Sessions in PHP 4.3.2

[Calahan]

I am studying a book which bases it's examples on setting register_globals to on as register_globals is a security risk (or so I'm told, I don't understand why, but don't really care at this stage of my learning).
So, I am trying to use a session to enable a personalised greeting when a user logs on based on examples from the book. This is what I have so far...

index.php containing a logon box and a password box. PHP code on this page is:

<?php
session_register('entered_username');
?>

Now the user enters his/her username and password and it is checked by login.php containing:

<?php
include("common.php");

if(!($link_id = mysql_connect($Host, $User, $Pass)))
{
die(mysql_error());
}
mysql_select_db($DB);

$sql = "SELECT ID FROM " . $Table . " WHERE username='" . $_POST['username'] . "' AND password='" . md5($_POST['password']) . "' LIMIT 1";
if(!($result = mysql_query($sql))) 
{
	die(mysql_error());
}
if(mysql_num_rows($result) == 1)
{  

   $entered_username="" . $_POST['username'];
   echo "You have been validated " . $entered_username . ". <br><a href='member.php'>Click here</a> to return to the login page.";
}
else 
{
    echo "Login failure";
}
?> 

Although the login.php page shows up, I get this message:

Warning: Unknown(): Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively. in Unknown on line 0

Now I know it's giving me the answer here but I would like to know why I'm following the instructions before I move on so could anyone either explain or point me to a link that will.

Cheers. 🙂

[stolzyboy]

change this

<?php
session_register('entered_username');
?>

to this

<?php
session_start();
$_SESSION['username'] = "";
?>

and this

$entered_username="" . $_POST['username'];

to this

$SESSION['username'] = $POST['username'];

[Calahan]

Thanks Stolzyboy. All now works as expected. My little website is coming together nicely now 🙂.
Is your solution the standard way of using sessions in the latest version of PHP or was that your personal way of doing it?
Also, if I disable cookies, the personal greeting fails showing enter_username as an undefined variable on the member.php page. I have read that sessions will pass the info to the URL if the cookies are disabled but clearly I'm missing something. I get a feeling that I should have changed a parameter in php.ini but am unsure of which one as there are a fair few for the session key.

Thanks for any pointers.

[stolzyboy]

i sure hope it's standard, i am writing a session chapter in an upcoming PHP book from wrox

[Calahan]

Whats the book called? When's it out? I was going to buy a wrox book a few days ago but all the ones I found were pretty old.

[stolzyboy]

Originally posted by Calahan
Whats the book called? When's it out? I was going to buy a wrox book a few days ago but all the ones I found were pretty old.

not sure when it will be out, not for months though