How to use PHP to verify username and password (code)-PHP Tutorial-php.cn

How to use PHP to verify username and password (code)

不言

Release： 2023-04-03 11:30:01

Original

2464 people have browsed it

The content shared with you in this article is about using PHP to verify user names and passwords. The content is of great reference value and I hope it can help friends in need.

Login page login.html

<html>  
<head>用户登录</head>  
<form name="LoginForm" method="post" action="login.php" onSubmit="return InputCheck(this)">  
<p>  
<label for="username" class="label">用户名:</label>  
<input id="username" name="username" type="text" class="input" />  
<p/>  
<p>  
<label for="password" class="label">密 码:</label>  
<input id="password" name="password" type="password" class="input" />  
<p/>  
<p>  
<input type="submit" name="submit" value="  确 定  " class="left" />  
</p>  
</form>  
</html>

Copy after login

Login verification, logout login login.php

<?php 
//登录  
if(!isset($_POST[&#39;submit&#39;])){  
    exit(&#39;非法访问!&#39;);  
}  
$username = htmlspecialchars($_POST[&#39;username&#39;]);  
$password = MD5($_POST[&#39;password&#39;]);  
   
//包含数据库连接文件  
include(&#39;conn.php&#39;);  
//检测用户名及密码是否正确  
$check_query = mysql_query("select userid from user_list where username=&#39;$username&#39; and password=&#39;$password&#39; limit 1");  
if($result = mysql_fetch_array($check_query)){  
    //登录成功  
    session_start();  
    $_SESSION[&#39;username&#39;] = $username;  
    $_SESSION[&#39;userid&#39;] = $result[&#39;userid&#39;];  
    echo $username,&#39; 欢迎你！进入 <a href="my.php">用户中心</a><br />&#39;;  
    echo &#39;点击此处 <a href="login.php?action=logout">注销</a> 登录！<br />&#39;;  
    exit;  
} else {  
    exit(&#39;登录失败！点击此处 <a href="javascript:history.back(-1);">返回</a> 重试&#39;);  
}  
   
   
   
//注销登录  
if($_GET[&#39;action&#39;] == "logout"){  
    unset($_SESSION[&#39;userid&#39;]);  
    unset($_SESSION[&#39;username&#39;]);  
    echo &#39;注销登录成功！点击此处 <a href="login.html">登录</a>&#39;;  
    exit;  
}  
   
?>

Copy after login

Login monitoring my.php

<?php  
session_start();  
   
//检测是否登录，若没登录则转向登录界面  
if(!isset($_SESSION[&#39;userid&#39;])){  
    header("Location:login.html");  
    exit();  
}  
//包含数据库连接文件  
include(&#39;conn.php&#39;);  
$userid = $_SESSION[&#39;userid&#39;];  
$username = $_SESSION[&#39;username&#39;];  
$user_query = mysql_query("select * from user_list where userid = &#39;$userid&#39; limit 1");  
$row = mysql_fetch_array($user_query);  
echo &#39;用户信息：<br />&#39;;  
echo &#39;用户ID：&#39;,$userid,&#39;<br />&#39;;  
echo &#39;用户名：&#39;,$username,&#39;<br />&#39;;  
echo &#39;<a href="login.php?action=logout">注销</a> 登录<br />&#39;;  
?>

Copy after login

Connect to the database conn.php

<?php
 $conn = mysql_connect("127.0.0.1","root","") or die("数据库链接错误".mysql_error());  
 mysql_select_db("info_db",$conn) or die("数据库访问错误".mysql_error());  
 mysql_query("set names gb2312");  
?>

Copy after login

Related recommendations:

How to use PHP to implement single sign-on Method analysis

Use php to implement simple background registration and login (with code)

The above is the detailed content of How to use PHP to verify username and password (code). For more information, please follow other related articles on the PHP Chinese website!