lib/setup.php

   1 <?php
   2 /**
   3  * setup.php - Sets up sessions, connects to databases and so on
   4  *
   5  * Normally this is only called by the main config.php file
   6  * Normally this file does not need to be edited.
   7  * @author Martin Dougiamas
   8  * @version $Id$
   9  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  10  * @package moodlecore
  11  */
  12
  13 ////// DOCUMENTATION IN PHPDOC FORMAT FOR MOODLE GLOBALS AND COMMON OBJECT TYPES /////////////
  14 /**
  15  * $USER is a global instance of a typical $user record.
  16  *
  17  * Items found in the user record:
  18  *  - $USER->emailstop - Does the user want email sent to them?
  19  *  - $USER->email - The user's email address.
  20  *  - $USER->id - The unique integer identified of this user in the 'user' table.
  21  *  - $USER->email - The user's email address.
  22  *  - $USER->firstname - The user's first name.
  23  *  - $USER->lastname - The user's last name.
  24  *  - $USER->username - The user's login username.
  25  *  - $USER->secret - The user's ?.
  26  *  - $USER->lang - The user's language choice.
  27  *
  28  * @global object(user) $USER
  29  */
  30 global $USER;
  31 /**
  32  * This global variable is read in from the 'config' table.
  33  *
  34  * Some typical settings in the $CFG global:
  35  *  - $CFG->wwwroot - Path to moodle index directory in url format.
  36  *  - $CFG->dataroot - Path to moodle index directory on server's filesystem.
  37  *  - $CFG->libdir  - Path to moodle's library folder on server's filesystem.
  38  *
  39  * @global object(cfg) $CFG
  40  */
  41 global $CFG;
  42 /**
  43  * Definition of session type
  44  * @global object(session) $SESSION
  45  */
  46 global $SESSION;
  47 /**
  48  * Definition of shared memory cache
  49  */
  50 global $MCACHE;
  51 /**
  52  * Definition of course type
  53  * @global object(course) $COURSE
  54  */
  55 global $COURSE;
  56 /**
  57  * Definition of db type
  58  * @global object(db) $db
  59  */
  60 global $db;
  61 /**
  62  * $THEME is a global that defines the site theme.
  63  *
  64  * Items found in the theme record:
  65  *  - $THEME->cellheading - Cell colors.
  66  *  - $THEME->cellheading2 - Alternate cell colors.
  67  *
  68  * @global object(theme) $THEME
  69  */
  70 global $THEME;
  71
  72 /**
  73  * HTTPSPAGEREQUIRED is a global to define if the page being displayed must run under HTTPS.
  74  *
  75  * It's primary goal is to allow 100% HTTPS pages when $CFG->loginhttps is enabled. Default to false.
  76  * It's enabled only by the httpsrequired() function and used in some pages to update some URLs
  77 */
  78 global $HTTPSPAGEREQUIRED;
  79
  80
  81 /// First try to detect some attacks on older buggy PHP versions
  82     if (isset($_REQUEST['GLOBALS']) || isset($_COOKIE['GLOBALS']) || isset($_FILES['GLOBALS'])) {
  83         die('Fatal: Illegal GLOBALS overwrite attempt detected!');
  84     }
  85
  86
  87     if (!isset($CFG->wwwroot)) {
  88         trigger_error('Fatal: $CFG->wwwroot is not configured! Exiting.');
  89         die;
  90     }
  91
  92 /// sometimes default PHP settings are borked on shared hosting servers, I wonder why they have to do that??
  93     @ini_set('precision', 14); // needed for upgrades and gradebook
  94
  95
  96 /// store settings from config.php in array in $CFG - we can use it later to detect problems and overrides
  97     $CFG->config_php_settings = (array)$CFG;
  98
  99 /// Set httpswwwroot default value (this variable will replace $CFG->wwwroot
 100 /// inside some URLs used in HTTPSPAGEREQUIRED pages.
 101     $CFG->httpswwwroot = $CFG->wwwroot;
 102
 103     $CFG->libdir   = $CFG->dirroot .'/lib';
 104
 105     require_once($CFG->libdir .'/setuplib.php');        // Functions that MUST be loaded first
 106
 107 /// Time to start counting
 108     init_performance_info();
 109
 110
 111 /// If there are any errors in the standard libraries we want to know!
 112     error_reporting(E_ALL);
 113
 114 /// Just say no to link prefetching (Moz prefetching, Google Web Accelerator, others)
 115 /// http://www.google.com/webmasters/faq.html#prefetchblock
 116     if (!empty($_SERVER['HTTP_X_moz']) && $_SERVER['HTTP_X_moz'] === 'prefetch'){
 117         header($_SERVER['SERVER_PROTOCOL'] . ' 404 Prefetch Forbidden');
 118         trigger_error('Prefetch request forbidden.');
 119         exit;
 120     }
 121
 122 /// Connect to the database using adodb
 123
 124 /// Set $CFG->dbfamily global
 125 /// and configure some other specific variables for each db BEFORE attempting the connection
 126     preconfigure_dbconnection();
 127
 128     require_once($CFG->libdir .'/adodb/adodb.inc.php'); // Database access functions
 129
 130     $db = &ADONewConnection($CFG->dbtype);
 131
 132     // See MDL-6760 for why this is necessary. In Moodle 1.8, once we start using NULLs properly,
 133     // we probably want to change this value to ''.
 134     $db->null2null = 'A long random string that will never, ever match something we want to insert into the database, I hope. \'';
 135
 136     error_reporting(0);  // Hide errors
 137
 138     if (!isset($CFG->dbpersist) or !empty($CFG->dbpersist)) {    // Use persistent connection (default)
 139         $dbconnected = $db->PConnect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 140     } else {                                                     // Use single connection
 141         $dbconnected = $db->Connect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 142     }
 143     if (! $dbconnected) {
 144         // In the name of protocol correctness, monitoring and performance
 145         // profiling, set the appropriate error headers for machine comsumption
 146         if (isset($_SERVER['SERVER_PROTOCOL'])) {
 147             // Avoid it with cron.php. Note that we assume it's HTTP/1.x
 148             header($_SERVER['SERVER_PROTOCOL'] . ' 503 Service Unavailable');
 149         }
 150         // and then for human consumption...
 151         echo '<html><body>';
 152         echo '<table align="center"><tr>';
 153         echo '<td style="color:#990000; text-align:center; font-size:large; border-width:1px; '.
 154              '    border-color:#000000; border-style:solid; border-radius: 20px; border-collapse: collapse; '.
 155              '    -moz-border-radius: 20px; padding: 15px">';
 156         echo '<p>Error: Database connection failed.</p>';
 157         echo '<p>It is possible that the database is overloaded or otherwise not running properly.</p>';
 158         echo '<p>The site administrator should also check that the database details have been correctly specified in config.php</p>';
 159         echo '</td></tr></table>';
 160         echo '</body></html>';
 161
 162         error_log('ADODB Error: '.$db->ErrorMsg()); // see MDL-14628
 163
 164         if (empty($CFG->noemailever) and !empty($CFG->emailconnectionerrorsto)) {
 165             if (file_exists($CFG->dataroot.'/emailcount')){
 166                 $fp = fopen($CFG->dataroot.'/emailcount', 'r');
 167                 $content = fread($fp, 24);
 168                 fclose($fp);
 169                 if((time() - (int)$content) > 600){
 170                     mail($CFG->emailconnectionerrorsto,
 171                         'WARNING: Database connection error: '.$CFG->wwwroot,
 172                         'Connection error: '.$CFG->wwwroot);
 173                     $fp = fopen($CFG->dataroot.'/emailcount', 'w');
 174                     fwrite($fp, time());
 175                 }
 176             } else {
 177                mail($CFG->emailconnectionerrorsto,
 178                     'WARNING: Database connection error: '.$CFG->wwwroot,
 179                     'Connection error: '.$CFG->wwwroot);
 180                $fp = fopen($CFG->dataroot.'/emailcount', 'w');
 181                fwrite($fp, time());
 182             }
 183         }
 184         die;
 185     }
 186
 187 /// Forcing ASSOC mode for ADOdb (some DBs default to FETCH_BOTH)
 188     $db->SetFetchMode(ADODB_FETCH_ASSOC);
 189
 190 /// Starting here we have a correct DB conection but me must avoid
 191 /// to execute any DB transaction until "set names" has been executed
 192 /// some lines below!
 193
 194     error_reporting(E_ALL);       // Show errors from now on.
 195
 196     if (!isset($CFG->prefix)) {   // Just in case it isn't defined in config.php
 197         $CFG->prefix = '';
 198     }
 199
 200
 201 /// Define admin directory
 202
 203     if (!isset($CFG->admin)) {   // Just in case it isn't defined in config.php
 204         $CFG->admin = 'admin';   // This is relative to the wwwroot and dirroot
 205     }
 206
 207 /// Increase memory limits if possible
 208     raise_memory_limit('96M');    // We should never NEED this much but just in case...
 209
 210 /// Load up standard libraries
 211
 212     require_once($CFG->libdir .'/textlib.class.php');   // Functions to handle multibyte strings
 213     require_once($CFG->libdir .'/weblib.php');          // Functions for producing HTML
 214     require_once($CFG->libdir .'/dmllib.php');          // Functions to handle DB data (DML)
 215     require_once($CFG->libdir .'/datalib.php');         // Legacy lib with a big-mix of functions.
 216     require_once($CFG->libdir .'/accesslib.php');       // Access control functions
 217     require_once($CFG->libdir .'/deprecatedlib.php');   // Deprecated functions included for backward compatibility
 218     require_once($CFG->libdir .'/moodlelib.php');       // Other general-purpose functions
 219     require_once($CFG->libdir .'/eventslib.php');       // Events functions
 220     require_once($CFG->libdir .'/grouplib.php');        // Groups functions
 221
 222     //point pear include path to moodles lib/pear so that includes and requires will search there for files before anywhere else
 223     //the problem is that we need specific version of quickforms and hacked excel files :-(
 224     ini_set('include_path', $CFG->libdir.'/pear' . PATH_SEPARATOR . ini_get('include_path'));
 225
 226 /// Disable errors for now - needed for installation when debug enabled in config.php
 227     if (isset($CFG->debug)) {
 228         $originalconfigdebug = $CFG->debug;
 229         unset($CFG->debug);
 230     } else {
 231         $originalconfigdebug = -1;
 232     }
 233
 234 /// Set the client/server and connection to utf8
 235 /// and configure some other specific variables for each db
 236     configure_dbconnection();
 237
 238 /// Load up any configuration from the config table
 239     $CFG = get_config();
 240
 241 /// Turn on SQL logging if required
 242     if (!empty($CFG->logsql)) {
 243         $db->LogSQL();
 244         // And override ADODB's default logging time
 245         if (isset($CFG->logsqlmintime)) {
 246             global $ADODB_PERF_MIN;
 247             $ADODB_PERF_MIN = $CFG->logsqlmintime;
 248         }
 249     }
 250
 251 /// Prevent warnings from roles when upgrading with debug on
 252     if (isset($CFG->debug)) {
 253         $originaldatabasedebug = $CFG->debug;
 254         unset($CFG->debug);
 255     } else {
 256         $originaldatabasedebug = -1;
 257     }
 258
 259
 260 /// For now, only needed under apache (and probably unstable in other contexts)
 261     if (function_exists('register_shutdown_function')) {
 262         register_shutdown_function('moodle_request_shutdown');
 263     }
 264
 265 /// Defining the site
 266     if ($SITE = get_site()) {
 267         /**
 268          * If $SITE global from {@link get_site()} is set then SITEID to $SITE->id, otherwise set to 1.
 269          */
 270         define('SITEID', $SITE->id);
 271         /// And the 'default' course
 272         $COURSE = clone($SITE);   // For now.  This will usually get reset later in require_login() etc.
 273     } else {
 274         /**
 275          * @ignore
 276          */
 277         define('SITEID', 1);
 278         /// And the 'default' course
 279         $COURSE = new object;  // no site created yet
 280         $COURSE->id = 1;
 281     }
 282
 283     // define SYSCONTEXTID in config.php if you want to save some queries (after install or upgrade!)
 284     if (!defined('SYSCONTEXTID')) {
 285         get_system_context();
 286     }
 287
 288 /// Set error reporting back to normal
 289     if ($originaldatabasedebug == -1) {
 290         $CFG->debug = DEBUG_MINIMAL;
 291     } else {
 292         $CFG->debug = $originaldatabasedebug;
 293     }
 294     if ($originalconfigdebug !== -1) {
 295         $CFG->debug = $originalconfigdebug;
 296     }
 297     unset($originalconfigdebug);
 298     unset($originaldatabasedebug);
 299     error_reporting($CFG->debug);
 300
 301
 302 /// find out if PHP cofigured to display warnings
 303     if (ini_get_bool('display_errors')) {
 304         define('WARN_DISPLAY_ERRORS_ENABLED', true);
 305     }
 306 /// If we want to display Moodle errors, then try and set PHP errors to match
 307     if (!isset($CFG->debugdisplay)) {
 308         //keep it as is during installation
 309     } else if (empty($CFG->debugdisplay)) {
 310         @ini_set('display_errors', '0');
 311         @ini_set('log_errors', '1');
 312     } else {
 313         @ini_set('display_errors', '1');
 314     }
 315 // Even when users want to see errors in the output,
 316 // some parts of Moodle cannot display them at all.
 317 // (Once we are XHTML strict compliant, debugdisplay
 318 //  _must_ go away).
 319     if (defined('MOODLE_SANE_OUTPUT')) {
 320         @ini_set('display_errors', '0');
 321         @ini_set('log_errors', '1');
 322     }
 323
 324 /// Shared-Memory cache init -- will set $MCACHE
 325 /// $MCACHE is a global object that offers at least add(), set() and delete()
 326 /// with similar semantics to the memcached PHP API http://php.net/memcache
 327 /// Ensure we define rcache - so we can later check for it
 328 /// with a really fast and unambiguous $CFG->rcache === false
 329     if (!empty($CFG->cachetype)) {
 330         if (empty($CFG->rcache)) {
 331             $CFG->rcache = false;
 332         } else {
 333             $CFG->rcache = true;
 334         }
 335
 336         // do not try to initialize if cache disabled
 337         if (!$CFG->rcache) {
 338             $CFG->cachetype = '';
 339         }
 340
 341         if ($CFG->cachetype === 'memcached' && !empty($CFG->memcachedhosts)) {
 342             if (!init_memcached()) {
 343                 debugging("Error initialising memcached");
 344                 $CFG->cachetype = '';
 345                 $CFG->rcache = false;
 346             }
 347         } else if ($CFG->cachetype === 'eaccelerator') {
 348             if (!init_eaccelerator()) {
 349                 debugging("Error initialising eaccelerator cache");
 350                 $CFG->cachetype = '';
 351                 $CFG->rcache = false;
 352             }
 353         }
 354
 355     } else { // just make sure it is defined
 356         $CFG->cachetype = '';
 357         $CFG->rcache    = false;
 358     }
 359
 360 /// Set a default enrolment configuration (see bug 1598)
 361     if (!isset($CFG->enrol)) {
 362         $CFG->enrol = 'manual';
 363     }
 364
 365 /// Set default enabled enrolment plugins
 366     if (!isset($CFG->enrol_plugins_enabled)) {
 367         $CFG->enrol_plugins_enabled = 'manual';
 368     }
 369
 370 /// File permissions on created directories in the $CFG->dataroot
 371
 372     if (empty($CFG->directorypermissions)) {
 373         $CFG->directorypermissions = 0777;      // Must be octal (that's why it's here)
 374     }
 375
 376 /// Calculate and set $CFG->ostype to be used everywhere. Possible values are:
 377 /// - WINDOWS: for any Windows flavour.
 378 /// - UNIX: for the rest
 379 /// Also, $CFG->os can continue being used if more specialization is required
 380     if (stristr(PHP_OS, 'win') && !stristr(PHP_OS, 'darwin')) {
 381         $CFG->ostype = 'WINDOWS';
 382     } else {
 383         $CFG->ostype = 'UNIX';
 384     }
 385     $CFG->os = PHP_OS;
 386
 387 /// Set up default frame target string, based on $CFG->framename
 388     $CFG->frametarget = frametarget();
 389
 390 /// Setup cache dir for Smarty and others
 391     if (!file_exists($CFG->dataroot .'/cache')) {
 392         make_upload_directory('cache');
 393     }
 394
 395 /// Set up smarty template system
 396     //require_once($CFG->libdir .'/smarty/Smarty.class.php');
 397     //$smarty = new Smarty;
 398     //$smarty->template_dir = $CFG->dirroot .'/templates/'. $CFG->template;
 399     //if (!file_exists($CFG->dataroot .'/cache/smarty')) {
 400     //    make_upload_directory('cache/smarty');
 401     //}
 402     //$smarty->compile_dir = $CFG->dataroot .'/cache/smarty';
 403
 404 /// Set up session handling
 405     if(empty($CFG->respectsessionsettings)) {
 406         if (empty($CFG->dbsessions)) {   /// File-based sessions
 407
 408             // Some distros disable GC by setting probability to 0
 409             // overriding the PHP default of 1
 410             // (gc_probability is divided by gc_divisor, which defaults to 1000)
 411             if (ini_get('session.gc_probability') == 0) {
 412                 ini_set('session.gc_probability', 1);
 413             }
 414
 415             if (!empty($CFG->sessiontimeout)) {
 416                 ini_set('session.gc_maxlifetime', $CFG->sessiontimeout);
 417             }
 418
 419             if (!file_exists($CFG->dataroot .'/sessions')) {
 420                 make_upload_directory('sessions');
 421             }
 422             ini_set('session.save_path', $CFG->dataroot .'/sessions');
 423
 424         } else {                         /// Database sessions
 425             ini_set('session.save_handler', 'user');
 426
 427             $ADODB_SESSION_DRIVER  = $CFG->dbtype;
 428             $ADODB_SESSION_CONNECT = $CFG->dbhost;
 429             $ADODB_SESSION_USER    = $CFG->dbuser;
 430             $ADODB_SESSION_PWD     = $CFG->dbpass;
 431             $ADODB_SESSION_DB      = $CFG->dbname;
 432             $ADODB_SESSION_TBL     = $CFG->prefix.'sessions2';
 433             if (!empty($CFG->sessiontimeout)) {
 434                 $ADODB_SESS_LIFE   = $CFG->sessiontimeout;
 435             }
 436
 437             require_once($CFG->libdir. '/adodb/session/adodb-session2.php');
 438         }
 439     }
 440 /// Set sessioncookie and sessioncookiepath variable if it isn't already
 441     if (!isset($CFG->sessioncookie)) {
 442         $CFG->sessioncookie = '';
 443     }
 444     if (!isset($CFG->sessioncookiedomain)) {
 445         $CFG->sessioncookiedomain = '';
 446     }
 447     if (!isset($CFG->sessioncookiepath)) {
 448         $CFG->sessioncookiepath = '/';
 449     }
 450
 451 /// Configure ampersands in URLs
 452
 453     @ini_set('arg_separator.output', '&amp;');
 454
 455 /// Work around for a PHP bug   see MDL-11237
 456
 457     @ini_set('pcre.backtrack_limit', 20971520);  // 20 MB
 458
 459 /// Location of standard files
 460
 461     $CFG->wordlist    = $CFG->libdir .'/wordlist.txt';
 462     $CFG->javascript  = $CFG->libdir .'/javascript.php';
 463     $CFG->moddata     = 'moddata';
 464
 465 // Alas, in some cases we cannot deal with magic_quotes.
 466     if (defined('MOODLE_SANE_INPUT') && ini_get_bool('magic_quotes_gpc')) {
 467         mdie("Facilities that require MOODLE_SANE_INPUT "
 468              . "cannot work with magic_quotes_gpc. Please disable "
 469              . "magic_quotes_gpc.");
 470     }
 471 /// A hack to get around magic_quotes_gpc being turned off
 472 /// It is strongly recommended to enable "magic_quotes_gpc"!
 473     if (!ini_get_bool('magic_quotes_gpc') && !defined('MOODLE_SANE_INPUT') ) {
 474         function addslashes_deep($value) {
 475             $value = is_array($value) ?
 476                     array_map('addslashes_deep', $value) :
 477                     addslashes($value);
 478             return $value;
 479         }
 480         $_POST = array_map('addslashes_deep', $_POST);
 481         $_GET = array_map('addslashes_deep', $_GET);
 482         $_COOKIE = array_map('addslashes_deep', $_COOKIE);
 483         $_REQUEST = array_map('addslashes_deep', $_REQUEST);
 484         if (!empty($_SERVER['REQUEST_URI'])) {
 485             $_SERVER['REQUEST_URI'] = addslashes($_SERVER['REQUEST_URI']);
 486         }
 487         if (!empty($_SERVER['QUERY_STRING'])) {
 488             $_SERVER['QUERY_STRING'] = addslashes($_SERVER['QUERY_STRING']);
 489         }
 490         if (!empty($_SERVER['HTTP_REFERER'])) {
 491             $_SERVER['HTTP_REFERER'] = addslashes($_SERVER['HTTP_REFERER']);
 492         }
 493        if (!empty($_SERVER['PATH_INFO'])) {
 494             $_SERVER['PATH_INFO'] = addslashes($_SERVER['PATH_INFO']);
 495         }
 496         if (!empty($_SERVER['PHP_SELF'])) {
 497             $_SERVER['PHP_SELF'] = addslashes($_SERVER['PHP_SELF']);
 498         }
 499         if (!empty($_SERVER['PATH_TRANSLATED'])) {
 500             $_SERVER['PATH_TRANSLATED'] = addslashes($_SERVER['PATH_TRANSLATED']);
 501         }
 502     }
 503
 504 /// neutralise nasty chars in PHP_SELF
 505     if (isset($_SERVER['PHP_SELF'])) {
 506         $phppos = strpos($_SERVER['PHP_SELF'], '.php');
 507         if ($phppos !== false) {
 508             $_SERVER['PHP_SELF'] = substr($_SERVER['PHP_SELF'], 0, $phppos+4);
 509         }
 510         unset($phppos);
 511     }
 512
 513 /// The following code can emulate "register globals" if required.
 514 /// This hack is no longer being applied as of Moodle 1.6 unless you really
 515 /// really want to use it (by defining  $CFG->enableglobalshack = true)
 516
 517     if (!empty($CFG->enableglobalshack) && !defined('MOODLE_SANE_INPUT')) {
 518         if (!empty($CFG->detect_unchecked_vars)) {
 519             global $UNCHECKED_VARS;
 520             $UNCHECKED_VARS->url = $_SERVER['PHP_SELF'];
 521             $UNCHECKED_VARS->vars = array();
 522         }
 523         if (isset($_GET)) {
 524             extract($_GET, EXTR_SKIP);    // Skip existing variables, ie CFG
 525             if (!empty($CFG->detect_unchecked_vars)) {
 526                 foreach ($_GET as $key => $val) {
 527                     $UNCHECKED_VARS->vars[$key]=$val;
 528                 }
 529             }
 530         }
 531         if (isset($_POST)) {
 532             extract($_POST, EXTR_SKIP);   // Skip existing variables, ie CFG
 533             if (!empty($CFG->detect_unchecked_vars)) {
 534                 foreach ($_POST as $key => $val) {
 535                     $UNCHECKED_VARS->vars[$key]=$val;
 536                 }
 537             }
 538         }
 539         if (isset($_SERVER)) {
 540             extract($_SERVER);
 541         }
 542     }
 543
 544
 545 /// Load up global environment variables
 546
 547     if (!isset($CFG->cookiesecure) or strpos($CFG->wwwroot, 'https://') !== 0) {
 548         $CFG->cookiesecure = false;
 549     }
 550
 551     if (!isset($CFG->cookiehttponly)) {
 552         $CFG->cookiehttponly = false;
 553     }
 554
 555     //discard session ID from POST, GET and globals to tighten security,
 556     //this session fixation prevention can not be used in cookieless mode
 557     if (empty($CFG->usesid) && !defined('MOODLE_SANE_INPUT')) {
 558         unset(${'MoodleSession'.$CFG->sessioncookie});
 559         unset($_GET['MoodleSession'.$CFG->sessioncookie]);
 560         unset($_POST['MoodleSession'.$CFG->sessioncookie]);
 561     }
 562     //compatibility hack for Moodle Cron, cookies not deleted, but set to "deleted" - should not be needed with $nomoodlecookie in cron.php now
 563     if (!empty($_COOKIE['MoodleSession'.$CFG->sessioncookie]) && $_COOKIE['MoodleSession'.$CFG->sessioncookie] == "deleted") {
 564         unset($_COOKIE['MoodleSession'.$CFG->sessioncookie]);
 565     }
 566     if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] == "deleted") {
 567         unset($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]);
 568     }
 569     if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 570         require_once("$CFG->dirroot/lib/cookieless.php");
 571         sid_start_ob();
 572     }
 573
 574     if (empty($nomoodlecookie)) {
 575         session_name('MoodleSession'.$CFG->sessioncookie);
 576         if (check_php_version('5.2.0')) {
 577             session_set_cookie_params(0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure, $CFG->cookiehttponly);
 578         } else {
 579             session_set_cookie_params(0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure);
 580         }
 581         @session_start();
 582         if (! isset($_SESSION['SESSION'])) {
 583             $_SESSION['SESSION'] = new object;
 584             $_SESSION['SESSION']->session_test = random_string(10);
 585             if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 586                 $_SESSION['SESSION']->has_timed_out = true;
 587             }
 588             if (check_php_version('5.2.0')) {
 589                 setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure, $CFG->cookiehttponly);
 590             } else {
 591                 setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure);
 592             }
 593             $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
 594         }
 595         if (! isset($_SESSION['USER']))    {
 596             $_SESSION['USER']    = new object;
 597         }
 598
 599         $SESSION = &$_SESSION['SESSION'];   // Makes them easier to reference
 600         $USER    = &$_SESSION['USER'];
 601         if (!isset($USER->id)) {
 602             $USER->id = 0; // to enable proper function of $CFG->notloggedinroleid hack
 603         }
 604     }
 605     else {
 606         $SESSION  = NULL;
 607         $USER     = new object();
 608         $USER->id = 0; // user not logged in when session disabled
 609         if (isset($CFG->mnet_localhost_id)) {
 610             $USER->mnethostid = $CFG->mnet_localhost_id;
 611         }
 612     }
 613
 614     if (defined('FULLME')) {     // Usually in command-line scripts like admin/cron.php
 615         $FULLME = FULLME;
 616         $ME = FULLME;
 617     } else {
 618         $FULLME = qualified_me();
 619         $ME = strip_querystring($FULLME);
 620     }
 621
 622 /// In VERY rare cases old PHP server bugs (it has been found on PHP 4.1.2 running
 623 /// as a CGI under IIS on Windows) may require that you uncomment the following:
 624 //  session_register("USER");
 625 //  session_register("SESSION");
 626
 627
 628
 629 /// Load up theme variables (colours etc)
 630
 631     if (!isset($CFG->themedir)) {
 632         $CFG->themedir = $CFG->dirroot.'/theme';
 633         $CFG->themewww = $CFG->wwwroot.'/theme';
 634     }
 635     $CFG->httpsthemewww = $CFG->themewww;
 636
 637     if (isset($_GET['theme'])) {
 638         if ($CFG->allowthemechangeonurl || confirm_sesskey()) {
 639             $themename = clean_param($_GET['theme'], PARAM_SAFEDIR);
 640             if (($themename != '') and file_exists($CFG->themedir.'/'.$themename)) {
 641                 $SESSION->theme = $themename;
 642             }
 643             unset($themename);
 644         }
 645     }
 646
 647     if (!isset($CFG->theme)) {
 648         $CFG->theme = 'standardwhite';
 649     }
 650
 651 /// now do a session test to prevent random user switching - observed on some PHP/Apache combinations,
 652 /// disable checks when working in cookieless mode
 653     if (empty($CFG->usesid) || !empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 654         if ($SESSION != NULL) {
 655             if (empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 656                 report_session_error();
 657             } else if (isset($SESSION->session_test) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] != $SESSION->session_test) {
 658                 report_session_error();
 659             }
 660         }
 661     }
 662
 663
 664 /// Set language/locale of printed times.  If user has chosen a language that
 665 /// that is different from the site language, then use the locale specified
 666 /// in the language file.  Otherwise, if the admin hasn't specified a locale
 667 /// then use the one from the default language.  Otherwise (and this is the
 668 /// majority of cases), use the stored locale specified by admin.
 669     if ($SESSION !== NULL && isset($_GET['lang']) && ($lang = clean_param($_GET['lang'], PARAM_SAFEDIR))) {
 670         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
 671             $SESSION->lang = $lang;
 672         } else if (file_exists($CFG->dataroot.'/lang/'.$lang.'_utf8') or
 673                    file_exists($CFG->dirroot .'/lang/'.$lang.'_utf8')) {
 674             $SESSION->lang = $lang.'_utf8';
 675         }
 676     }
 677
 678     setup_lang_from_browser();
 679
 680     unset($lang);
 681
 682     if (empty($CFG->lang)) {
 683         if (empty($SESSION->lang)) {
 684             $CFG->lang = 'en_utf8';
 685         } else {
 686             $CFG->lang = $SESSION->lang;
 687         }
 688     }
 689
 690     // set default locale and themes - might be changed again later from require_login()
 691     course_setup();
 692
 693     if (!empty($CFG->opentogoogle)) {
 694         if (empty($USER->id)) {  // Ignore anyone logged in
 695             if (!empty($_SERVER['HTTP_USER_AGENT'])) {
 696                 if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false ) {
 697                     $USER = guest_user();
 698                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'google.com') !== false ) { // Google
 699                     $USER = guest_user();
 700                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'Yahoo! Slurp') !== false ) {  // Yahoo
 701                     $USER = guest_user();
 702                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], '[ZSEBOT]') !== false ) {  // Zoomspider
 703                     $USER = guest_user();
 704                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSNBOT') !== false ) {  // MSN Search
 705                     $USER = guest_user();
 706                 }
 707             }
 708             if (!empty($CFG->guestloginbutton) && empty($USER) && !empty($_SERVER['HTTP_REFERER'])) {
 709                 if (strpos($_SERVER['HTTP_REFERER'], 'google') !== false ) {
 710                     $USER = guest_user();
 711                 } else if (strpos($_SERVER['HTTP_REFERER'], 'altavista') !== false ) {
 712                     $USER = guest_user();
 713                 }
 714             }
 715             if (!empty($USER)) {
 716                 load_all_capabilities();
 717             }
 718         }
 719     }
 720
 721     if (!empty($CFG->guestloginbutton)) {
 722         if ($CFG->theme == 'standard' or $CFG->theme == 'standardwhite') {    // Temporary measure to help with XHTML validation
 723             if (isset($_SERVER['HTTP_USER_AGENT']) and empty($_SESSION['USER']->id)) {      // Allow W3CValidator in as user called w3cvalidator (or guest)
 724                 if ((strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) or
 725                     (strpos($_SERVER['HTTP_USER_AGENT'], 'Cynthia') !== false )) {
 726                     if ($USER = get_complete_user_data("username", "w3cvalidator")) {
 727                         $USER->ignoresesskey = true;
 728                     } else {
 729                         $USER = guest_user();
 730                     }
 731                 }
 732             }
 733         }
 734     }
 735
 736 /// Apache log intergration. In apache conf file one can use ${MOODULEUSER}n in
 737 /// LogFormat to get the current logged in username in moodle.
 738     if ($USER && function_exists('apache_note')
 739         && !empty($CFG->apacheloguser) && isset($USER->username)) {
 740         $apachelog_userid = $USER->id;
 741         $apachelog_username = clean_filename($USER->username);
 742         $apachelog_name = '';
 743         if (isset($USER->firstname)) {
 744             // We can assume both will be set
 745             // - even if to empty.
 746             $apachelog_name = clean_filename($USER->firstname . " " .
 747                                              $USER->lastname);
 748         }
 749         if (isset($USER->realuser)) {
 750             if ($realuser = get_record('user', 'id', $USER->realuser)) {
 751                 $apachelog_username = clean_filename($realuser->username." as ".$apachelog_username);
 752                 $apachelog_name = clean_filename($realuser->firstname." ".$realuser->lastname ." as ".$apachelog_name);
 753                 $apachelog_userid = clean_filename($realuser->id." as ".$apachelog_userid);
 754             }
 755         }
 756         switch ($CFG->apacheloguser) {
 757             case 3:
 758                 $logname = $apachelog_username;
 759                 break;
 760             case 2:
 761                 $logname = $apachelog_name;
 762                 break;
 763             case 1:
 764             default:
 765                 $logname = $apachelog_userid;
 766                 break;
 767         }
 768         apache_note('MOODLEUSER', $logname);
 769     }
 770
 771 /// Adjust ALLOWED_TAGS
 772     adjust_allowed_tags();
 773
 774
 775 /// Use a custom script replacement if one exists
 776     if (!empty($CFG->customscripts)) {
 777         if (($customscript = custom_script_path()) !== false) {
 778             require ($customscript);
 779         }
 780     }
 781
 782 /// note: we can not block non utf-8 installatrions here, because empty mysql database
 783 /// might be converted to utf-8 in admin/index.php during installation
 784 ?>