How to use PHP functions to implement session management and security verification of user login and logout?-PHP Tutorial-php.cn

How to use PHP functions to implement session management and security verification of user login and logout?

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Release： 2023-07-26 16:58:02

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How to use PHP functions to implement session management and security verification of user login and logout?

In Web development, session management and security verification of user login and logout are very important links. As a powerful server-side scripting language, PHP provides a wealth of functions to implement this process. This article will introduce how to use PHP functions to implement session management and security verification of user login and logout.

First, we need to create a login page to allow users to enter their username and password to log in.

<?php
session_start();
if($_SERVER['REQUEST_METHOD'] == 'POST'){
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 验证用户名和密码
    if($username === 'admin' && $password === 'password'){
        $_SESSION['username'] = $username;
        header('Location: welcome.php');
        exit();
    }else{
        echo '用户名或密码错误';
    }
}
?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>用户登录</title>
</head>
<body>
<form method="post" action="">
    <label for="username">用户名</label>
    <input type="text" name="username" id="username" required>
    <br>
    <label for="password">密码</label>
    <input type="password" name="password" id="password" required>
    <br>
    <input type="submit" value="登录">
</form>
</body>
</html>

Copy after login

The session_start() function is used in the above code to open the session. $_SERVER['REQUEST_METHOD'] == 'POST' determines whether the request method is POST. If so, obtain the username and password submitted by the user. , and verify. After the verification is passed, the user name is saved in the session and jumps to the welcome page through header('Location: welcome.php').

In the welcome page, we can determine whether the user has logged in based on the user name in the session.

<?php
session_start();
if(empty($_SESSION['username'])){
    header('Location: login.php');
    exit();
}
?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>欢迎</title>
</head>
<body>
<h1>欢迎回来，<?php echo $_SESSION['username']; ?></h1>
<a href="logout.php">注销</a>
</body>
</html>

Copy after login

empty($_SESSION['username']) is used in the above code to determine whether the user name in the session is empty. If it is empty, it means that the user is not logged in. Through header('Location: login. php') jump to the login page. If the user name in the session is not empty, it means that the user has logged in, a welcome message is displayed, and the logout function is provided.

Next, we need to create a logout page for users to log out of the currently logged in session.

<?php
session_start();
session_destroy();
header('Location: login.php');
exit();
?>

Copy after login

The session_destroy() function is used in the above code to destroy the current session and jump to the login page through header('Location: login.php').

Through the above code examples, we can implement session management and security verification of user login and logout. When the user logs in successfully, the user's information is saved in the session and can be used in other pages. When the user logs out, destroy the session and jump back to the login page. This ensures the security of users' login information and provides a simple and effective session management and security verification mechanism.

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