Session lost after page redirect in php - php

Question

When I use php header redirection all session variables are lost... Some people say that adding exit(); just after the header(""); will solve the problem but it doesn't seem to be the solution...
Can anyone please help?
Here is how I store variable into the session:
include 'dbc.php';
$err = array();
foreach($_GET as $key => $value) {
$get[$key] = filter($value); //get variables are filtered.
}
if ($_POST['doLogin']=='Login')
{
foreach($_POST as $key => $value) {
$data[$key] = filter($value); // post variables are filtered
}
$user_email = $data['usr_email'];
$pass = $data['pwd'];
if (strpos($user_email,'#') === false) {
$user_cond = "user_name='$user_email'";
} else {
$user_cond = "user_email='$user_email'";
}
$result = mysql_query("SELECT `id`,`pwd`,`full_name`,`approved`,`user_level` FROM users WHERE
$user_cond
AND `banned` = '0'
") or die (mysql_error());
$num = mysql_num_rows($result);
// Match row found with more than 1 results - the user is authenticated.
if ( $num > 0 ) {
list($id,$pwd,$full_name,$approved,$user_level) = mysql_fetch_row($result);
if(!$approved) {
//$msg = urlencode("Account not activated. Please check your email for activation code");
$err[] = "Account not activated. Please check your email for activation code";
//header("Location: login.php?msg=$msg");
//exit();
}
//check against salt
if ($pwd === PwdHash($pass,substr($pwd,0,9))) {
// this sets session and logs user in
session_start();
session_regenerate_id (true); //prevent against session fixation attacks.
// this sets variables in the session
$_SESSION['user_id']= $id;
$_SESSION['user_name'] = $full_name;
$_SESSION['user_level'] = $user_level;
$_SESSION['HTTP_USER_AGENT'] = md5($_SERVER['HTTP_USER_AGENT']);
//update the timestamp and key for cookie
$stamp = time();
$ckey = GenKey();
mysql_query("update users set `ctime`='$stamp', `ckey` = '$ckey' where id='$id'") or die(mysql_error());
//set a cookie
if(isset($_POST['remember'])){
setcookie("user_id", $_SESSION['user_id'], time()+60*60*24*COOKIE_TIME_OUT, "/");
setcookie("user_key", sha1($ckey), time()+60*60*24*COOKIE_TIME_OUT, "/");
setcookie("user_name",$_SESSION['user_name'], time()+60*60*24*COOKIE_TIME_OUT, "/");
}
if(empty($err)){
header("Location: myaccount.php");
}
}
else
{
//$msg = urlencode("Invalid Login. Please try again with correct user email and password. ");
$err[] = "Invalid Login. Please try again with correct user email and password.";
//header("Location: login.php?msg=$msg");
}
} else {
$err[] = "Error - Invalid login. No such user exists";
}
}
Redirection code:
//connect database
require_once 'dbc.php';
page_protect();
$authorID = $_SESSION['user_id'];
if ( !empty($_POST["answ_content"]) && $authorID != 0 ) {
//vaqciot html chveulebriv texad
$content = htmlentities($_POST["answ_content"],ENT_COMPAT,'UTF-8');
$dro = date('Y-m-d H:i:s');
$qID = $_POST["question_ID"];
$author = $_SESSION["user_name"];
$sql="INSERT INTO wp_comments (comment_ID, comment_post_ID, comment_author, comment_author_IP, comment_date, comment_content, user_id)
VALUES
(NULL, '$qID', '$author', '123.123.123.123', '$dro', '$content', '$authorID')";
$result = mysql_query($sql);
//pasuxebis raodenobis ertit gazrda
$increase = "UPDATE wp_posts SET comment_count = comment_count+1 WHERE ID = $qID";
mysql_query($increase);
//gadamisamarteba shekitxvis gverdze
$url = 'Location:http://example.com/site/answ/question.php?ID=' .$qID;
header($url);
} else {
echo 'error';
}

Answer 1

You need to put exit(); after your header redirection, otherwise you have just loaded two pages of content into 1 page.
Also make sure you have session_start(); at the top of all your scripts.

Answer 2

You aren't starting the session. In order to use session variables and have them carry across pages, you need to put
session_start();
at the top of each page before anything else.

Answer 3

I was trying to set the session id of my own using :
session_id('own_generated_session_id_string');
But as the documentation says, you have to use this before
session_start();
Using it after session_start(), clears the session parameters.

Answer 4

Simples! make sure the page you are coming from (e.g. www.example.com) redirects to a (eg.g www.example.com/redirect.php) notice www at the beginning. If you change that from page to page, then yes things get wonky.

Answer 5

These sessions does not always work as we expect sometimes. I had a similar problem with my website using sessions that get lost. I basically solved it by injecting the value I want to keep on the session into the hidden text field the first time the page loads. Then the second time I call the page(page submit) I simply read the value from the hidden text field and carry on with rest of my code.
That's more easier and cleaner than using sessions in this case!

Answer 6

exit; should be placed after header redirection or session_regenerate_id(true); can be used

Answer 7

You just need to check the file permission in /var/lib/php directory
give yje public permisssion to /var/lib/php/session directory.
and all done.

Answer 8

Include session_start(); in both the files before the session.
Note don't use session_destroy() in the redirected file.