问题
i am creating a simple login and logout script using php and mysql but when i try to enter the login.php or the index file i get an error message that say : **The page isn't redirecting properly Firefox has detected that the server is redirecting the request for this address in a way that will never complete.
This problem can sometimes be caused by disabling or refusing to accept cookies.** i do not know how to solve or what is the error if anyone help me i will be appreciate
index.php
<?php
require_once('connect.php');
ob_start();
session_start();
//checked wether the user is loged in or not
$user = $_SESSION['username'];
if(!isset($_SESSION['username']))
{
$user = $_SESSION['username'];
header("Location: index.php");
exit();
}
else
{
header("Location: home.php");
}
// login script
if(isset($_POST['username'])&& isset($_POST['password']))
{
$user_login = preg_replace('#[^A-Za-z0-9]#i', '', $_POST['username']);
$user_password = preg_replace('#[^A-Za-z0-9]#i', '', $_POST['password']);
$md5password = md5($user_password);
$sql = mysql_query("SELECT id FROM members WHERE username = '".$user_login."' AND password = '".$user_password."'") or die ("could not select from database");
$userCount = mysql_num_rows($sql);
if($userCount ==1)
{
while($row = mysql_fetch_array($sql))
{
$id = $row['id'];
}
$_SESSION['id'] = $id;
$_SESSION['username'] = $user_login;
$_SESSION['password'] = $user_password;
header("Location: index.php");
exit();
}
else
{
echo "that info is incorrect";
exit();
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<form action="login.php" method="post">
<input name="username" type="text" value="username" size="32" />
<input name="pass" type="password" value="password" size="32" />
<input name="login" type="submit" value="login" />
</form>
</body>
</html>
<?php ob_end_flush(); ?>
home.php
<?php
//home.php
session_start();
$user = $_SESSION['username'];
if(!isset($_SESSION['username']))
{
header("Location: index.php");
exit();
}
else
{
echo "hi $user you are loged in //Welcome to our website <a href=\"logout.php\">Logout</a>";
}
?>
logout.php
<?php
session_start();
session_destroy();
header("Location: index.php");
?>
回答1:
In index.php you need to put this if condition on top after 'session_start();'
if($_SESSION['username'])
{
header("Location: home.php");
exit();
}
In while loop it should be header("Location: home.php"); instead of header("Location: index.php");
In home.php page you should put on top after opening php tag
ob_start();
session_start();
Hope it will work.
++++++++++++++++++++++++++++++++++++++++++
Use this code index.php
<?php
require_once('connect.php');
ob_start();
session_start();
//checked wether the user is loged in or not
$user = $_SESSION['username'];
if($_SESSION['username'])
{
$user = $_SESSION['username'];
header("Location: home.php");
exit();
}
// login script
if(isset($_POST['username'])&& isset($_POST['password']))
{
$user_login = preg_replace('#[^A-Za-z0-9]#i', '', $_POST['username']);
$user_password = preg_replace('#[^A-Za-z0-9]#i', '', $_POST['password']);
$md5password = md5($user_password);
$sql = mysql_query("SELECT id FROM members WHERE username = '".$user_login."' AND password = '".$user_password."'") or die ("could not select from database");
$userCount = mysql_num_rows($sql);
if($userCount ==1)
{
while($row = mysql_fetch_array($sql))
{
$id = $row['id'];
}
$_SESSION['id'] = $id;
$_SESSION['username'] = $user_login;
$_SESSION['password'] = $user_password;
header("Location: home.php");
exit();
}
else
{
echo "that info is incorrect";
exit();
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<form action="login.php" method="post">
<input name="username" type="text" value="username" size="32" />
<input name="pass" type="password" value="password" size="32" />
<input name="login" type="submit" value="login" />
</form>
</body>
</html>
<?php ob_end_flush(); ?>
home.php
<?php
ob_start();
session_start();
//home.php
$user = $_SESSION['username'];
if(!isset($_SESSION['username']))
{
header("Location: index.php");
exit();
}
else
{
echo "hi $user you are loged in //Welcome to our website <a href=\"logout.php\">Logout</a>";
}
?>
logout.php is correct
回答2:
First, in index.php you don't need to "//checked wether the user is loged in or not", we should check that in home.php. This code is causing your error : "The page isn't redirecting properly Firefox has detected that the server is redirecting the request for this address in a way that will never complete". You made a repetition (The session is not created but it is checked ...).
Second, in home.php, You have to write session_start() method, this is the code require when using session.
Refer my code:
index.php
<?php
ob_start();
session_start();
//check session is existed
if (isset($_SESSION['username'])) {
header("Location: home.php");
}
if (isset($_POST['username']) && isset($_POST['password'])) {
$user_login = $_POST['username'];
$user_password = $_POST['password'];
if ($user_login == 'namluu' && $user_password =='123456') {
$_SESSION['username'] = $user_login;
$_SESSION['password'] = $user_password;
header("Location: home.php");
exit();
} else {
echo 'Infor not correct';
exit();
}
}
?>
<html>
<head></head>
<body>
<form action="index.php" method="post">
<input type="text" name="username" />
<input type="text" name="password" />
<input type="submit" name="login" value="login" />
</form>
</body>
</html>
<?php
ob_end_flush();
?>
home.php
<?php
session_start();
//home.php
$user = $_SESSION['username'];
if(!isset($_SESSION['username']))
{
header("Location: index.php");
exit();
}
else
{
echo "hi $user you are loged in //Welcome to our website <a href=\"logout.php\">Logout</a>";
}
?>
回答3:
You haven't got session_start() at the top of home.php, which means you will have created an infinite loop between home.php and index.php.
Currently what is happening is when you access index.php, it recognises the session and redirects the user to home.php. As there is no session_start() in home.php, it doesn't recognise the session and redirects the user back to index.php. Thus you have an infinite loop.
来源：https://stackoverflow.com/questions/15274352/php-mysql-session-problems