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Correction status：qualified
Teacher's comments：
Collection
Collection
<?php
$dbc=mysqli_connect('127.0.0.1','root','5201314','php');
if(mysqli_connect_error()){
die('连接失败'.mysqli_connect_error());
}点击 "运行实例" 按钮查看在线实例
<?php
function redirect_user($page='index.php'){
$url='http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']);
$url=trim($url,'/\\');
$url.='/'.$page;
header('Location:'.$url);
exit();
}
function check_login($dbc,$email='',$password){
$errors=[];
if(empty($email)){
$errors[]='邮箱不能为空';
}else{
$e=mysqli_real_escape_string($dbc,trim($email));
}
if(empty($password)){
$errors[]='密码不能为空';
}else{
$p=mysqli_real_escape_string($dbc,trim($password));
}
if(empty($errors)){
$sql="select `user_id`,`user_name` from `user` where `email`='$e' and `password`=sha1('$p')";
$res=mysqli_query($dbc,$sql);
if(mysqli_num_rows($res) == 1){
$row=mysqli_fetch_array($res,MYSQLI_ASSOC);
return [true,$row];
}else{
$errors[]='邮箱或密码错误，请重新输入';
}
}
return [false,$errors];
}点击 "运行实例" 按钮查看在线实例
<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <h2>公共头部</h2>
点击 "运行实例" 按钮查看在线实例
<?php
include 'public/header.php';
echo '<h2>首页</h2>';
if(isset($_COOKIE['id'])&&basename($_SERVER['PHP_SELF']) !='logout.php'){
echo '<a href="logout.php">退出</a>';
}else{
echo '<a href="login.php">登录</a>';
}
include 'public/footer.php';
?>点击 "运行实例" 按钮查看在线实例
<?php include 'public/header.php'; ?> <h2>用户登录</h2> <form action="logincheck.php" method="post"> <p> <label for="email">邮箱：</label> <input type="email" name="email" id="email" value=""> </p> <p> <label for="password">密码：</label> <input type="password" name="password" id="password" value=""> </p> <p> <button type="submit" name="submit" id="submit">登录</button> </p> </form> <?php include 'public/footer.php'; ?>
点击 "运行实例" 按钮查看在线实例
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
require 'public/connect.php';
require 'public/function.php';
list($check,$data)=check_login($dbc,$_POST['email'],$_POST['password']);
if($check){
setcookie('user_id',$data['user_id']);
setcookie('user_name',$data['user_name']);
redirect_user('logined.php');
}else{
$errors=$data;
}
}点击 "运行实例" 按钮查看在线实例
<?php
if(!isset($_COOKIE['user_id'])){
require 'public/function.php';
redirect_user();
}
include 'public/header.php';
echo <<< "WELCOME"
<h2>登录成功</h2>
<p>欢迎您：亲爱的{$_COOKIE['user_name']}</p>
<p><a href="logout.php">退出</a></p>
WELCOME;
include 'public/footer.php';点击 "运行实例" 按钮查看在线实例
<?php
if (!isset($_COOKIE['user_id'])){
require 'public/function.php';
redirect_user();
}else{
setcookie('user_id','',time()-3600);
setcookie('user_name','',time()-3600);
}
echo <<<"WELCOME"
<h2>退出成功</h2>
<p><a href="login.php">登录</a></p>
WELCOME;
include 'public/footer.php';点击 "运行实例" 按钮查看在线实例
session
<?php
$dbc=mysqli_connect('127.0.0.1','root','5201314','php');
if(mysqli_connect_error()){
die('连接失败'.mysqli_connect_error());
}点击 "运行实例" 按钮查看在线实例
<?php
function check_login($dbc,$email='',$password){
$errors=[];
if(empty($email)){
$errors[]='邮箱不能为空';
}else{
$e=mysqli_real_escape_string($dbc,trim($email));
}
if(empty($password)){
$errors[]='密码不能为空';
}else{
$p=mysqli_real_escape_string($dbc,trim($password));
}
if(empty($errors)){
$sql="select `user_id`,`user_name` from `user` where `email`='$e' and `password`=sha1('$p')";
$res=mysqli_query($dbc,$sql);
if(mysqli_num_rows($res) == 1){
$row=mysqli_fetch_array($res,MYSQLI_ASSOC);
return [true,$row];
}else{
$errors[]='邮箱或密码错误，请重新输入';
}
}
return [false,$errors];
}
function redirect_user($page='index.php'){
$url='http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']);
$url=trim($url,'/\\');
$url.='/'.$page;
header('Location:'.$url);
exit();
}点击 "运行实例" 按钮查看在线实例
<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <h2>公共头部</h2>
点击 "运行实例" 按钮查看在线实例
<?php
//启动会话
session_start();
//导入页面的公共头部
include 'public/header.php';
echo '<h2>首页</h2>';
//判断用户是否登录?
if(isset($_SESSION['id'])&&basename($_SERVER['PHP_SELF']) !='logout.php'){
echo '<a href="logout.php">退出</a>';
}else{
echo '<a href="login.php">登录</a>';
}
//导入页面的公共底部
include 'public/footer.php';
?>点击 "运行实例" 按钮查看在线实例
<?php include 'public/header.php'; ?> <h2>用户登录</h2> <form action="logincheck.php" method="post"> <p> <label for="email">邮箱：</label> <input type="email" name="email" id="email" value=""> </p> <p> <label for="password">密码：</label> <input type="password" name="password" id="password" value=""> </p> <p> <button type="submit" name="submit" id="submit">登录</button> </p> </form> <?php include 'public/footer.php'; ?>
点击 "运行实例" 按钮查看在线实例
<?php
//启动会话
session_start();
if($_SERVER['REQUEST_METHOD']=='POST'){
//加载函数库
require 'public/connect.php';
//连接数据库
require 'public/function.php';
//验证登录
list($check,$data)=check_login($dbc,$_POST['email'],$_POST['password']);
//检测是否验证通过
if($check) {
//设置session
$_SESSION['user_id']=$data['user_id'];
$_SESSION['user_name']=$data['user_name'];
//跳转
redirect_user('logined.php');
}else{
$errors=$data;
}
//关闭
mysqli_close($dbc);
}点击 "运行实例" 按钮查看在线实例
<?php
//启动会话
session_start();
//判断用户是否登录?
if(!isset($_SESSION['user_id'])){
require 'public/function.php';
redirect_user();
}
//导入页面的公共头部
include 'public/header.php';
echo <<< "WELCOME"
<h2>登录成功</h2>
<p>欢迎您：亲爱的{$_SESSION['user_name']}</p>
<p><a href="logout.php">退出</a></p>
WELCOME;
//导入页面的公共底部
include 'public/footer.php';点击 "运行实例" 按钮查看在线实例
<?php
session_start();
//判断用户是否登录?
if (!isset($_SESSION['user_id'])){
require 'public/function.php';
redirect_user();
}else{
session_destroy();
setcookie('PHPSESSID','',time()-3600);
}
echo <<<"WELCOME"
<h2>退出成功</h2>
<p><a href="login.php">登录</a></p>
WELCOME;
//导入页面的公共底部
include 'public/footer.php';点击 "运行实例" 按钮查看在线实例
cookie与session优缺点
1、cookie数据存放在kehu的浏览器上，session数据放在服务器上。
2、cookie不是很安全，别人可以分析存放在本地的cookie并进行cookie欺骗，考虑到安全应当使用session。
3、session会在一定时间内保存在服务器上。当访问增多，会比较占用你服务器的性能，考虑到减轻服务器性能方面，应当使用cookie。
4、单个cookie保存的数据不能超过4K，很多浏览器都限制一个站点最多保存20个cookie。
5、可以考虑将登陆信息等重要信息存放为session，其他信息如果需要保留，可以放在cookie中。