API tools faq
paste
Advertisement
gitlez

YA: Check User Cookie For Login WC 20130620074829AAJvlEe

gitlez
Jun 20th, 2013
80
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
PHP 4.49 KB | None | 0 0
raw download clone embed print report
  1. <?php
  2. // Yahoo Ansers' Question: http://answers.yahoo.com/question/answer?qid=20130620074829AAJvlEe
  3.  
  4.  
  5. // Variable to hold the message we want displayed.
  6. $message = '';
  7.  
  8.  
  9. // Check and see if the $_COOKIE['username'] exists
  10. If(isset($_COOKIE['username'])) {
  11.    
  12.     // I'm assuming that the 'connect.php' file, automatically connects to your database.
  13.     // So you should NOT include it untill you need it. If the user doesn't poccess the
  14.     // the username cookie, then there is no need for the MySQL connection.
  15.     // Also, with include(), if php doesn't find the file to include, it simply shows
  16.     // an error message, but continues on anyways. In this case, it will cause some more
  17.     // errors and the process of the site will break. By using require_once(), it forces
  18.     // php to stop if it cannot locate the file. The '_once', part ensures that the file
  19.     // is only included one, so if the file is already loaded, it won't load it again.
  20.     // Not really needed here, but when you start nesting the includes, then it will be
  21.     // a good thing.
  22.     // Goto: http://www.php.net/manual/en/language.control-structures.php and look more
  23.     // at the include, include_once, require and require_once differences. There is
  24.     // definitely times to use each of them, knowing those differences is what will make
  25.     // you better.
  26.     require_once('connect.php');
  27.    
  28.    
  29.     // You must always assume that all user input is a possible security threat and
  30.     // you must treat it as so. The cookie is stored on the user's computer, where the
  31.     // user has access to it. This means that we must protect it from SQL Injection
  32.     // (Google it for more info).
  33.     $username = mysql_real_escape_string( $_COOKIE['username'] );
  34.    
  35.     // Statement to determine if username is legit.
  36.     // The { } are simply for readability and are optional. PHP Removes them when it
  37.     // replaces the variable value.
  38.     $sql = "SELECT user_id FROM users WHERE username='{$username}' LIMIT 1";
  39.    
  40.     $result = mysql_query($sql);
  41.    
  42.     // Check to make sure statement and query are good.
  43.     if( !$result ){
  44.         // Query mis-formed, Connection failed or an internal error with MySQL.
  45.         // Display error, but you could easily change it to log the error and tell
  46.         // the user a default error message.
  47.         $message .= 'Internal Error: ' . mysql_error();
  48.     }else if( mysql_num_rows($result) === 0){
  49.         // The query was successful, but did not match any rows in the database.
  50.         // In this case it means that the username is not in the database.
  51.         // I would suggest a message stating that they need to login again.
  52.         $message .= 'Welcome, Guest!<br />'; // As they do not have a valid username.
  53.     }else{
  54.         // Username Exists in database. Not sure if you want you want with the userid.
  55.         // If you need this information on other pages, I would strongly suggest not
  56.         // storing it in a COOKIE, but rather a SESSION ( http://php.net/manual/en/book.session.php
  57.         // && http://www.tizag.com/phpT/phpsessions.php );
  58.        
  59.         $row = mysql_fetch_assoc($result);
  60.         $user_id = $row['user_id'];
  61.         // Option 2: $user_id = mysql_fetch_object($result)->user_id;
  62.         // First one is probably more your style right now, just wanted to show you options.
  63.        
  64.         // Welcome Message.
  65.         $message .= 'Welcome . ' . $username . '!<br /><br />';
  66.         $message .= 'Your <a href="profile.php?id=' . $user_id . '">Profile Page</a> awaits.';
  67.     }
  68. } else {
  69.     // Default message, if $_COOKIE['username'] not set.
  70.     $message .= "Welcome, Guest! <br/>";
  71. }
  72.  
  73. ?>
  74. <html>
  75.     <head>
  76.         <title>Home</title>
  77.         <style type="text/css">
  78.             /***
  79.                 Although there is nothing wrong with putting it all on one line; It does make it easier to read this way.
  80.             ***/
  81.            
  82.             a:link {
  83.                 color: blue;
  84.                 text-decoration: none;
  85.             }
  86.             a:visited {
  87.                 color: purple;
  88.                 text-decoration: none;}
  89.             a:hover {
  90.                 color: black;
  91.                 text-decoration: none;
  92.             }
  93.             h3 {
  94.                 text-align: center;
  95.             }
  96.         </style>
  97.     </head>
  98.     <body>
  99.         <!-- Note: center elements are deprecated. -->
  100.         <h3>Home</h3>
  101.         <hr />
  102.         <br />
  103.         <br />
  104.         <?php echo $message; ?>
  105.     </body>
  106. </html>
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement
Public Pastes
Advertisement
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!