bootstrap.inc 63.6 KB
Newer Older
1
<?php
Dries's avatar
   
Dries committed
2
// $Id$
Dries's avatar
 
Dries committed
3

Dries's avatar
   
Dries committed
4
5
6
7
/**
 * @file
 * Functions that need to be loaded on every Drupal request.
 */
Dries's avatar
   
Dries committed
8

9
10
11
12
/**
 * Indicates that the item should never be removed unless explicitly told to
 * using cache_clear_all() with a cache ID.
 */
13
define('CACHE_PERMANENT', 0);
14
15
16
17

/**
 * Indicates that the item should be removed at the next general cache wipe.
 */
18
define('CACHE_TEMPORARY', -1);
Dries's avatar
 
Dries committed
19

20
21
22
/**
 * Indicates that page caching is disabled.
 */
23
define('CACHE_DISABLED', 0);
24
25
26
27

/**
 * Indicates that page caching is enabled, using "normal" mode.
 */
28
define('CACHE_NORMAL', 1);
29

30
/**
31
 * Log message severity -- Emergency: system is unusable.
32
 *
33
34
 * @see watchdog()
 * @see watchdog_severity_levels()
35
 */
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
define('WATCHDOG_EMERG', 0);

/**
 * Log message severity -- Alert: action must be taken immediately.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_ALERT', 1);

/**
 * Log message severity -- Critical: critical conditions.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_CRITICAL', 2);

/**
 * Log message severity -- Error: error conditions.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_ERROR', 3);

/**
 * Log message severity -- Warning: warning conditions.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_WARNING', 4);

/**
 * Log message severity -- Notice: normal but significant condition.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_NOTICE', 5);

/**
 * Log message severity -- Informational: informational messages.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_INFO', 6);

/**
 * Log message severity -- Debug: debug-level messages.
 *
 * @see watchdog()
 * @see watchdog_severity_levels()
 */
define('WATCHDOG_DEBUG', 7);
93

94
95
96
/**
 * First bootstrap phase: initialize configuration.
 */
97
define('DRUPAL_BOOTSTRAP_CONFIGURATION', 0);
98
99

/**
100
 * Second bootstrap phase: try to serve a cached page.
101
 */
102
define('DRUPAL_BOOTSTRAP_PAGE_CACHE', 1);
103
104
105
106

/**
 * Third bootstrap phase: initialize database layer.
 */
107
define('DRUPAL_BOOTSTRAP_DATABASE', 2);
108
109

/**
110
 * Fourth bootstrap phase: initialize the variable system.
111
 */
112
define('DRUPAL_BOOTSTRAP_VARIABLES', 3);
113
114

/**
115
 * Fifth bootstrap phase: initialize session handling.
116
 */
117
define('DRUPAL_BOOTSTRAP_SESSION', 4);
118
119

/**
120
 * Sixth bootstrap phase: set up the page header.
121
 */
122
define('DRUPAL_BOOTSTRAP_PAGE_HEADER', 5);
123
124

/**
125
 * Seventh bootstrap phase: find out language of the page.
126
 */
127
define('DRUPAL_BOOTSTRAP_LANGUAGE', 6);
128
129

/**
130
 * Eighth bootstrap phase: set $_GET['q'] to Drupal path of request.
131
 */
132
define('DRUPAL_BOOTSTRAP_PATH', 7);
133
134
135
136
137

/**
 * Final bootstrap phase: Drupal is fully loaded; validate and fix
 * input data.
 */
138
define('DRUPAL_BOOTSTRAP_FULL', 8);
139

140
141
142
/**
 * Role ID for anonymous users; should match what's in the "role" table.
 */
143
define('DRUPAL_ANONYMOUS_RID', 1);
144
145
146
147

/**
 * Role ID for authenticated users; should match what's in the "role" table.
 */
148
149
define('DRUPAL_AUTHENTICATED_RID', 2);

150
/**
151
 * The number of bytes in a kilobyte. For more information, visit
152
153
154
155
 * http://en.wikipedia.org/wiki/Kilobyte.
 */
define('DRUPAL_KILOBYTE', 1024);

156
157
158
159
160
161
/**
 * No language negotiation. The default language is used.
 */
define('LANGUAGE_NEGOTIATION_NONE', 0);

/**
162
163
 * Path based negotiation with fallback to default language if no defined path
 * prefix identified.
164
165
166
167
 */
define('LANGUAGE_NEGOTIATION_PATH_DEFAULT', 1);

/**
168
169
 * Path based negotiation with fallback to user preferences and browser
 * language detection if no defined path prefix identified.
170
171
172
173
 */
define('LANGUAGE_NEGOTIATION_PATH', 2);

/**
174
175
 * Domain based negotiation with fallback to default language if no language
 * identified by domain.
176
177
178
 */
define('LANGUAGE_NEGOTIATION_DOMAIN', 3);

179
180
181
182
183
184
185
186
187
188
/**
 * Language written left to right. Possible value of $language->direction.
 */
define('LANGUAGE_LTR', 0);

/**
 * Language written right to left. Possible value of $language->direction.
 */
define('LANGUAGE_RTL', 1);

189
190
191
/**
 * For convenience, define a short form of the request time global.
 */
192
define('REQUEST_TIME', $_SERVER['REQUEST_TIME']);
193

194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/**
 * @name Title text filtering flags
 * @{
 * Flags for use in drupal_set_title().
 */

/**
 * Flag for drupal_set_title(); text is not sanitized, so run check_plain().
 */
define('CHECK_PLAIN', 0);

/**
 * Flag for drupal_set_title(); text has already been sanitized.
 */
define('PASS_THROUGH', -1);

210
/**
211
 * Signals that the registry lookup cache should be reset.
212
213
214
215
 */
define('REGISTRY_RESET_LOOKUP_CACHE', 1);

/**
216
 * Signals that the registry lookup cache should be written to storage.
217
218
219
 */
define('REGISTRY_WRITE_LOOKUP_CACHE', 2);

220
221
222
223
224
/**
 * @} End of "Title text filtering flags".
 */


Dries's avatar
   
Dries committed
225
/**
226
227
 * Start the timer with the specified name. If you start and stop the same
 * timer multiple times, the measured intervals will be accumulated.
Dries's avatar
   
Dries committed
228
229
230
231
232
233
234
 *
 * @param name
 *   The name of the timer.
 */
function timer_start($name) {
  global $timers;

235
  $timers[$name]['start'] = microtime(TRUE);
236
  $timers[$name]['count'] = isset($timers[$name]['count']) ? ++$timers[$name]['count'] : 1;
Dries's avatar
   
Dries committed
237
238
239
240
241
242
243
244
245
246
247
248
249
}

/**
 * Read the current timer value without stopping the timer.
 *
 * @param name
 *   The name of the timer.
 * @return
 *   The current timer value in ms.
 */
function timer_read($name) {
  global $timers;

250
  if (isset($timers[$name]['start'])) {
251
    $stop = microtime(TRUE);
252
    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
Dries's avatar
   
Dries committed
253

254
255
256
257
    if (isset($timers[$name]['time'])) {
      $diff += $timers[$name]['time'];
    }
    return $diff;
258
  }
Dries's avatar
   
Dries committed
259
260
261
262
263
264
265
266
}

/**
 * Stop the timer with the specified name.
 *
 * @param name
 *   The name of the timer.
 * @return
267
268
 *   A timer array. The array contains the number of times the timer has been
 *   started and stopped (count) and the accumulated timer value in ms (time).
Dries's avatar
   
Dries committed
269
270
271
272
 */
function timer_stop($name) {
  global $timers;

273
  $timers[$name]['time'] = timer_read($name);
Dries's avatar
   
Dries committed
274
275
276
277
  unset($timers[$name]['start']);

  return $timers[$name];
}
278

Dries's avatar
   
Dries committed
279
/**
280
 * Find the appropriate configuration directory.
Dries's avatar
   
Dries committed
281
 *
282
283
 * Try finding a matching configuration directory by stripping the website's
 * hostname from left to right and pathname from right to left. The first
284
 * configuration file found will be used; the remaining will ignored. If no
285
 * configuration file is found, return a default value '$confdir/default'.
Dries's avatar
Dries committed
286
 *
287
 * Example for a fictitious site installed at
288
289
 * http://www.drupal.org:8080/mysite/test/ the 'settings.php' is searched in
 * the following directories:
Dries's avatar
   
Dries committed
290
 *
291
292
293
294
 *  1. $confdir/8080.www.drupal.org.mysite.test
 *  2. $confdir/www.drupal.org.mysite.test
 *  3. $confdir/drupal.org.mysite.test
 *  4. $confdir/org.mysite.test
Dries's avatar
   
Dries committed
295
 *
296
297
298
299
 *  5. $confdir/8080.www.drupal.org.mysite
 *  6. $confdir/www.drupal.org.mysite
 *  7. $confdir/drupal.org.mysite
 *  8. $confdir/org.mysite
Dries's avatar
   
Dries committed
300
 *
301
302
303
304
 *  9. $confdir/8080.www.drupal.org
 * 10. $confdir/www.drupal.org
 * 11. $confdir/drupal.org
 * 12. $confdir/org
Dries's avatar
   
Dries committed
305
 *
306
 * 13. $confdir/default
307
 *
308
 * If a file named sites.php is present in the $confdir, it will be loaded
309
310
 * prior to scanning for directories. It should define an associative array
 * named $sites, which maps domains to directories. It should be in the form
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
 * of:
 *
 * $sites = array(
 *   'The url to alias' => 'A directory within the sites directory'
 * );
 *
 * For example:
 *
 * $sites = array(
 *   'devexample.com' => 'example.com',
 *   'localhost/example' => 'example.com',
 * );
 *
 * The above array will cause Drupal to look for a directory named
 * "example.com" in the sites directory whenever a request comes from
 * "example.com", "devexample.com", or "localhost/example". That is useful
 * on development servers, where the domain name may not be the same as the
328
 * domain of the live server. Since Drupal stores file paths into the database
329
330
331
 * (files, system table, etc.) this will ensure the paths are correct while
 * accessed on development servers.
 *
332
333
334
335
336
337
338
339
340
341
 * @param $require_settings
 *   Only configuration directories with an existing settings.php file
 *   will be recognized. Defaults to TRUE. During initial installation,
 *   this is set to FALSE so that Drupal can detect a matching directory,
 *   then create a new settings.php file in it.
 * @param reset
 *   Force a full search for matching directories even if one had been
 *   found previously.
 * @return
 *   The path of the matching directory.
Dries's avatar
   
Dries committed
342
 */
343
function conf_path($require_settings = TRUE, $reset = FALSE) {
344
  $conf = &drupal_static(__FUNCTION__, '');
Dries's avatar
 
Dries committed
345

346
  if ($conf && !$reset) {
Dries's avatar
Dries committed
347
348
    return $conf;
  }
Dries's avatar
 
Dries committed
349

Dries's avatar
   
Dries committed
350
  $confdir = 'sites';
351
352
353
354
355
356
357

  $sites = array();
  if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/sites.php')) {
    // This will overwrite $sites with the desired mappings.
    include(DRUPAL_ROOT . '/' . $confdir . '/sites.php');
  }

358
  $uri = explode('/', $_SERVER['SCRIPT_NAME'] ? $_SERVER['SCRIPT_NAME'] : $_SERVER['SCRIPT_FILENAME']);
359
  $server = explode('.', implode('.', array_reverse(explode(':', rtrim($_SERVER['HTTP_HOST'], '.')))));
Dries's avatar
Dries committed
360
361
362
  for ($i = count($uri) - 1; $i > 0; $i--) {
    for ($j = count($server); $j > 0; $j--) {
      $dir = implode('.', array_slice($server, -$j)) . implode('.', array_slice($uri, 0, $i));
363
364
365
366
      if (isset($sites[$dir]) && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $sites[$dir])) {
        $dir = $sites[$dir];
      }
      if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir . '/settings.php') || (!$require_settings && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir))) {
Dries's avatar
Dries committed
367
368
369
        $conf = "$confdir/$dir";
        return $conf;
      }
Dries's avatar
 
Dries committed
370
371
    }
  }
Dries's avatar
Dries committed
372
373
  $conf = "$confdir/default";
  return $conf;
Dries's avatar
 
Dries committed
374
375
}

376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
/**
 * Set appropriate server variables needed for command line scripts to work.
 *
 * This function can be called by command line scripts before bootstrapping
 * Drupal, to ensure that the page loads with the desired server parameters.
 * This is because many parts of Drupal assume that they are running in a web
 * browser and therefore use information from the global PHP $_SERVER variable
 * that does not get set when Drupal is run from the command line.
 *
 * In many cases, the default way in which this function populates the $_SERVER
 * variable is sufficient, and it can therefore be called without passing in
 * any input. However, command line scripts running on a multisite installation
 * (or on any installation that has settings.php stored somewhere other than
 * the sites/default folder) need to pass in the URL of the site to allow
 * Drupal to detect the correct location of the settings.php file. Passing in
 * the 'url' parameter is also required for functions like request_uri() to
 * return the expected values.
 *
 * Most other parameters do not need to be passed in, but may be necessary in
 * some cases; for example, if Drupal's ip_address() function needs to return
 * anything but the standard localhost value ('127.0.0.1'), the command line
 * script should pass in the desired value via the 'REMOTE_ADDR' key.
 *
 * @param $variables
 *   (optional) An associative array of variables within $_SERVER that should
 *   be replaced. If the special element 'url' is provided in this array, it
 *   will be used to populate some of the server defaults; it should be set to
 *   the URL of the current page request, excluding any $_GET request but
 *   including the script name (e.g., http://www.example.com/mysite/index.php).
 *
 * @see conf_path()
 * @see request_uri()
 * @see ip_address()
 */
function drupal_override_server_variables($variables = array()) {
  // Set defaults based on the provided URL.
  if (isset($variables['url'])) {
    $url = parse_url($variables['url']);
    unset($variables['url']);
  }
  else {
    $url = array();
  }
  $url += array(
    'path' => '',
    'host' => 'localhost',
  );
  $defaults = array(
    'HTTP_HOST' => $url['host'],
    'SCRIPT_NAME' => $url['path'],
    'REMOTE_ADDR' => '127.0.0.1',
    'REQUEST_METHOD' => 'GET',
    'SERVER_NAME' => NULL,
429
    'SERVER_SOFTWARE' => NULL,
430
431
432
433
434
435
    'HTTP_USER_AGENT' => NULL,
  );
  // Replace elements of the $_SERVER array, as appropriate.
  $_SERVER = $variables + $_SERVER + $defaults;
}

436
/**
437
 * Initialize PHP environment.
438
 */
439
function drupal_environment_initialize() {
440
441
  if (!isset($_SERVER['HTTP_REFERER'])) {
    $_SERVER['HTTP_REFERER'] = '';
442
  }
443
444
445
  if (!isset($_SERVER['SERVER_PROTOCOL']) || ($_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.0' && $_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.1')) {
    $_SERVER['SERVER_PROTOCOL'] = 'HTTP/1.0';
  }
446

447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
  if (isset($_SERVER['HTTP_HOST'])) {
    // As HTTP_HOST is user input, ensure it only contains characters allowed
    // in hostnames. See RFC 952 (and RFC 2181).
    // $_SERVER['HTTP_HOST'] is lowercased here per specifications.
    $_SERVER['HTTP_HOST'] = strtolower($_SERVER['HTTP_HOST']);
    if (!drupal_valid_http_host($_SERVER['HTTP_HOST'])) {
      // HTTP_HOST is invalid, e.g. if containing slashes it may be an attack.
      header($_SERVER['SERVER_PROTOCOL'] . ' 400 Bad Request');
      exit;
    }
  }
  else {
    // Some pre-HTTP/1.1 clients will not send a Host header. Ensure the key is
    // defined for E_ALL compliance.
    $_SERVER['HTTP_HOST'] = '';
462
463
  }

464
465
  // Enforce E_ALL, but allow users to set levels not part of E_ALL.
  error_reporting(E_ALL | error_reporting());
466

467
468
469
  // Override PHP settings required for Drupal to work properly.
  // sites/default/default.settings.php contains more runtime settings.
  // The .htaccess file contains settings that cannot be changed at runtime.
470

471
  // Prevent PHP from generating HTML error messages.
472
  ini_set('html_errors', 0);
473
  // Don't escape quotes when reading files from the database, disk, etc.
474
  ini_set('magic_quotes_runtime', '0');
475
476
  // Use session cookies, not transparent sessions that puts the session id in
  // the query string.
477
  ini_set('session.use_cookies', '1');
478
  ini_set('session.use_only_cookies', '1');
479
  ini_set('session.use_trans_sid', '0');
480
481
  // Don't send HTTP headers using PHP's session handler.
  ini_set('session.cache_limiter', 'none');
482
483
  // Use httponly session cookies.
  ini_set('session.cookie_httponly', '1');
484
485
}

486
/**
487
 * Validate that a hostname (for example $_SERVER['HTTP_HOST']) is safe.
488
489
490
491
 *
 * @return
 *  TRUE if only containing valid characters, or FALSE otherwise.
 */
492
493
function drupal_valid_http_host($host) {
  return preg_match('/^\[?(?:[a-zA-Z0-9-:\]_]+\.?)+$/', $host);
494
495
}

496
/**
497
498
 * Loads the configuration and sets the base URL, cookie domain, and
 * session name correctly.
499
 */
500
function drupal_settings_initialize() {
501
502
  global $base_url, $base_path, $base_root;

Dries's avatar
Dries committed
503
  // Export the following settings.php variables to the global namespace
504
  global $databases, $db_prefix, $cookie_domain, $conf, $installed_profile, $update_free_access, $db_url, $is_https, $base_secure_url, $base_insecure_url;
Dries's avatar
Dries committed
505
506
  $conf = array();

507
508
  if (file_exists(DRUPAL_ROOT . '/' . conf_path() . '/settings.php')) {
    include_once DRUPAL_ROOT . '/' . conf_path() . '/settings.php';
509
  }
510
511
512
513

  if (isset($base_url)) {
    // Parse fixed base URL from settings.php.
    $parts = parse_url($base_url);
514
    $http_protocol = $parts['scheme'];
515
516
517
    if (!isset($parts['path'])) {
      $parts['path'] = '';
    }
518
    $base_path = $parts['path'] . '/';
519
520
521
522
523
    // Build $base_root (everything until first slash after "scheme://").
    $base_root = substr($base_url, 0, strlen($base_url) - strlen($parts['path']));
  }
  else {
    // Create base URL
524
525
    $http_protocol = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') ? 'https' : 'http';
    $base_root = $http_protocol . '://' . $_SERVER['HTTP_HOST'];
526

527
    $base_url = $base_root;
528
529
530
531

    // $_SERVER['SCRIPT_NAME'] can, in contrast to $_SERVER['PHP_SELF'], not
    // be modified by a visitor.
    if ($dir = trim(dirname($_SERVER['SCRIPT_NAME']), '\,/')) {
532
533
534
535
536
537
538
539
      $base_path = "/$dir";
      $base_url .= $base_path;
      $base_path .= '/';
    }
    else {
      $base_path = '/';
    }
  }
540
541
542
  $is_https = $http_protocol == 'https';
  $base_secure_url = str_replace('http://', 'https://', $base_url);
  $base_insecure_url = str_replace('https://', 'http://', $base_url);
543
544
545
546
547
548

  if ($cookie_domain) {
    // If the user specifies the cookie domain, also use it for session name.
    $session_name = $cookie_domain;
  }
  else {
549
550
551
    // Otherwise use $base_url as session name, without the protocol
    // to use the same session identifiers across http and https.
    list( , $session_name) = explode('://', $base_url, 2);
552
    // We escape the hostname because it can be modified by a visitor.
553
    if (!empty($_SERVER['HTTP_HOST'])) {
554
      $cookie_domain = check_plain($_SERVER['HTTP_HOST']);
555
556
557
558
559
560
561
    }
  }
  // Strip leading periods, www., and port numbers from cookie domain.
  $cookie_domain = ltrim($cookie_domain, '.');
  if (strpos($cookie_domain, 'www.') === 0) {
    $cookie_domain = substr($cookie_domain, 4);
  }
562
  $cookie_domain = explode(':', $cookie_domain);
563
  $cookie_domain = '.' . $cookie_domain[0];
564
565
566
567
568
  // Per RFC 2109, cookie domains must contain at least one dot other than the
  // first. For hosts such as 'localhost' or IP Addresses we don't set a cookie domain.
  if (count(explode('.', $cookie_domain)) > 2 && !is_numeric(str_replace('.', '', $cookie_domain))) {
    ini_set('session.cookie_domain', $cookie_domain);
  }
569
570
571
572
573
574
575
576
577
578
579
  // To prevent session cookies from being hijacked, a user can configure the
  // SSL version of their website to only transfer session cookies via SSL by
  // using PHP's session.cookie_secure setting. The browser will then use two
  // separate session cookies for the HTTPS and HTTP versions of the site. So we
  // must use different session identifiers for HTTPS and HTTP to prevent a
  // cookie collision.
  if ($is_https) {
    ini_set('session.cookie_secure', TRUE);
  }
  $prefix = ini_get('session.cookie_secure') ? 'SSESS' : 'SESS';
  session_name($prefix . md5($session_name));
580
581
}

Dries's avatar
Dries committed
582
583
/**
 * Returns and optionally sets the filename for a system item (module,
584
 * theme, etc.). The filename, whether provided, cached, or retrieved
Dries's avatar
Dries committed
585
586
 * from the database, is only returned if the file exists.
 *
Dries's avatar
Dries committed
587
588
589
590
591
592
593
594
595
596
597
598
 * This function plays a key role in allowing Drupal's resources (modules
 * and themes) to be located in different places depending on a site's
 * configuration. For example, a module 'foo' may legally be be located
 * in any of these three places:
 *
 * modules/foo/foo.module
 * sites/all/modules/foo/foo.module
 * sites/example.com/modules/foo/foo.module
 *
 * Calling drupal_get_filename('module', 'foo') will give you one of
 * the above, depending on where the module is located.
 *
Dries's avatar
Dries committed
599
600
601
602
603
604
605
606
607
608
609
 * @param $type
 *   The type of the item (i.e. theme, theme_engine, module).
 * @param $name
 *   The name of the item for which the filename is requested.
 * @param $filename
 *   The filename of the item if it is to be set explicitly rather
 *   than by consulting the database.
 *
 * @return
 *   The filename of the requested item.
 */
Dries's avatar
Dries committed
610
function drupal_get_filename($type, $name, $filename = NULL) {
611
  $files = &drupal_static(__FUNCTION__, array());
Dries's avatar
Dries committed
612

613
  if (!isset($files[$type])) {
Dries's avatar
Dries committed
614
615
616
    $files[$type] = array();
  }

617
  if (!empty($filename) && file_exists($filename)) {
Dries's avatar
Dries committed
618
619
    $files[$type][$name] = $filename;
  }
620
  elseif (isset($files[$type][$name])) {
Dries's avatar
Dries committed
621
622
    // nothing
  }
Dries's avatar
Dries committed
623
  // Verify that we have an active database connection, before querying
624
  // the database. This is required because this function is called both
Dries's avatar
Dries committed
625
626
  // before we have a database connection (i.e. during installation) and
  // when a database connection fails.
Dries's avatar
Dries committed
627
  else {
628
629
    try {
      $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type))->fetchField();
Dries's avatar
Dries committed
630
631
      if (file_exists($file)) {
        $files[$type][$name] = $file;
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
      }
    }
    catch (PDOException $e) {
      // The database table may not exist because Drupal is not yet installed,
      // or the database might be down. We have a fallback for this case so we
      // hide the error completely.
    }
    // Fallback to searching the filesystem if the database could not find the
    // file or the file returned by the database is not found.
    if (!isset($files[$type][$name])) {
      // We have a consistent directory naming: modules, themes...
      $dir = $type . 's';
      if ($type == 'theme_engine') {
        $dir = 'themes/engines';
        $mask = "/$name\.engine$/";
      }
      elseif ($type == 'theme') {
        $mask = "/$name\.info$/";
      }
      else {
        $mask = "/$name\.$type$/";
      }

655
      if (function_exists('drupal_system_listing')) {
656
        $matches = drupal_system_listing($mask, $dir, 'name', 0);
657
658
        if (!empty($matches[$name]->uri)) {
          $files[$type][$name] = $matches[$name]->uri;
659
        }
Dries's avatar
Dries committed
660
661
662
663
      }
    }
  }

664
665
666
  if (isset($files[$type][$name])) {
    return $files[$type][$name];
  }
Dries's avatar
Dries committed
667
668
}

Dries's avatar
   
Dries committed
669
670
671
672
673
674
675
/**
 * Load the persistent variable table.
 *
 * The variable table is composed of values that have been saved in the table
 * with variable_set() as well as those explicitly specified in the configuration
 * file.
 */
676
function variable_initialize($conf = array()) {
677
  // NOTE: caching the variables improves performance by 20% when serving cached pages.
678
  if ($cached = cache_get('variables', 'cache')) {
679
    $variables = $cached->data;
Dries's avatar
   
Dries committed
680
681
  }
  else {
682
    $variables = array_map('unserialize', db_query('SELECT name, value FROM {variable}')->fetchAllKeyed());
683
    cache_set('variables', $variables);
Dries's avatar
   
Dries committed
684
685
686
687
  }

  foreach ($conf as $name => $value) {
    $variables[$name] = $value;
Dries's avatar
 
Dries committed
688
689
  }

Dries's avatar
   
Dries committed
690
  return $variables;
Dries's avatar
 
Dries committed
691
692
}

Dries's avatar
   
Dries committed
693
694
695
696
697
698
699
700
701
/**
 * Return a persistent variable.
 *
 * @param $name
 *   The name of the variable to return.
 * @param $default
 *   The default value to use if this variable has never been set.
 * @return
 *   The value of the variable.
702
703
 *
 * @see variable_del(), variable_set()
Dries's avatar
   
Dries committed
704
 */
705
function variable_get($name, $default = NULL) {
Dries's avatar
 
Dries committed
706
707
708
709
710
  global $conf;

  return isset($conf[$name]) ? $conf[$name] : $default;
}

Dries's avatar
   
Dries committed
711
712
713
714
715
716
717
718
/**
 * Set a persistent variable.
 *
 * @param $name
 *   The name of the variable to set.
 * @param $value
 *   The value to set. This can be any PHP data type; these functions take care
 *   of serialization as necessary.
719
720
 *
 * @see variable_del(), variable_get()
Dries's avatar
   
Dries committed
721
 */
Dries's avatar
 
Dries committed
722
723
724
function variable_set($name, $value) {
  global $conf;

725
  db_merge('variable')->key(array('name' => $name))->fields(array('value' => serialize($value)))->execute();
Dries's avatar
   
Dries committed
726

727
  cache_clear_all('variables', 'cache');
Dries's avatar
 
Dries committed
728
729
730
731

  $conf[$name] = $value;
}

Dries's avatar
   
Dries committed
732
733
734
735
736
/**
 * Unset a persistent variable.
 *
 * @param $name
 *   The name of the variable to undefine.
737
738
 *
 * @see variable_get(), variable_set()
Dries's avatar
   
Dries committed
739
 */
Dries's avatar
 
Dries committed
740
function variable_del($name) {
Dries's avatar
Dries committed
741
742
  global $conf;

743
744
745
  db_delete('variable')
    ->condition('name', $name)
    ->execute();
746
  cache_clear_all('variables', 'cache');
Dries's avatar
 
Dries committed
747

Dries's avatar
Dries committed
748
  unset($conf[$name]);
Dries's avatar
 
Dries committed
749
750
}

Dries's avatar
   
Dries committed
751
752
753
/**
 * Retrieve the current page from the cache.
 *
754
755
756
757
758
759
 * Note: we do not serve cached pages to authenticated users, or to anonymous
 * users when $_SESSION is non-empty. $_SESSION may contain status messages
 * from a form submission, the contents of a shopping cart, or other user-
 * specific content that should not be cached and displayed to other users.
 *
 * @return
760
 *   The cache object, if the page was found in the cache, NULL otherwise.
Dries's avatar
   
Dries committed
761
 */
762
763
function drupal_page_get_cache() {
  global $base_root;
Dries's avatar
 
Dries committed
764

765
766
  if (drupal_page_is_cacheable()) {
    return cache_get($base_root . request_uri(), 'cache_page');
767
  }
768
769
770
771
772
773
774
775
776
777
778
779
780
781
}

/**
 * Determine the cacheability of the current page.
 *
 * @param $allow_caching
 *  Set to FALSE if you want to prevent this page to get cached.
 * @return
 *  TRUE if the current page can be cached, FALSE otherwise.
 */
function drupal_page_is_cacheable($allow_caching = NULL) {
  $allow_caching_static = &drupal_static(__FUNCTION__, TRUE);
  if (isset($allow_caching)) {
    $allow_caching_static = $allow_caching;
Dries's avatar
 
Dries committed
782
  }
783
784

  return $allow_caching_static && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')
785
    && !drupal_is_cli();
Dries's avatar
 
Dries committed
786
787
}

788
789
790
791
792
793
794
795
796
797
798
799
800
/**
 * Call all init or exit hooks without including all modules.
 *
 * @param $hook
 *   The name of the bootstrap hook we wish to invoke.
 */
function bootstrap_invoke_all($hook) {
  foreach (module_list(TRUE, TRUE) as $module) {
    drupal_load('module', $module);
    module_invoke($module, $hook);
  }
}

Dries's avatar
Dries committed
801
/**
802
 * Includes a file with the provided type and name. This prevents
Dries's avatar
Dries committed
803
804
805
806
807
808
809
810
811
812
813
 * including a theme, engine, module, etc., more than once.
 *
 * @param $type
 *   The type of item to load (i.e. theme, theme_engine, module).
 * @param $name
 *   The name of the item to load.
 *
 * @return
 *   TRUE if the item is loaded or has already been loaded.
 */
function drupal_load($type, $name) {
814
  $files = &drupal_static(__FUNCTION__, array());
Dries's avatar
Dries committed
815

816
  if (isset($files[$type][$name])) {
Dries's avatar
Dries committed
817
818
819
820
821
822
    return TRUE;
  }

  $filename = drupal_get_filename($type, $name);

  if ($filename) {
823
    include_once DRUPAL_ROOT . '/' . $filename;
Dries's avatar
Dries committed
824
825
826
827
828
829
830
831
    $files[$type][$name] = TRUE;

    return TRUE;
  }

  return FALSE;
}

832
833
834
835
836
837
838
839
840
841
842
843
844
845
/**
 * Set an HTTP response header for the current page.
 *
 * Note: When sending a Content-Type header, always include a 'charset' type,
 * too. This is necessary to avoid security bugs (e.g. UTF-7 XSS).
 *
 * @param $name
 *   The HTTP header name, or a status code followed by a reason phrase, e.g.
 *   "404 Not Found".
 * @param $value
 *   The HTTP header value; if omitted, the specified header is unset.
 * @param $append
 *   Whether to append the value to an existing header or to replace it.
 */
846
function drupal_add_http_header($name = NULL, $value = NULL, $append = FALSE) {
847
848
849
850
851
852
853
854
855
856
  // The headers as name/value pairs.
  $headers = &drupal_static(__FUNCTION__, array());

  if (!isset($name)) {
    return $headers;
  }

  // Save status codes using the special key ":status".
  if (preg_match('/^\d{3} /', $name)) {
    $value = $name;
857
    $name = $name_lower = ':status';
858
859
  }
  else {
860
    $name_lower = strtolower($name);
861
  }
862
  _drupal_set_preferred_header_name($name);
863
864

  if (!isset($value)) {
865
    $headers[$name_lower] = FALSE;
866
  }
867
  elseif (isset($headers[$name_lower]) && $append) {
868
869
    // Multiple headers with identical names may be combined using comma (RFC
    // 2616, section 4.2).
870
    $headers[$name_lower] .= ',' . $value;
871
872
  }
  else {
873
    $headers[$name_lower] = $value;
874
  }
875
  drupal_send_headers(array($name => $headers[$name_lower]), TRUE);
876
877
878
879
880
881
882
883
884
885
886
887
}

/**
 * Get the HTTP response headers for the current page.
 *
 * @param $name
 *   An HTTP header name. If omitted, all headers are returned as name/value
 *   pairs. If an array value is FALSE, the header has been unset.
 * @return
 *   A string containing the header value, or FALSE if the header has been set,
 *   or NULL if the header has not been set.
 */
888
889
function drupal_get_http_header($name = NULL) {
  $headers = drupal_add_http_header();
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
  if (isset($name)) {
    $name = strtolower($name);
    return isset($headers[$name]) ? $headers[$name] : NULL;
  }
  else {
    return $headers;
  }
}

/**
 * Header names are case-insensitive, but for maximum compatibility they should
 * follow "common form" (see RFC 2617, section 4.2).
 */
function _drupal_set_preferred_header_name($name = NULL) {
  static $header_names = array();

  if (!isset($name)) {
    return $header_names;
  }
  $header_names[strtolower($name)] = $name;
}

/**
913
 * Send the HTTP response headers previously set using drupal_add_http_header().
914
 * Add default headers, unless they have been replaced or unset using
915
 * drupal_add_http_header().
916
917
918
919
920
921
922
923
 *
 * @param $default_headers
 *   An array of headers as name/value pairs.
 * @param $single
 *   If TRUE and headers have already be sent, send only the specified header.
 */
function drupal_send_headers($default_headers = array(), $only_default = FALSE) {
  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
924
  $headers = drupal_get_http_header();
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
  if ($only_default && $headers_sent) {
    $headers = array();
  }
  $headers_sent = TRUE;

  $header_names = _drupal_set_preferred_header_name();
  foreach ($default_headers as $name => $value) {
    $name_lower = strtolower($name);
    if (!isset($headers[$name_lower])) {
      $headers[$name_lower] = $value;
      $header_names[$name_lower] = $name;
    }
  }
  foreach ($headers as $name_lower => $value) {
    if ($name_lower == ':status') {
      header($_SERVER['SERVER_PROTOCOL'] . ' ' . $value);
    }
    // Skip headers that have been unset.
    elseif ($value) {
      header($header_names[$name_lower] . ': ' . $value);
    }
  }
}

Dries's avatar
   
Dries committed
949
950
/**
 * Set HTTP headers in preparation for a page response.
951
 *
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
 * Authenticated users are always given a 'no-cache' header, and will fetch a
 * fresh page on every request. This prevents authenticated users from seeing
 * locally cached pages.
 *
 * Also give each page a unique ETag. This will force clients to include both
 * an If-Modified-Since header and an If-None-Match header when doing
 * conditional requests for the page (required by RFC 2616, section 13.3.4),
 * making the validation more robust. This is a workaround for a bug in Mozilla
 * Firefox that is triggered when Drupal's caching is enabled and the user
 * accesses Drupal via an HTTP proxy (see
 * https://bugzilla.mozilla.org/show_bug.cgi?id=269303): When an authenticated
 * user requests a page, and then logs out and requests the same page again,
 * Firefox may send a conditional request based on the page that was cached
 * locally when the user was logged in. If this page did not have an ETag
 * header, the request only contains an If-Modified-Since header. The date will
 * be recent, because with authenticated users the Last-Modified header always
 * refers to the time of the request. If the user accesses Drupal via a proxy
 * server, and the proxy already has a cached copy of the anonymous page with an
 * older Last-Modified date, the proxy may respond with 304 Not Modified, making
 * the client think that the anonymous and authenticated pageviews are
 * identical.
973
 *
974
 * @see drupal_page_set_cache()
Dries's avatar
   
Dries committed
975
 */
Dries's avatar
 
Dries committed
976
function drupal_page_header() {
977
978
979
980
981
982
983
984
985
986
987
988
989
  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
  if ($headers_sent) {
    return TRUE;
  }
  $headers_sent = TRUE;

  $default_headers = array(
    'Expires' => 'Sun, 19 Nov 1978 05:00:00 GMT',
    'Last-Modified' => gmdate(DATE_RFC1123, REQUEST_TIME),
    'Cache-Control' => 'no-cache, must-revalidate, post-check=0, pre-check=0',
    'ETag' => '"' . REQUEST_TIME . '"',
  );
  drupal_send_headers($default_headers);
990
}
Dries's avatar
   
Dries committed
991

992
993
994
/**
 * Set HTTP headers in preparation for a cached page response.
 *
995
996
 * The headers allow as much as possible in proxies and browsers without any
 * particular knowledge about the pages. Modules can override these headers
997
 * using drupal_add_http_header().
998
 *
999
1000
 * If the request is conditional (using If-Modified-Since and If-None-Match),
 * and the conditions match those currently in the cache, a 304 Not Modified