Reading/ Comparing usernames and Passwords from a text file

[vgf]

A really insecure and rather rudimentary way to go about a user system but i was just curious if anyone could take a look at what might be wrong with my code...

if (isset($_POST["user"]) && isset($_POST["pass"])){
	$userarray = file("users.txt");
	$count = count($userarray);	
	for($i=0; $i<$count; $i++){
		if ($user == $userarray[$i] && $password == $userarray[$i+1]){
			//(the password is one line beneath the username)
			$_SESSION['user']=$user;
			$_SESSION['pass']=$pass;
			$_SESSION['login'] = true;
			break;
		}
	}
}

Just sort of a crude thing I made in a rush but I can't seem to figure out what's wrong with it. I know that the original data is written to the file because I had the $userarray print at every interval to check. Any help and/or suggestions would be much appreciated.

[m_tt]

First things first... having the password on a seperate line makes things far more difficult. Why not seperate it with username : password?

Then you could just do something like this...

if (isset($_POST['user']) && isset($_POST['pass']))	{
	$userarray = file("users.txt");

foreach($userarray as $user)	{
	list($valid_username,$valid_password) = explode(":", $user);

	if ($_POST['user'] == $valid_username && $_POST['pass'] == $valid_password)	{
		// Register session
		break;
	}
}
}

I'm also always paranoid with using basic for loops and avoid them at all costs.

As for problems with your original code, I would guess its the undefined $user and $password variables. If register globals is on, it should be $pass not $password

[vgf]

Thanks a lot--your way does make more sense and it's working (to my knowledge) now.