><br>
</form>
</div>
</body>
</html>