问题
I have a PHP authentication system on my website using the $_SESSION variable.
A form submits a username and password to the file "login.php". It is handled like this:
<?php include '../includes/sessionstart.inc.php'; ?>
<?php ob_start(); ?>
if($_POST){
$q = mysql_query("SELECT id, company FROM users WHERE username = '".mysql_real_escape_string($_POST['username'])."' AND password = '".md5($_POST['password'])."'");
if(mysql_num_rows($q) >= 1){
$f = mysql_fetch_Array($q);
$_SESSION['company'] = $f['company'];
$_SESSION['id'] = $f['id'];
$_SESSION['logedin'] = true;
session_write_close();
ob_clean();
header("Location: index.php");
}
Afterwards, index.php is loaded and checks whether 'logedin' is true.
<?php include '../includes/sessionstart.inc.php'; ?>
<?php if(!isset($_SESSION['logedin'])) header('Location: login.php'); ?>
On my production server, it continues, but on my Wampserver, it reverts back to login.php. I notice that Wampserver is very slow in page loading, this might have to do something with it. That's why I included the session_write_close, to make sure session data is saved before the pages are switched, but it doesn't help.
The contents of session_start.inc.php are simply:
<?php
session_start();
?>
I used to have more code in there, but at the moment it's just this. The problem also existed before I started using an include file.
Does anybody have an idea what I'm doing wrong? Why doesn't Wampserver transmit my SESSION data to the next PHP file?
回答1:
WAMP server 2 - settings are not set by default for $_SESSION var.
PHP.ini requires the following settings
C:\wamp\bin\apache\apache2.4.2\bin\php.ini
session.cookie_domain =
session.use_cookies = 1
session.save_path = "c:\wamp\tmp" ;ensure the \ is used not /
Session testing -
load.php -- load $_SESSION var.
<?PHP
session_start();
$_SESSION['SESS_MEMBER_ID'] = 'stored variable';
session_write_close();
header("location:print.php");
?>
print.php -- print $_SESSION var.
<?PHP
session_start();
var_dump($_SESSION);
?>
run the script in your browser var_dump() should produce results
go to c:\wamp\tmp Files containing the session data will appear here.
回答2:
First of all: the index logedin seems strange for keeping track of a user being logged in. Is this just a typo on SO, or really a code-typo?
Second (depending on the desired behavior), try another approach for making pages login-protected. Your page should look something like
<?php
include 'login.inc.php';
if(authorized()) {
// put some more script here, if needed
?>
// put some plain HTML here
<?php
}
?>
Where login.inc.php handles the session, cookies. In particular, the authorized function should return TRUE if a client is already logged in. If a client is not logged in, it should display a form with action $_SERVER['PHP_SELF'] and return FALSE. If you name the submit-input something like login_submit, you can let login.inc.php handle the verification.
This way, you don't need to refer users to a dedicated login page, and after logging in, user are directly shown the requested page. You can tweak this a bit to make query-strings persistent through login as well.
回答3:
Try to replace
if($_POST){...}
with
if( isset($_POST['username']) && isset($_POST['password']) ){...}
... at least for debugging purposes. It's possible that some different settings are causing a non-empty $_POST array where it's not expected.
Also, your code seems to be missing exit() calls after header() redirections. Sending an HTTP Location header doesn't automatically stop your script.
回答4:
I had this problem using WAMPSERVER for development on /localhost. I needed to change session.use_only_cookies either in-line or in the php.ini setting from
session.use_only_cookies = 1
to
session.use_only_cookies = 0
Explanation
Using default cookie-based sessions was working as expected but I needed a cookie-less solution. A test starting page:
<?php
// page1.php
ini_set('session.use_cookies', '0');
session_start();
$_SESSION['time'] = time();
echo '<br /><a href="page2.php?' . SID . '">page 2</a>';
?>
The session data was created and stored successfully in the WAMPSERVER temp directory, e.g., C:\wamp\tmp\sess_0rkdlonl5uia717rf03d4svs16. The link generated by the above code looks similar to (note the UID matches the session data file name):
page2.php?PHPSESSID=0rkdlonl5uia717rf03d4svs16
But the destination page2.php was throwing undefined errors for the variable 'time' whilst attempting to retrieve the session data:
<?php
// page2.php
ini_set('session.use_cookies', '0');
session_start();
echo date('Y m d H:i:s', $_SESSION['time']);
echo '<br /><a href="page1.php?' . SID . '">page 1</a>';
?>
By setting session.use_only_cookies FALSE in either the script before session_start();:
ini_set('session.use_only_cookies', '0');
or changing it globally in php.ini:
; This option forces PHP to fetch and use a cookie for storing and maintaining
; the session id. We encourage this operation as it's very helpful in combatting
; session hijacking when not specifying and managing your own session id. It is
; not the end all be all of session hijacking defense, but it's a good start.
; http://php.net/session.use-only-cookies
session.use_only_cookies = 0
solved the problem.
回答5:
After a long time I have fixed this bug finally.
On my localhost WAMP, the session data is not saved between page loads, because the session data is stored in a cookie, and there is no cookie domain to be set for localhost.
The solution:
'session.cookie_domain' should be set to empty string for all local domain names, not only for 'localhost' (but should not be empty for local IP addresses):
<?php
ini_set('session.cookie_domain', (strpos($_SERVER['HTTP_HOST'],'.') !== false) ? $_SERVER['HTTP_HOST'] : '');
?>
Thanks to Marcin Wiazowski who posted it here.
回答6:
Faced the same problem but it was being caused by
session_regenerate_id(true);
So I just deleted it from my code.
回答7:
Update to WAMP 2.5 and now the problem is solved!
来源：https://stackoverflow.com/questions/2153465/php-session-data-lost-between-page-loads-with-wampserver-2-0-on-localhost