Archive for category useful PHP scripts

Initially create a configuration script to mention the database host, username, password to access the database and database name.

Which may look like the below php script loadconfig.php

<?php

// the mySQL host
$dbHost="ur db hostname";

// the name of the database to connect to
$dbName="ur database name";

// username with database access
$uName="ur database username";

// password of \uName
$passwd="ur database password";

?>

Then create a login script to access the index page only when authenticated.

create a login.php script which may look like

<?php
session_start();
if (!isset($_SESSION["lastVisited"] )) {
$_SESSION["lastVisited"] = $_SERVER["HTTP_REFERER"];
$tmp = split("\/",$_SESSION["lastVisited"]);
if (end($tmp) == "login.php") {
$_SESSION["lastVisited"] = "index.php";
}
}
$username = $_REQUEST['username'];
$password = $_REQUEST['password'];
try {
include("loadconf.php");
} catch (Exception $e) {
header("Location: Error.php");
}
mysql_connect($dbHost,$uName,$passwd);
@mysql_select_db($dbName);

if (!isset($_REQUEST['username'])) {
$title="Logging In";
$loggingIn = true;
?>
<div style="display: table; width: 100%;">
<div style="width: 60%;display: table-cell; vertical-align: middle;  padding-right: 100px;">
<p>Enter your username and password in the boxes on the right and click "Login" to continue.</p>
<?if (isset($_REQUEST["e"])) {?><p style="color: red;">Bad username or password.</p><?}?>
</div>
<div style="display: table-cell; vertical-align: middle;">
<form action="login.php" method="post">
<p>Username<br />
<input name="username" /></p>
<p>Password<br />
<input name="password" type="password" /></p>
<p><input type="submit" value="Login" />
<input type="reset" value="Clear" /></p>
</form>
</div>
</div>
<?
} else {
mysql_connect($dbHost,$uName,$passwd);
@mysql_select_db($dbName);
$query = "SELECT * from users where uName = '".$_REQUEST["username"]."' and pwd = '".md5($_REQUEST["password"])."'";
$result = mysql_query($query);
if (mysql_numrows($result)) {
$_SESSION["loggedIn"] = true;
$_SESSION["userName"] = $_REQUEST["username"];
header("Location: ".$_SESSION["lastVisited"]);
} else {
header("Location: login.php?e=error");
}
mysql_close();
}
?> 

In the above login script it is required to make an table named users containing atleast two coloums with uName(username), pwd(password). You can do this using the below mysql script
database.sql or you can enter the below two commands if you have access to the database.

use $dbName
CREATE TABLE users (uID INT NOT NULL AUTO_INCREMENT PRIMARY KEY, uName VARCHAR(30), pwd VARCHAR(32));

Finally we need a logout script to end the session. You may wonder why you need a logout script but it is very important for a security reason as anyone having the cookies or session key can login for ever. It is very good practice to logout every time you login. I know number of cases where people lost their orkut, gmail and other accounts for not logging out of their system :). So here is the logout.php script for the above login script.

<?php
        session_start();
        unset($_SESSION["loggedIn"]);
        header("Location: ".$_SERVER["HTTP_REFERER"]);
?> 

So you learnt how to write a login, logout script and also to create a simple database with uId, uName, pwd to authenticate users.

To check whether the script is running or not, insert an entry in your users table by using the below sql command.

use $dbName
INSERT INTO users values (1,'admin','21232f297a57a5a743894a0e4a801fc3'); 

The above password is in a md5 hash for “admin”. so try to login with

username : admin
password : admin

Hope you found this useful.