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 /// Set httpswwwroot default value (this variable will replace $CFG->wwwroot
  93 /// inside some URLs used in HTTPSPAGEREQUIRED pages.
  94     $CFG->httpswwwroot = $CFG->wwwroot;
  95
  96     $CFG->libdir   = $CFG->dirroot .'/lib';
  97
  98     require_once($CFG->libdir .'/setuplib.php');        // Functions that MUST be loaded first
  99
 100 /// Time to start counting
 101     init_performance_info();
 102
 103
 104 /// If there are any errors in the standard libraries we want to know!
 105     error_reporting(E_ALL);
 106
 107 /// Just say no to link prefetching (Moz prefetching, Google Web Accelerator, others)
 108 /// http://www.google.com/webmasters/faq.html#prefetchblock
 109     if (!empty($_SERVER['HTTP_X_moz']) && $_SERVER['HTTP_X_moz'] === 'prefetch'){
 110         header($_SERVER['SERVER_PROTOCOL'] . ' 404 Prefetch Forbidden');
 111         trigger_error('Prefetch request forbidden.');
 112         exit;
 113     }
 114
 115 /// Connect to the database using adodb
 116
 117 /// Some defines required BEFORE including AdoDB library
 118     define ('ADODB_ASSOC_CASE', 0); //Use lowercase fieldnames for ADODB_FETCH_ASSOC
 119                                     //(only meaningful for oci8po, it's the default
 120                                     //for other DB drivers so this won't affect them)
 121
 122     require_once($CFG->libdir .'/adodb/adodb.inc.php'); // Database access functions
 123
 124     $db = &ADONewConnection($CFG->dbtype);
 125
 126     // See MDL-6760 for why this is necessary. In Moodle 1.8, once we start using NULLs properly,
 127     // we probably want to change this value to ''.
 128     $db->null2null = 'A long random string that will never, ever match something we want to insert into the database, I hope. \'';
 129
 130     error_reporting(0);  // Hide errors
 131
 132     if (!isset($CFG->dbpersist) or !empty($CFG->dbpersist)) {    // Use persistent connection (default)
 133         $dbconnected = $db->PConnect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 134     } else {                                                     // Use single connection
 135         $dbconnected = $db->Connect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 136     }
 137     if (! $dbconnected) {
 138         // In the name of protocol correctness, monitoring and performance
 139         // profiling, set the appropriate error headers for machine comsumption
 140         if (isset($_SERVER['SERVER_PROTOCOL'])) {
 141             // Avoid it with cron.php. Note that we assume it's HTTP/1.x
 142             header($_SERVER['SERVER_PROTOCOL'] . ' 503 Service Unavailable');
 143         }
 144         // and then for human consumption...
 145         echo '<html><body>';
 146         echo '<table align="center"><tr>';
 147         echo '<td style="color:#990000; text-align:center; font-size:large; border-width:1px; '.
 148              '    border-color:#000000; border-style:solid; border-radius: 20px; border-collapse: collapse; '.
 149              '    -moz-border-radius: 20px; padding: 15px">';
 150         echo '<p>Error: Database connection failed.</p>';
 151         echo '<p>It is possible that the database is overloaded or otherwise not running properly.</p>';
 152         echo '<p>The site administrator should also check that the database details have been correctly specified in config.php</p>';
 153         echo '</td></tr></table>';
 154         echo '</body></html>';
 155
 156         if (!empty($CFG->emailconnectionerrorsto)) {
 157             mail($CFG->emailconnectionerrorsto,
 158                  'WARNING: Database connection error: '.$CFG->wwwroot,
 159                  'Connection error: '.$CFG->wwwroot);
 160         }
 161         die;
 162     }
 163
 164 /// Forcing ASSOC mode for ADOdb (some DBs default to FETCH_BOTH)
 165     $db->SetFetchMode(ADODB_FETCH_ASSOC);
 166
 167 /// Starting here we have a correct DB conection but me must avoid
 168 /// to execute any DB transaction until "set names" has been executed
 169 /// some lines below!
 170
 171     error_reporting(E_ALL);       // Show errors from now on.
 172
 173     if (!isset($CFG->prefix)) {   // Just in case it isn't defined in config.php
 174         $CFG->prefix = '';
 175     }
 176
 177
 178 /// Define admin directory
 179
 180     if (!isset($CFG->admin)) {   // Just in case it isn't defined in config.php
 181         $CFG->admin = 'admin';   // This is relative to the wwwroot and dirroot
 182     }
 183
 184 /// Increase memory limits if possible
 185     raise_memory_limit('96M');    // We should never NEED this much but just in case...
 186
 187 /// Load up standard libraries
 188
 189     require_once($CFG->libdir .'/textlib.class.php');   // Functions to handle multibyte strings
 190     require_once($CFG->libdir .'/weblib.php');          // Functions for producing HTML
 191     require_once($CFG->libdir .'/dmllib.php');          // Functions to handle DB data (DML)
 192     require_once($CFG->libdir .'/datalib.php');         // Legacy lib with a big-mix of functions.
 193     require_once($CFG->libdir .'/accesslib.php');       // Access control functions
 194     require_once($CFG->libdir .'/deprecatedlib.php');   // Deprecated functions included for backward compatibility
 195     require_once($CFG->libdir .'/moodlelib.php');       // Other general-purpose functions
 196     require_once($CFG->libdir .'/eventslib.php');       // Events functions
 197
 198 /// Disable errors for now - needed for installation when debug enabled in config.php
 199     if (isset($CFG->debug)) {
 200         $originalconfigdebug = $CFG->debug;
 201         unset($CFG->debug);
 202     } else {
 203         $originalconfigdebug = -1;
 204     }
 205
 206 /// Set the client/server and connection to utf8
 207 /// and configure some other specific variables for each db
 208     configure_dbconnection();
 209
 210 /// Load up any configuration from the config table
 211     unset($CFG->rcache);
 212     $CFG = get_config();
 213
 214 /// Turn on SQL logging if required
 215     if (!empty($CFG->logsql)) {
 216         $db->LogSQL();
 217     }
 218
 219 /// Prevent warnings from roles when upgrading with debug on
 220     if (isset($CFG->debug)) {
 221         $originaldatabasedebug = $CFG->debug;
 222         unset($CFG->debug);
 223     } else {
 224         $originaldatabasedebug = -1;
 225     }
 226
 227
 228 /// For now, only needed under apache (and probably unstable in other contexts)
 229     if (function_exists('apache_child_terminate')) {
 230         register_shutdown_function('moodle_request_shutdown');
 231     }
 232
 233 //// Defining the site
 234     if ($SITE = get_site()) {
 235         /**
 236          * If $SITE global from {@link get_site()} is set then SITEID to $SITE->id, otherwise set to 1.
 237          */
 238         define('SITEID', $SITE->id);
 239         /// And the 'default' course
 240         $COURSE = clone($SITE);   // For now.  This will usually get reset later in require_login() etc.
 241     } else {
 242         /**
 243          * @ignore
 244          */
 245         define('SITEID', 1);
 246         /// And the 'default' course
 247         $COURSE = new object;  // no site created yet
 248         $COURSE->id = 1;
 249     }
 250
 251
 252 /// Set error reporting back to normal
 253     if ($originaldatabasedebug == -1) {
 254         $CFG->debug = DEBUG_MINIMAL;
 255     } else {
 256         $CFG->debug = $originaldatabasedebug;
 257     }
 258     if ($originalconfigdebug !== -1) {
 259         $CFG->debug = $originalconfigdebug;
 260     }
 261     unset($originalconfigdebug);
 262     unset($originaldatabasedebug);
 263     error_reporting($CFG->debug);
 264
 265
 266 /// If we want to display Moodle errors, then try and set PHP errors to match
 267     if (!isset($CFG->debugdisplay)) {
 268         //keep it as is during installation
 269     } else if (empty($CFG->debugdisplay)) {
 270         @ini_set('display_errors', '0');
 271         @ini_set('log_errors', '1');
 272     } else {
 273         @ini_set('display_errors', '1');
 274     }
 275
 276 /// Shared-Memory cache init -- will set $MCACHE
 277 /// $MCACHE is a global object that offers at least add(), set() and delete()
 278 /// with similar semantics to the memcached PHP API http://php.net/memcache
 279     if (!empty($CFG->cachetype)) {
 280         if ($CFG->cachetype === 'memcached' && !empty($CFG->memcachedhosts)) {
 281             if (!init_memcached()) {
 282                 debugging("Error initialising memcached");
 283             }
 284         } elseif ($CFG->cachetype === 'eaccelerator') {
 285             if (!init_eaccelerator()) {
 286                 debugging("Error initialising eaccelerator cache");
 287             }
 288         }
 289     } else { // just make sure it is defined
 290         $CFG->cachetype = '';
 291     }
 292 /// Ensure we define rcache - so we can later check for it
 293 /// with a really fast and unambiguous $CFG->rcache === false
 294     if (empty($CFG->rcache)) {
 295         $CFG->rcache = false;
 296     } else {
 297         $CFG->rcache = true;
 298     }
 299
 300 /// Set a default enrolment configuration (see bug 1598)
 301     if (!isset($CFG->enrol)) {
 302         $CFG->enrol = 'manual';
 303     }
 304
 305 /// Set default enabled enrolment plugins
 306     if (!isset($CFG->enrol_plugins_enabled)) {
 307         $CFG->enrol_plugins_enabled = 'manual';
 308     }
 309
 310 /// File permissions on created directories in the $CFG->dataroot
 311
 312     if (empty($CFG->directorypermissions)) {
 313         $CFG->directorypermissions = 0777;      // Must be octal (that's why it's here)
 314     }
 315
 316 /// Calculate and set $CFG->ostype to be used everywhere. Possible values are:
 317 /// - WINDOWS: for any Windows flavour.
 318 /// - UNIX: for the rest
 319 /// Also, $CFG->os can continue being used if more specialization is required
 320     if (stristr(PHP_OS, 'win') && !stristr(PHP_OS, 'darwin')) {
 321         $CFG->ostype = 'WINDOWS';
 322     } else {
 323         $CFG->ostype = 'UNIX';
 324     }
 325     $CFG->os = PHP_OS;
 326
 327 /// Set up default frame target string, based on $CFG->framename
 328     $CFG->frametarget = frametarget();
 329
 330 /// Setup cache dir for Smarty and others
 331     if (!file_exists($CFG->dataroot .'/cache')) {
 332         make_upload_directory('cache');
 333     }
 334
 335 /// Set up smarty template system
 336     //require_once($CFG->libdir .'/smarty/Smarty.class.php');
 337     //$smarty = new Smarty;
 338     //$smarty->template_dir = $CFG->dirroot .'/templates/'. $CFG->template;
 339     //if (!file_exists($CFG->dataroot .'/cache/smarty')) {
 340     //    make_upload_directory('cache/smarty');
 341     //}
 342     //$smarty->compile_dir = $CFG->dataroot .'/cache/smarty';
 343
 344 /// Set up session handling
 345     if(empty($CFG->respectsessionsettings)) {
 346         if (empty($CFG->dbsessions)) {   /// File-based sessions
 347
 348             // Some distros disable GC by setting probability to 0
 349             // overriding the PHP default of 1
 350             // (gc_probability is divided by gc_divisor, which defaults to 1000)
 351             if (ini_get('session.gc_probability') == 0) {
 352                 ini_set('session.gc_probability', 1);
 353             }
 354
 355             if (!empty($CFG->sessiontimeout)) {
 356                 ini_set('session.gc_maxlifetime', $CFG->sessiontimeout);
 357             }
 358
 359             if (!file_exists($CFG->dataroot .'/sessions')) {
 360                 make_upload_directory('sessions');
 361             }
 362             ini_set('session.save_path', $CFG->dataroot .'/sessions');
 363
 364         } else {                         /// Database sessions
 365             ini_set('session.save_handler', 'user');
 366
 367             $ADODB_SESSION_DRIVER  = $CFG->dbtype;
 368             $ADODB_SESSION_CONNECT = $CFG->dbhost;
 369             $ADODB_SESSION_USER    = $CFG->dbuser;
 370             $ADODB_SESSION_PWD     = $CFG->dbpass;
 371             $ADODB_SESSION_DB      = $CFG->dbname;
 372             $ADODB_SESSION_TBL     = $CFG->prefix.'sessions2';
 373             if (!empty($CFG->sessiontimeout)) {
 374                 $ADODB_SESS_LIFE   = $CFG->sessiontimeout;
 375             }
 376
 377             require_once($CFG->libdir. '/adodb/session/adodb-session2.php');
 378         }
 379     }
 380 /// Set sessioncookie variable if it isn't already
 381     if (!isset($CFG->sessioncookie)) {
 382         $CFG->sessioncookie = '';
 383     }
 384
 385 /// Configure ampersands in URLs
 386
 387     @ini_set('arg_separator.output', '&amp;');
 388
 389 /// Location of standard files
 390
 391     $CFG->wordlist    = $CFG->libdir .'/wordlist.txt';
 392     $CFG->javascript  = $CFG->libdir .'/javascript.php';
 393     $CFG->moddata     = 'moddata';
 394
 395
 396 /// A hack to get around magic_quotes_gpc being turned off
 397 /// It is strongly recommended to enable "magic_quotes_gpc"!
 398
 399     if (!ini_get_bool('magic_quotes_gpc') ) {
 400         function addslashes_deep($value) {
 401             $value = is_array($value) ?
 402                     array_map('addslashes_deep', $value) :
 403                     addslashes($value);
 404             return $value;
 405         }
 406         $_POST = array_map('addslashes_deep', $_POST);
 407         $_GET = array_map('addslashes_deep', $_GET);
 408         $_COOKIE = array_map('addslashes_deep', $_COOKIE);
 409         $_REQUEST = array_map('addslashes_deep', $_REQUEST);
 410         if (!empty($_SERVER['REQUEST_URI'])) {
 411             $_SERVER['REQUEST_URI'] = addslashes($_SERVER['REQUEST_URI']);
 412         }
 413         if (!empty($_SERVER['QUERY_STRING'])) {
 414             $_SERVER['QUERY_STRING'] = addslashes($_SERVER['QUERY_STRING']);
 415         }
 416         if (!empty($_SERVER['HTTP_REFERER'])) {
 417             $_SERVER['HTTP_REFERER'] = addslashes($_SERVER['HTTP_REFERER']);
 418         }
 419        if (!empty($_SERVER['PATH_INFO'])) {
 420             $_SERVER['PATH_INFO'] = addslashes($_SERVER['PATH_INFO']);
 421         }
 422         if (!empty($_SERVER['PHP_SELF'])) {
 423             $_SERVER['PHP_SELF'] = addslashes($_SERVER['PHP_SELF']);
 424         }
 425         if (!empty($_SERVER['PATH_TRANSLATED'])) {
 426             $_SERVER['PATH_TRANSLATED'] = addslashes($_SERVER['PATH_TRANSLATED']);
 427         }
 428     }
 429
 430
 431 /// The following code can emulate "register globals" if required.
 432 /// This hack is no longer being applied as of Moodle 1.6 unless you really
 433 /// really want to use it (by defining  $CFG->enableglobalshack = true)
 434
 435     if (!empty($CFG->enableglobalshack)) {
 436         if (!empty($CFG->detect_unchecked_vars)) {
 437             global $UNCHECKED_VARS;
 438             $UNCHECKED_VARS->url = $_SERVER['PHP_SELF'];
 439             $UNCHECKED_VARS->vars = array();
 440         }
 441
 442         if (isset($_GET)) {
 443             extract($_GET, EXTR_SKIP);    // Skip existing variables, ie CFG
 444             if (!empty($CFG->detect_unchecked_vars)) {
 445                 foreach ($_GET as $key => $val) {
 446                     $UNCHECKED_VARS->vars[$key]=$val;
 447                 }
 448             }
 449         }
 450         if (isset($_POST)) {
 451             extract($_POST, EXTR_SKIP);   // Skip existing variables, ie CFG
 452             if (!empty($CFG->detect_unchecked_vars)) {
 453                 foreach ($_POST as $key => $val) {
 454                     $UNCHECKED_VARS->vars[$key]=$val;
 455                 }
 456             }
 457         }
 458         if (isset($_SERVER)) {
 459             extract($_SERVER);
 460         }
 461     }
 462
 463
 464 /// Load up global environment variables
 465
 466     class object {};
 467
 468     //discard session ID from POST, GET and globals to tighten security,
 469     //this session fixation prevention can not be used in cookieless mode
 470     if (empty($CFG->usesid)) {
 471         unset(${'MoodleSession'.$CFG->sessioncookie});
 472         unset($_GET['MoodleSession'.$CFG->sessioncookie]);
 473         unset($_POST['MoodleSession'.$CFG->sessioncookie]);
 474     }
 475     //compatibility hack for Moodle Cron, cookies not deleted, but set to "deleted" - should not be needed with $nomoodlecookie in cron.php now
 476     if (!empty($_COOKIE['MoodleSession'.$CFG->sessioncookie]) && $_COOKIE['MoodleSession'.$CFG->sessioncookie] == "deleted") {
 477         unset($_COOKIE['MoodleSession'.$CFG->sessioncookie]);
 478     }
 479     if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] == "deleted") {
 480         unset($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]);
 481     }
 482     if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 483         require_once("$CFG->dirroot/lib/cookieless.php");
 484         sid_start_ob();
 485     }
 486
 487     if (empty($nomoodlecookie)) {
 488         session_name('MoodleSession'.$CFG->sessioncookie);
 489         @session_start();
 490         if (! isset($_SESSION['SESSION'])) {
 491             $_SESSION['SESSION'] = new object;
 492             $_SESSION['SESSION']->session_test = random_string(10);
 493             if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 494                 $_SESSION['SESSION']->has_timed_out = true;
 495             }
 496             setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, '/');
 497             $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
 498         }
 499         if (! isset($_SESSION['USER']))    {
 500             $_SESSION['USER']    = new object;
 501         }
 502
 503         $SESSION = &$_SESSION['SESSION'];   // Makes them easier to reference
 504         $USER    = &$_SESSION['USER'];
 505         if (!isset($USER->id)) {
 506             $USER->id = 0; // to enable proper function of $CFG->notloggedinroleid hack
 507         }
 508     }
 509     else {
 510         $SESSION  = NULL;
 511         $USER     = new object();
 512         $USER->id = 0; // user not logged in when session disabled
 513     }
 514
 515     if (defined('FULLME')) {     // Usually in command-line scripts like admin/cron.php
 516         $FULLME = FULLME;
 517         $ME = FULLME;
 518     } else {
 519         $FULLME = qualified_me();
 520         $ME = strip_querystring($FULLME);
 521     }
 522
 523 /// In VERY rare cases old PHP server bugs (it has been found on PHP 4.1.2 running
 524 /// as a CGI under IIS on Windows) may require that you uncomment the following:
 525 //  session_register("USER");
 526 //  session_register("SESSION");
 527
 528
 529
 530 /// Load up theme variables (colours etc)
 531
 532     if (!isset($CFG->themedir)) {
 533         $CFG->themedir = $CFG->dirroot.'/theme';
 534         $CFG->themewww = $CFG->wwwroot.'/theme';
 535     }
 536     $CFG->httpsthemewww = $CFG->themewww;
 537
 538     if (isset($_GET['theme'])) {
 539         if ($CFG->allowthemechangeonurl || confirm_sesskey()) {
 540             $themename = clean_param($_GET['theme'], PARAM_SAFEDIR);
 541             if (($themename != '') and file_exists($CFG->themedir.'/'.$themename)) {
 542                 $SESSION->theme = $themename;
 543             }
 544             unset($themename);
 545         }
 546     }
 547
 548     if (!isset($CFG->theme)) {
 549         $CFG->theme = 'standardwhite';
 550     }
 551
 552 /// now do a session test to prevent random user switching - observed on some PHP/Apache combinations,
 553 /// disable checks when working in cookieless mode
 554     if (empty($CFG->usesid) || !empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 555         if ($SESSION != NULL) {
 556             if (empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 557                 report_session_error();
 558             } else if (isset($SESSION->session_test) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] != $SESSION->session_test) {
 559                 report_session_error();
 560             }
 561         }
 562     }
 563
 564
 565 /// Set language/locale of printed times.  If user has chosen a language that
 566 /// that is different from the site language, then use the locale specified
 567 /// in the language file.  Otherwise, if the admin hasn't specified a locale
 568 /// then use the one from the default language.  Otherwise (and this is the
 569 /// majority of cases), use the stored locale specified by admin.
 570     if ($SESSION !== NULL && isset($_GET['lang']) && ($lang = clean_param($_GET['lang'], PARAM_SAFEDIR))) {
 571         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
 572             $SESSION->lang = $lang;
 573         } else if (file_exists($CFG->dataroot.'/lang/'.$lang.'_utf8') or
 574                    file_exists($CFG->dirroot .'/lang/'.$lang.'_utf8')) {
 575             $SESSION->lang = $lang.'_utf8';
 576         }
 577     }
 578
 579     setup_lang_from_browser();
 580
 581     unset($lang);
 582
 583     if (empty($CFG->lang)) {
 584         if (empty($SESSION->lang)) {
 585             $CFG->lang = 'en_utf8';
 586         } else {
 587             $CFG->lang = $SESSION->lang;
 588         }
 589     }
 590
 591     // set default locale and themes - might be changed again later from require_login()
 592     course_setup();
 593
 594     if (!empty($CFG->opentogoogle)) {
 595         if (empty($USER->id)) {  // Ignore anyone logged in
 596             if (!empty($_SERVER['HTTP_USER_AGENT'])) {
 597                 if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false ) {
 598                     $USER = guest_user();
 599                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'google.com') !== false ) {
 600                     $USER = guest_user();
 601                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'Yahoo! Slurp') !== false ) {
 602                     $USER = guest_user();
 603                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSNBOT') !== false ) {
 604                     $USER = guest_user();
 605                 }
 606             }
 607             if (empty($USER) && !empty($_SERVER['HTTP_REFERER'])) {
 608                 if (strpos($_SERVER['HTTP_REFERER'], 'google') !== false ) {
 609                     $USER = guest_user();
 610                 } else if (strpos($_SERVER['HTTP_REFERER'], 'altavista') !== false ) {
 611                     $USER = guest_user();
 612                 }
 613             }
 614             if (!empty($USER)) {
 615                 load_all_capabilities();
 616             }
 617         }
 618     }
 619
 620     if ($CFG->theme == 'standard' or $CFG->theme == 'standardwhite') {    // Temporary measure to help with XHTML validation
 621         if (isset($_SERVER['HTTP_USER_AGENT']) and empty($_SESSION['USER']->id)) {      // Allow W3CValidator in as user called w3cvalidator (or guest)
 622             if ((strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) or
 623                 (strpos($_SERVER['HTTP_USER_AGENT'], 'Cynthia') !== false )) {
 624                 if ($USER = get_complete_user_data("username", "w3cvalidator")) {
 625                     $USER->ignoresesskey = true;
 626                 } else {
 627                     $USER = guest_user();
 628                 }
 629             }
 630         }
 631     }
 632
 633 /// Apache log intergration. In apache conf file one can use ${MOODULEUSER}n in
 634 /// LogFormat to get the current logged in username in moodle.
 635     if ($USER && function_exists('apache_note') && !empty($CFG->apacheloguser)) {
 636         $apachelog_username = clean_filename($USER->username);
 637         $apachelog_name = clean_filename($USER->firstname. " ".$USER->lastname);
 638         $apachelog_userid = $USER->id;
 639         if (isset($USER->realuser)) {
 640             if ($realuser = get_record('user', 'id', $USER->realuser)) {
 641                 $apachelog_username = clean_filename($realuser->username." as ".$apachelog_username);
 642                 $apachelog_name = clean_filename($realuser->firstname." ".$realuser->lastname ." as ".$apachelog_name);
 643                 $apachelog_userid = clean_filename($realuser->id." as ".$apachelog_userid);
 644             }
 645         }
 646         switch ($CFG->apacheloguser) {
 647             case 3:
 648                 $logname = $apachelog_username;
 649                 break;
 650             case 2:
 651                 $logname = $apachelog_name;
 652                 break;
 653             case 1:
 654             default:
 655                 $logname = $apachelog_userid;
 656                 break;
 657         }
 658         apache_note('MOODLEUSER', $logname);
 659     }
 660
 661 /// Adjust ALLOWED_TAGS
 662     adjust_allowed_tags();
 663
 664
 665 /// Use a custom script replacement if one exists
 666     if (!empty($CFG->customscripts)) {
 667         if (($customscript = custom_script_path()) !== false) {
 668             require ($customscript);
 669         }
 670     }
 671
 672 /// note: we can not block non utf-8 installatrions here, because empty mysql database
 673 /// might be converted to utf-8 in admin/index.php during installation
 674 ?>