View file session.php

<?php

session_start();

function registerUser($user,$pass1,$pass2,$email){
$errorText = '';
// Check passwords
if ($pass1 != $pass2) $errorText = "<img src=\"img/7_5.gif\"/><br/>Passwords are not identical!";
elseif (strlen($pass1) < 4) $errorText = "Password is to short!";

// Check user existance
$pfile = fopen("user_data.php","a+");
rewind($pfile);

while (!feof($pfile)) {
$line = fgets($pfile);
$tmp = explode(':', $line);
if ($tmp[0] == $user) {
$errorText = "<img src=\"img/7_5.gif\"/><br/>The selected user name is taken!";
break;
}
}

// If everything is OK -> store user data
if ($errorText == ''){
// Secure password string
$userpass = md5($pass1);

fwrite($pfile, "\r\n$user:$userpass:$email");
}

fclose($pfile);


return $errorText;
}

function loginUser($user,$pass){
$errorText = '';
$validUser = false;

// Check user existance
$pfile = fopen("user_data.php","r");
rewind($pfile);

while (!feof($pfile)) {
$line = fgets($pfile);
$tmp = explode(':', $line);
if ($tmp[0] == $user) {
// User exists, check password
if (trim($tmp[1]) == trim(md5($pass))){
$validUser= true;
$_SESSION['userName'] = $user;
}
break;
}
}
fclose($pfile);

if ($validUser != true) $errorText = "<img src=\"img/7_5.gif\"/><br/>Invalid username or password!";

if ($validUser == true) $_SESSION['validUser'] = true;
else $_SESSION['validUser'] = false;

return $errorText;
}

function logoutUser(){
unset($_SESSION['validUser']);
unset($_SESSION['userName']);
}

function checkUser(){
if ((!isset($_SESSION['validUser'])) || ($_SESSION['validUser'] != true)){
header('Location: login.php');
}
}
?>