Y5Rb0ADX

1    <?php
2
3/**
4 * @file
5 * Functions that need to be loaded on every Drupal request.
6 */
7
8/**
9 * The current system version.
10 */
11define('VERSION', '7.37');
12
13/**
14 * Core API compatibility.
15 */
16define('DRUPAL_CORE_COMPATIBILITY', '7.x');
17
18/**
19 * Minimum supported version of PHP.
20 */
21define('DRUPAL_MINIMUM_PHP', '5.2.4');
22
23/**
24 * Minimum recommended value of PHP memory_limit.
25 */
26define('DRUPAL_MINIMUM_PHP_MEMORY_LIMIT', '32M');
27
28/**
29 * Error reporting level: display no errors.
30 */
31define('ERROR_REPORTING_HIDE', 0);
32
33/**
34 * Error reporting level: display errors and warnings.
35 */
36define('ERROR_REPORTING_DISPLAY_SOME', 1);
37
38/**
39 * Error reporting level: display all messages.
40 */
41define('ERROR_REPORTING_DISPLAY_ALL', 2);
42
43/**
44 * Indicates that the item should never be removed unless explicitly selected.
45 *
46 * The item may be removed using cache_clear_all() with a cache ID.
47 */
48define('CACHE_PERMANENT', 0);
49
50/**
51 * Indicates that the item should be removed at the next general cache wipe.
52 */
53define('CACHE_TEMPORARY', -1);
54
55/**
56 * @defgroup logging_severity_levels Logging severity levels
57 * @{
58 * Logging severity levels as defined in RFC 3164.
59 *
60 * The WATCHDOG_* constant definitions correspond to the logging severity levels
61 * defined in RFC 3164, section 4.1.1. PHP supplies predefined LOG_* constants
62 * for use in the syslog() function, but their values on Windows builds do not
63 * correspond to RFC 3164. The associated PHP bug report was closed with the
64 * comment, "And it's also not a bug, as Windows just have less log levels,"
65 * and "So the behavior you're seeing is perfectly normal."
66 *
67 * @see http://www.faqs.org/rfcs/rfc3164.html
68 * @see http://bugs.php.net/bug.php?id=18090
69 * @see http://php.net/manual/function.syslog.php
70 * @see http://php.net/manual/network.constants.php
71 * @see watchdog()
72 * @see watchdog_severity_levels()
73 */
74
75/**
76 * Log message severity -- Emergency: system is unusable.
77 */
78define('WATCHDOG_EMERGENCY', 0);
79
80/**
81 * Log message severity -- Alert: action must be taken immediately.
82 */
83define('WATCHDOG_ALERT', 1);
84
85/**
86 * Log message severity -- Critical conditions.
87 */
88define('WATCHDOG_CRITICAL', 2);
89
90/**
91 * Log message severity -- Error conditions.
92 */
93define('WATCHDOG_ERROR', 3);
94
95/**
96 * Log message severity -- Warning conditions.
97 */
98define('WATCHDOG_WARNING', 4);
99
100/**
101 * Log message severity -- Normal but significant conditions.
102 */
103define('WATCHDOG_NOTICE', 5);
104
105/**
106 * Log message severity -- Informational messages.
107 */
108define('WATCHDOG_INFO', 6);
109
110/**
111 * Log message severity -- Debug-level messages.
112 */
113define('WATCHDOG_DEBUG', 7);
114
115/**
116 * @} End of "defgroup logging_severity_levels".
117 */
118
119/**
120 * First bootstrap phase: initialize configuration.
121 */
122define('DRUPAL_BOOTSTRAP_CONFIGURATION', 0);
123
124/**
125 * Second bootstrap phase: try to serve a cached page.
126 */
127define('DRUPAL_BOOTSTRAP_PAGE_CACHE', 1);
128
129/**
130 * Third bootstrap phase: initialize database layer.
131 */
132define('DRUPAL_BOOTSTRAP_DATABASE', 2);
133
134/**
135 * Fourth bootstrap phase: initialize the variable system.
136 */
137define('DRUPAL_BOOTSTRAP_VARIABLES', 3);
138
139/**
140 * Fifth bootstrap phase: initialize session handling.
141 */
142define('DRUPAL_BOOTSTRAP_SESSION', 4);
143
144/**
145 * Sixth bootstrap phase: set up the page header.
146 */
147define('DRUPAL_BOOTSTRAP_PAGE_HEADER', 5);
148
149/**
150 * Seventh bootstrap phase: find out language of the page.
151 */
152define('DRUPAL_BOOTSTRAP_LANGUAGE', 6);
153
154/**
155 * Final bootstrap phase: Drupal is fully loaded; validate and fix input data.
156 */
157define('DRUPAL_BOOTSTRAP_FULL', 7);
158
159/**
160 * Role ID for anonymous users; should match what's in the "role" table.
161 */
162define('DRUPAL_ANONYMOUS_RID', 1);
163
164/**
165 * Role ID for authenticated users; should match what's in the "role" table.
166 */
167define('DRUPAL_AUTHENTICATED_RID', 2);
168
169/**
170 * The number of bytes in a kilobyte.
171 *
172 * For more information, visit http://en.wikipedia.org/wiki/Kilobyte.
173 */
174define('DRUPAL_KILOBYTE', 1024);
175
176/**
177 * The language code used when no language is explicitly assigned.
178 *
179 * Defined by ISO639-2 for "Undetermined".
180 */
181define('LANGUAGE_NONE', 'und');
182
183/**
184 * The type of language used to define the content language.
185 */
186define('LANGUAGE_TYPE_CONTENT', 'language_content');
187
188/**
189 * The type of language used to select the user interface.
190 */
191define('LANGUAGE_TYPE_INTERFACE', 'language');
192
193/**
194 * The type of language used for URLs.
195 */
196define('LANGUAGE_TYPE_URL', 'language_url');
197
198/**
199 * Language written left to right. Possible value of $language->direction.
200 */
201define('LANGUAGE_LTR', 0);
202
203/**
204 * Language written right to left. Possible value of $language->direction.
205 */
206define('LANGUAGE_RTL', 1);
207
208/**
209 * Time of the current request in seconds elapsed since the Unix Epoch.
210 *
211 * This differs from $_SERVER['REQUEST_TIME'], which is stored as a float
212 * since PHP 5.4.0. Float timestamps confuse most PHP functions
213 * (including date_create()).
214 *
215 * @see http://php.net/manual/reserved.variables.server.php
216 * @see http://php.net/manual/function.time.php
217 */
218define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
219
220/**
221 * Flag used to indicate that text is not sanitized, so run check_plain().
222 *
223 * @see drupal_set_title()
224 */
225define('CHECK_PLAIN', 0);
226
227/**
228 * Flag used to indicate that text has already been sanitized.
229 *
230 * @see drupal_set_title()
231 */
232define('PASS_THROUGH', -1);
233
234/**
235 * Signals that the registry lookup cache should be reset.
236 */
237define('REGISTRY_RESET_LOOKUP_CACHE', 1);
238
239/**
240 * Signals that the registry lookup cache should be written to storage.
241 */
242define('REGISTRY_WRITE_LOOKUP_CACHE', 2);
243
244/**
245 * Regular expression to match PHP function names.
246 *
247 * @see http://php.net/manual/language.functions.php
248 */
249define('DRUPAL_PHP_FUNCTION_PATTERN', '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*');
250
251/**
252 * A RFC7231 Compliant date.
253 *
254 * http://tools.ietf.org/html/rfc7231#section-7.1.1.1
255 *
256 * Example: Sun, 06 Nov 1994 08:49:37 GMT
257 */
258define('DATE_RFC7231', 'D, d M Y H:i:s \G\M\T');
259
260/**
261 * Provides a caching wrapper to be used in place of large array structures.
262 *
263 * This class should be extended by systems that need to cache large amounts
264 * of data and have it represented as an array to calling functions. These
265 * arrays can become very large, so ArrayAccess is used to allow different
266 * strategies to be used for caching internally (lazy loading, building caches
267 * over time etc.). This can dramatically reduce the amount of data that needs
268 * to be loaded from cache backends on each request, and memory usage from
269 * static caches of that same data.
270 *
271 * Note that array_* functions do not work with ArrayAccess. Systems using
272 * DrupalCacheArray should use this only internally. If providing API functions
273 * that return the full array, this can be cached separately or returned
274 * directly. However since DrupalCacheArray holds partial content by design, it
275 * should be a normal PHP array or otherwise contain the full structure.
276 *
277 * Note also that due to limitations in PHP prior to 5.3.4, it is impossible to
278 * write directly to the contents of nested arrays contained in this object.
279 * Only writes to the top-level array elements are possible. So if you
280 * previously had set $object['foo'] = array(1, 2, 'bar' => 'baz'), but later
281 * want to change the value of 'bar' from 'baz' to 'foobar', you cannot do so
282 * a targeted write like $object['foo']['bar'] = 'foobar'. Instead, you must
283 * overwrite the entire top-level 'foo' array with the entire set of new
284 * values: $object['foo'] = array(1, 2, 'bar' => 'foobar'). Due to this same
285 * limitation, attempts to create references to any contained data, nested or
286 * otherwise, will fail silently. So $var = &$object['foo'] will not throw an
287 * error, and $var will be populated with the contents of $object['foo'], but
288 * that data will be passed by value, not reference. For more information on
289 * the PHP limitation, see the note in the official PHP documentation at·
290 * http://php.net/manual/arrayaccess.offsetget.php on
291 * ArrayAccess::offsetGet().
292 *
293 * By default, the class accounts for caches where calling functions might
294 * request keys in the array that won't exist even after a cache rebuild. This
295 * prevents situations where a cache rebuild would be triggered over and over
296 * due to a 'missing' item. These cases are stored internally as a value of
297 * NULL. This means that the offsetGet() and offsetExists() methods
298 * must be overridden if caching an array where the top level values can
299 * legitimately be NULL, and where $object->offsetExists() needs to correctly
300 * return (equivalent to array_key_exists() vs. isset()). This should not
301 * be necessary in the majority of cases.
302 *
303 * Classes extending this class must override at least the
304 * resolveCacheMiss() method to have a working implementation.
305 *
306 * offsetSet() is not overridden by this class by default. In practice this
307 * means that assigning an offset via arrayAccess will only apply while the
308 * object is in scope and will not be written back to the persistent cache.
309 * This follows a similar pattern to static vs. persistent caching in
310 * procedural code. Extending classes may wish to alter this behavior, for
311 * example by overriding offsetSet() and adding an automatic call to persist().
312 *
313 * @see SchemaCache
314 */
315abstract class DrupalCacheArray implements ArrayAccess {
316
317  /**
318   * A cid to pass to cache_set() and cache_get().
319   */
320  protected $cid;
321
322  /**
323   * A bin to pass to cache_set() and cache_get().
324   */
325  protected $bin;
326
327  /**
328   * An array of keys to add to the cache at the end of the request.
329   */
330  protected $keysToPersist = array();
331
332  /**
333   * Storage for the data itself.
334   */
335  protected $storage = array();
336
337  /**
338   * Constructs a DrupalCacheArray object.
339   *
340   * @param $cid
341   *   The cid for the array being cached.
342   * @param $bin
343   *   The bin to cache the array.
344   */
345  public function __construct($cid, $bin) {
346    $this->cid = $cid;
347    $this->bin = $bin;
348
349    if ($cached = cache_get($this->cid, $this->bin)) {
350     $this->storage = $cached->data;
351    }
352  }
353
354  /**
355   * Implements ArrayAccess::offsetExists().
356   */
357  public function offsetExists($offset) {
358    return $this->offsetGet($offset) !== NULL;
359  }
360
361  /**
362   * Implements ArrayAccess::offsetGet().
363   */
364  public function offsetGet($offset) {
365    if (isset($this->storage[$offset]) || array_key_exists($offset, $this->storage)) {
366      return $this->storage[$offset];
367    }
368    else {
369      return $this->resolveCacheMiss($offset);
370    }
371  }
372
373  /**
374   * Implements ArrayAccess::offsetSet().
375   */
376  public function offsetSet($offset, $value) {
377    $this->storage[$offset] = $value;
378  }
379
380  /**
381   * Implements ArrayAccess::offsetUnset().
382   */
383  public function offsetUnset($offset) {
384    unset($this->storage[$offset]);
385  }
386
387  /**
388   * Flags an offset value to be written to the persistent cache.
389   *
390   * If a value is assigned to a cache object with offsetSet(), by default it
391   * will not be written to the persistent cache unless it is flagged with this
392   * method. This allows items to be cached for the duration of a request,
393   * without necessarily writing back to the persistent cache at the end.
394   *
395   * @param $offset
396   *   The array offset that was requested.
397   * @param $persist
398   *   Optional boolean to specify whether the offset should be persisted or
399   *   not, defaults to TRUE. When called with $persist = FALSE the offset will
400   *   be unflagged so that it will not be written at the end of the request.
401   */
402  protected function persist($offset, $persist = TRUE) {
403    $this->keysToPersist[$offset] = $persist;
404  }
405
406  /**
407   * Resolves a cache miss.
408   *
409   * When an offset is not found in the object, this is treated as a cache
410   * miss. This method allows classes implementing the interface to look up
411   * the actual value and allow it to be cached.
412   *
413   * @param $offset
414   *   The offset that was requested.
415   *
416   * @return
417   *   The value of the offset, or NULL if no value was found.
418   */
419  abstract protected function resolveCacheMiss($offset);
420
421  /**
422   * Writes a value to the persistent cache immediately.
423   *
424   * @param $data
425   *   The data to write to the persistent cache.
426   * @param $lock
427   *   Whether to acquire a lock before writing to cache.
428   */
429  protected function set($data, $lock = TRUE) {
430    // Lock cache writes to help avoid stampedes.
431    // To implement locking for cache misses, override __construct().
432    $lock_name = $this->cid . ':' . $this->bin;
433    if (!$lock || lock_acquire($lock_name)) {
434      if ($cached = cache_get($this->cid, $this->bin)) {
435        $data = $cached->data + $data;
436      }
437      cache_set($this->cid, $data, $this->bin);
438      if ($lock) {
439        lock_release($lock_name);
440      }
441    }
442  }
443
444  /**
445   * Destructs the DrupalCacheArray object.
446   */
447  public function __destruct() {
448    $data = array();
449    foreach ($this->keysToPersist as $offset => $persist) {
450      if ($persist) {
451        $data[$offset] = $this->storage[$offset];
452      }
453    }
454    if (!empty($data)) {
455      $this->set($data);
456    }
457  }
458}
459
460/**
461 * Starts the timer with the specified name.
462 *
463 * If you start and stop the same timer multiple times, the measured intervals
464 * will be accumulated.
465 *
466 * @param $name
467 *   The name of the timer.
468 */
469function timer_start($name) {
470  global $timers;
471
472  $timers[$name]['start'] = microtime(TRUE);
473  $timers[$name]['count'] = isset($timers[$name]['count']) ? ++$timers[$name]['count'] : 1;
474}
475
476/**
477 * Reads the current timer value without stopping the timer.
478 *
479 * @param $name
480 *   The name of the timer.
481 *
482 * @return
483 *   The current timer value in ms.
484 */
485function timer_read($name) {
486  global $timers;
487
488  if (isset($timers[$name]['start'])) {
489    $stop = microtime(TRUE);
490    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
491
492    if (isset($timers[$name]['time'])) {
493      $diff += $timers[$name]['time'];
494    }
495    return $diff;
496  }
497  return $timers[$name]['time'];
498}
499
500/**
501 * Stops the timer with the specified name.
502 *
503 * @param $name
504 *   The name of the timer.
505 *
506 * @return
507 *   A timer array. The array contains the number of times the timer has been
508 *   started and stopped (count) and the accumulated timer value in ms (time).
509 */
510function timer_stop($name) {
511  global $timers;
512
513  if (isset($timers[$name]['start'])) {
514    $stop = microtime(TRUE);
515    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
516    if (isset($timers[$name]['time'])) {
517      $timers[$name]['time'] += $diff;
518    }
519    else {
520      $timers[$name]['time'] = $diff;
521    }
522    unset($timers[$name]['start']);
523  }
524
525  return $timers[$name];
526}
527
528/**
529 * Returns the appropriate configuration directory.
530 *
531 * Returns the configuration path based on the site's hostname, port, and
532 * pathname. See default.settings.php for examples on how the URL is converted
533 * to a directory.
534 *
535 * @param bool $require_settings
536 *   Only configuration directories with an existing settings.php file
537 *   will be recognized. Defaults to TRUE. During initial installation,
538 *   this is set to FALSE so that Drupal can detect a matching directory,
539 *   then create a new settings.php file in it.
540 * @param bool $reset
541 *   Force a full search for matching directories even if one had been
542 *   found previously. Defaults to FALSE.
543 *
544 * @return
545 *   The path of the matching directory.
546 *
547 * @see default.settings.php
548 */
549function conf_path($require_settings = TRUE, $reset = FALSE) {
550  $conf = &drupal_static(__FUNCTION__, ');
551
552  if ($conf && !$reset) {
553    return $conf;
554  }
555
556  $confdir = 'sites';
557
558  $sites = array();
559  if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/sites.php')) {
560    // This will overwrite $sites with the desired mappings.
561    include(DRUPAL_ROOT . '/' . $confdir . '/sites.php');
562  }
563
564  $uri = explode('/', $_SERVER['SCRIPT_NAME'] ? $_SERVER['SCRIPT_NAME'] : $_SERVER['SCRIPT_FILENAME']);
565  $server = explode('.', implode('.', array_reverse(explode(':', rtrim($_SERVER['HTTP_HOST'], '.')))));
566  for ($i = count($uri) - 1; $i > 0; $i--) {
567    for ($j = count($server); $j > 0; $j--) {
568      $dir = implode('.', array_slice($server, -$j)) . implode('.', array_slice($uri, 0, $i));
569      if (isset($sites[$dir]) && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $sites[$dir])) {
570        $dir = $sites[$dir];
571      }
572      if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir . '/settings.php') || (!$require_settings && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir))) {
573        $conf = "$confdir/$dir";
574        return $conf;
575      }
576    }
577  }
578  $conf = "$confdir/default";
579  return $conf;
580}
581
582/**
583 * Sets appropriate server variables needed for command line scripts to work.
584 *
585 * This function can be called by command line scripts before bootstrapping
586 * Drupal, to ensure that the page loads with the desired server parameters.
587 * This is because many parts of Drupal assume that they are running in a web
588 * browser and therefore use information from the global PHP $_SERVER variable
589 * that does not get set when Drupal is run from the command line.
590 *
591 * In many cases, the default way in which this function populates the $_SERVER
592 * variable is sufficient, and it can therefore be called without passing in
593 * any input. However, command line scripts running on a multisite installation
594 * (or on any installation that has settings.php stored somewhere other than
595 * the sites/default folder) need to pass in the URL of the site to allow
596 * Drupal to detect the correct location of the settings.php file. Passing in
597 * the 'url' parameter is also required for functions like request_uri() to
598 * return the expected values.
599 *
600 * Most other parameters do not need to be passed in, but may be necessary in
601 * some cases; for example, if Drupal's ip_address() function needs to return
602 * anything but the standard localhost value ('127.0.0.1'), the command line
603 * script should pass in the desired value via the 'REMOTE_ADDR' key.
604 *
605 * @param $variables
606 *   (optional) An associative array of variables within $_SERVER that should
607 *   be replaced. If the special element 'url' is provided in this array, it
608 *   will be used to populate some of the server defaults; it should be set to
609 *   the URL of the current page request, excluding any $_GET request but
610 *   including the script name (e.g., http://www.example.com/mysite/index.php).
611 *
612 * @see conf_path()
613 * @see request_uri()
614 * @see ip_address()
615 */
616function drupal_override_server_variables($variables = array()) {
617  // Allow the provided URL to override any existing values in $_SERVER.
618  if (isset($variables['url'])) {
619    $url = parse_url($variables['url']);
620    if (isset($url['host'])) {
621      $_SERVER['HTTP_HOST'] = $url['host'];
622    }
623    if (isset($url['path'])) {
624      $_SERVER['SCRIPT_NAME'] = $url['path'];
625    }
626    unset($variables['url']);
627  }
628  // Define default values for $_SERVER keys. These will be used if $_SERVER
629  // does not already define them and no other values are passed in to this
630  // function.
631  $defaults = array(
632    'HTTP_HOST' => 'localhost',
633    'SCRIPT_NAME' => NULL,
634    'REMOTE_ADDR' => '127.0.0.1',
635    'REQUEST_METHOD' => 'GET',
636    'SERVER_NAME' => NULL,
637    'SERVER_SOFTWARE' => NULL,
638    'HTTP_USER_AGENT' => NULL,
639  );
640  // Replace elements of the $_SERVER array, as appropriate.
641  $_SERVER = $variables + $_SERVER + $defaults;
642}
643
644/**
645 * Initializes the PHP environment.
646 */
647function drupal_environment_initialize() {
648  if (!isset($_SERVER['HTTP_REFERER'])) {
649    $_SERVER['HTTP_REFERER'] = ';
650  }
651  if (!isset($_SERVER['SERVER_PROTOCOL']) || ($_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.0' && $_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.1')) {
652    $_SERVER['SERVER_PROTOCOL'] = 'HTTP/1.0';
653  }
654
655  if (isset($_SERVER['HTTP_HOST'])) {
656    // As HTTP_HOST is user input, ensure it only contains characters allowed
657    // in hostnames. See RFC 952 (and RFC 2181).
658    // $_SERVER['HTTP_HOST'] is lowercased here per specifications.
659    $_SERVER['HTTP_HOST'] = strtolower($_SERVER['HTTP_HOST']);
660    if (!drupal_valid_http_host($_SERVER['HTTP_HOST'])) {
661      // HTTP_HOST is invalid, e.g. if containing slashes it may be an attack.
662      header($_SERVER['SERVER_PROTOCOL'] . ' 400 Bad Request');
663      exit;
664    }
665  }
666  else {
667    // Some pre-HTTP/1.1 clients will not send a Host header. Ensure the key is
668    // defined for E_ALL compliance.
669    $_SERVER['HTTP_HOST'] = ';
670  }
671
672  // When clean URLs are enabled, emulate ?q=foo/bar using REQUEST_URI. It is
673  // not possible to append the query string using mod_rewrite without the B
674  // flag (this was added in Apache 2.2.8), because mod_rewrite unescapes the
675  // path before passing it on to PHP. This is a problem when the path contains
676  // e.g. "&" or "%" that have special meanings in URLs and must be encoded.
677  $_GET['q'] = request_path();
678
679  // Enforce E_ALL, but allow users to set levels not part of E_ALL.
680  error_reporting(E_ALL | error_reporting());
681
682  // Override PHP settings required for Drupal to work properly.
683  // sites/default/default.settings.php contains more runtime settings.
684  // The .htaccess file contains settings that cannot be changed at runtime.
685
686  // Don't escape quotes when reading files from the database, disk, etc.
687  ini_set('magic_quotes_runtime', '0');
688  // Use session cookies, not transparent sessions that puts the session id in
689  // the query string.
690  ini_set('session.use_cookies', '1');
691  ini_set('session.use_only_cookies', '1');
692  ini_set('session.use_trans_sid', '0');
693  // Don't send HTTP headers using PHP's session handler.
694  // An empty string is used here to disable the cache limiter.
695  ini_set('session.cache_limiter', ');
696  // Use httponly session cookies.
697  ini_set('session.cookie_httponly', '1');
698
699  // Set sane locale settings, to ensure consistent string, dates, times and
700  // numbers handling.
701  setlocale(LC_ALL, 'C');
702}
703
704/**
705 * Validates that a hostname (for example $_SERVER['HTTP_HOST']) is safe.
706 *
707 * @return
708 *  TRUE if only containing valid characters, or FALSE otherwise.
709 */
710function drupal_valid_http_host($host) {
711  // Limit the length of the host name to 1000 bytes to prevent DoS attacks with
712  // long host names.
713  return strlen($host) <= 1000
714    // Limit the number of subdomains and port separators to prevent DoS attacks
715    // in conf_path().
716    && substr_count($host, '.') <= 100
717    && substr_count($host, ':') <= 100
718    && preg_match('/^\[?(?:[a-zA-Z0-9-:\]_]+\.?)+$/', $host);
719}
720
721/**
722 * Sets the base URL, cookie domain, and session name from configuration.
723 */
724function drupal_settings_initialize() {
725  global $base_url, $base_path, $base_root;
726
727  // Export these settings.php variables to the global namespace.
728  global $databases, $cookie_domain, $conf, $installed_profile, $update_free_access, $db_url, $db_prefix, $drupal_hash_salt, $is_https, $base_secure_url, $base_insecure_url;
729  $conf = array();
730
731  if (file_exists(DRUPAL_ROOT . '/' . conf_path() . '/settings.php')) {
732    include_once DRUPAL_ROOT . '/' . conf_path() . '/settings.php';
733  }
734  $is_https = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on';
735
736  if (isset($base_url)) {
737    // Parse fixed base URL from settings.php.
738    $parts = parse_url($base_url);
739    if (!isset($parts['path'])) {
740      $parts['path'] = ';
741    }
742    $base_path = $parts['path'] . '/';
743    // Build $base_root (everything until first slash after "scheme://").
744    $base_root = substr($base_url, 0, strlen($base_url) - strlen($parts['path']));
745  }
746  else {
747    // Create base URL.
748    $http_protocol = $is_https ? 'https' : 'http';
749    $base_root = $http_protocol . '://' . $_SERVER['HTTP_HOST'];
750
751    $base_url = $base_root;
752
753    // $_SERVER['SCRIPT_NAME'] can, in contrast to $_SERVER['PHP_SELF'], not
754    // be modified by a visitor.
755    if ($dir = rtrim(dirname($_SERVER['SCRIPT_NAME']), '\/')) {
756      $base_path = $dir;
757      $base_url .= $base_path;
758      $base_path .= '/';
759    }
760    else {
761      $base_path = '/';
762    }
763  }
764  $base_secure_url = str_replace('http://', 'https://', $base_url);
765  $base_insecure_url = str_replace('https://', 'http://', $base_url);
766
767  if ($cookie_domain) {
768    // If the user specifies the cookie domain, also use it for session name.
769    $session_name = $cookie_domain;
770  }
771  else {
772    // Otherwise use $base_url as session name, without the protocol
773    // to use the same session identifiers across HTTP and HTTPS.
774    list( , $session_name) = explode('://', $base_url, 2);
775    // HTTP_HOST can be modified by a visitor, but we already sanitized it
776    // in drupal_settings_initialize().
777    if (!empty($_SERVER['HTTP_HOST'])) {
778      $cookie_domain = $_SERVER['HTTP_HOST'];
779      // Strip leading periods, www., and port numbers from cookie domain.
780      $cookie_domain = ltrim($cookie_domain, '.');
781      if (strpos($cookie_domain, 'www.') === 0) {
782        $cookie_domain = substr($cookie_domain, 4);
783      }
784      $cookie_domain = explode(':', $cookie_domain);
785      $cookie_domain = '.' . $cookie_domain[0];
786    }
787  }
788  // Per RFC 2109, cookie domains must contain at least one dot other than the
789  // first. For hosts such as 'localhost' or IP Addresses we don't set a cookie domain.
790  if (count(explode('.', $cookie_domain)) > 2 && !is_numeric(str_replace('.', ', $cookie_domain))) {
791    ini_set('session.cookie_domain', $cookie_domain);
792  }
793  // To prevent session cookies from being hijacked, a user can configure the
794  // SSL version of their website to only transfer session cookies via SSL by
795  // using PHP's session.cookie_secure setting. The browser will then use two
796  // separate session cookies for the HTTPS and HTTP versions of the site. So we
797  // must use different session identifiers for HTTPS and HTTP to prevent a
798  // cookie collision.
799  if ($is_https) {
800    ini_set('session.cookie_secure', TRUE);
801  }
802  $prefix = ini_get('session.cookie_secure') ? 'SSESS' : 'SESS';
803  session_name($prefix . substr(hash('sha256', $session_name), 0, 32));
804}
805
806/**
807 * Returns and optionally sets the filename for a system resource.
808 *
809 * The filename, whether provided, cached, or retrieved from the database, is
810 * only returned if the file exists.
811 *
812 * This function plays a key role in allowing Drupal's resources (modules
813 * and themes) to be located in different places depending on a site's
814 * configuration. For example, a module 'foo' may legally be located
815 * in any of these three places:
816 *
817 * modules/foo/foo.module
818 * sites/all/modules/foo/foo.module
819 * sites/example.com/modules/foo/foo.module
820 *
821 * Calling drupal_get_filename('module', 'foo') will give you one of
822 * the above, depending on where the module is located.
823 *
824 * @param $type
825 *   The type of the item (theme, theme_engine, module, profile).
826 * @param $name
827 *   The name of the item for which the filename is requested.
828 * @param $filename
829 *   The filename of the item if it is to be set explicitly rather
830 *   than by consulting the database.
831 *
832 * @return
833 *   The filename of the requested item or NULL if the item is not found.
834 */
835function drupal_get_filename($type, $name, $filename = NULL) {
836  // The location of files will not change during the request, so do not use
837  // drupal_static().
838  static $files = array(), $dirs = array();
839
840  // Profiles are a special case: they have a fixed location and naming.
841  if ($type == 'profile') {
842    $profile_filename = "profiles/$name/$name.profile";
843    $files[$type][$name] = file_exists($profile_filename) ? $profile_filename : FALSE;
844  }
845  if (!isset($files[$type])) {
846    $files[$type] = array();
847  }
848
849  if (!empty($filename) && file_exists($filename)) {
850    $files[$type][$name] = $filename;
851  }
852  elseif (isset($files[$type][$name])) {
853    // nothing
854  }
855  // Verify that we have an active database connection, before querying
856  // the database. This is required because this function is called both
857  // before we have a database connection (i.e. during installation) and
858  // when a database connection fails.
859  else {
860    try {
861      if (function_exists('db_query')) {
862        $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type))->fetchField();
863        if ($file !== FALSE && file_exists(DRUPAL_ROOT . '/' . $file)) {
864          $files[$type][$name] = $file;
865        }
866      }
867    }
868    catch (Exception $e) {
869      // The database table may not exist because Drupal is not yet installed,
870      // or the database might be down. We have a fallback for this case so we
871      // hide the error completely.
872    }
873    // Fallback to searching the filesystem if the database could not find the
874    // file or the file returned by the database is not found.
875    if (!isset($files[$type][$name])) {
876      // We have a consistent directory naming: modules, themes...
877      $dir = $type . 's';
878      if ($type == 'theme_engine') {
879        $dir = 'themes/engines';
880        $extension = 'engine';
881      }
882      elseif ($type == 'theme') {
883        $extension = 'info';
884      }
885      else {
886        $extension = $type;
887      }
888
889      if (!isset($dirs[$dir][$extension])) {
890        $dirs[$dir][$extension] = TRUE;
891        if (!function_exists('drupal_system_listing')) {
892          require_once DRUPAL_ROOT . '/includes/common.inc';
893        }
894        // Scan the appropriate directories for all files with the requested
895        // extension, not just the file we are currently looking for. This
896        // prevents unnecessary scans from being repeated when this function is
897        // called more than once in the same page request.
898        $matches = drupal_system_listing("/^" . DRUPAL_PHP_FUNCTION_PATTERN . "\.$extension$/", $dir, 'name', 0);
899        foreach ($matches as $matched_name => $file) {
900          $files[$type][$matched_name] = $file->uri;
901        }
902      }
903    }
904  }
905
906  if (isset($files[$type][$name])) {
907    return $files[$type][$name];
908  }
909}
910
911/**
912 * Loads the persistent variable table.
913 *
914 * The variable table is composed of values that have been saved in the table
915 * with variable_set() as well as those explicitly specified in the
916 * configuration file.
917 */
918function variable_initialize($conf = array()) {
919  // NOTE: caching the variables improves performance by 20% when serving
920  // cached pages.
921  if ($cached = cache_get('variables', 'cache_bootstrap')) {
922    $variables = $cached->data;
923  }
924  else {
925    // Cache miss. Avoid a stampede.
926    $name = 'variable_init';
927    if (!lock_acquire($name, 1)) {
928      // Another request is building the variable cache.
929      // Wait, then re-run this function.
930      lock_wait($name);
931      return variable_initialize($conf);
932    }
933    else {
934      // Proceed with variable rebuild.
935      $variables = array_map('unserialize', db_query('SELECT name, value FROM {variable}')->fetchAllKeyed());
936      cache_set('variables', $variables, 'cache_bootstrap');
937      lock_release($name);
938    }
939  }
940
941  foreach ($conf as $name => $value) {
942    $variables[$name] = $value;
943  }
944
945  return $variables;
946}
947
948/**
949 * Returns a persistent variable.
950 *
951 * Case-sensitivity of the variable_* functions depends on the database
952 * collation used. To avoid problems, always use lower case for persistent
953 * variable names.
954 *
955 * @param $name
956 *   The name of the variable to return.
957 * @param $default
958 *   The default value to use if this variable has never been set.
959 *
960 * @return
961 *   The value of the variable. Unserialization is taken care of as necessary.
962 *
963 * @see variable_del()
964 * @see variable_set()
965 */
966function variable_get($name, $default = NULL) {
967  global $conf;
968
969  return isset($conf[$name]) ? $conf[$name] : $default;
970}
971
972/**
973 * Sets a persistent variable.
974 *
975 * Case-sensitivity of the variable_* functions depends on the database
976 * collation used. To avoid problems, always use lower case for persistent
977 * variable names.
978 *
979 * @param $name
980 *   The name of the variable to set.
981 * @param $value
982 *   The value to set. This can be any PHP data type; these functions take care
983 *   of serialization as necessary.
984 *
985 * @see variable_del()
986 * @see variable_get()
987 */
988function variable_set($name, $value) {
989  global $conf;
990
991  db_merge('variable')->key(array('name' => $name))->fields(array('value' => serialize($value)))->execute();
992
993  cache_clear_all('variables', 'cache_bootstrap');
994
995  $conf[$name] = $value;
996}
997
998/**
999 * Unsets a persistent variable.
1000 *
1001 * Case-sensitivity of the variable_* functions depends on the database
1002 * collation used. To avoid problems, always use lower case for persistent
1003 * variable names.
1004 *
1005 * @param $name
1006 *   The name of the variable to undefine.
1007 *
1008 * @see variable_get()
1009 * @see variable_set()
1010 */
1011function variable_del($name) {
1012  global $conf;
1013
1014  db_delete('variable')
1015    ->condition('name', $name)
1016    ->execute();
1017  cache_clear_all('variables', 'cache_bootstrap');
1018
1019  unset($conf[$name]);
1020}
1021
1022/**
1023 * Retrieves the current page from the cache.
1024 *
1025 * Note: we do not serve cached pages to authenticated users, or to anonymous
1026 * users when $_SESSION is non-empty. $_SESSION may contain status messages
1027 * from a form submission, the contents of a shopping cart, or other user-
1028 * specific content that should not be cached and displayed to other users.
1029 *
1030 * @param $check_only
1031 *   (optional) Set to TRUE to only return whether a previous call found a
1032 *   cache entry.
1033 *
1034 * @return
1035 *   The cache object, if the page was found in the cache, NULL otherwise.
1036 */
1037function drupal_page_get_cache($check_only = FALSE) {
1038  global $base_root;
1039  static $cache_hit = FALSE;
1040
1041  if ($check_only) {
1042    return $cache_hit;
1043  }
1044
1045  if (drupal_page_is_cacheable()) {
1046    $cache = cache_get($base_root . request_uri(), 'cache_page');
1047    if ($cache !== FALSE) {
1048      $cache_hit = TRUE;
1049    }
1050    return $cache;
1051  }
1052}
1053
1054/**
1055 * Determines the cacheability of the current page.
1056 *
1057 * @param $allow_caching
1058 *   Set to FALSE if you want to prevent this page to get cached.
1059 *
1060 * @return
1061 *   TRUE if the current page can be cached, FALSE otherwise.
1062 */
1063function drupal_page_is_cacheable($allow_caching = NULL) {
1064  $allow_caching_static = &drupal_static(__FUNCTION__, TRUE);
1065  if (isset($allow_caching)) {
1066    $allow_caching_static = $allow_caching;
1067  }
1068
1069  return $allow_caching_static && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')
1070    && !drupal_is_cli();
1071}
1072
1073/**
1074 * Invokes a bootstrap hook in all bootstrap modules that implement it.
1075 *
1076 * @param $hook
1077 *   The name of the bootstrap hook to invoke.
1078 *
1079 * @see bootstrap_hooks()
1080 */
1081function bootstrap_invoke_all($hook) {
1082  // Bootstrap modules should have been loaded when this function is called, so
1083  // we don't need to tell module_list() to reset its internal list (and we
1084  // therefore leave the first parameter at its default value of FALSE). We
1085  // still pass in TRUE for the second parameter, though; in case this is the
1086  // first time during the bootstrap that module_list() is called, we want to
1087  // make sure that its internal cache is primed with the bootstrap modules
1088  // only.
1089  foreach (module_list(FALSE, TRUE) as $module) {
1090    drupal_load('module', $module);
1091    module_invoke($module, $hook);
1092  }
1093}
1094
1095/**
1096 * Includes a file with the provided type and name.
1097 *
1098 * This prevents including a theme, engine, module, etc., more than once.
1099 *
1100 * @param $type
1101 *   The type of item to load (i.e. theme, theme_engine, module).
1102 * @param $name
1103 *   The name of the item to load.
1104 *
1105 * @return
1106 *   TRUE if the item is loaded or has already been loaded.
1107 */
1108function drupal_load($type, $name) {
1109  // Once a file is included this can't be reversed during a request so do not
1110  // use drupal_static() here.
1111  static $files = array();
1112
1113  if (isset($files[$type][$name])) {
1114    return TRUE;
1115  }
1116
1117  $filename = drupal_get_filename($type, $name);
1118
1119  if ($filename) {
1120    include_once DRUPAL_ROOT . '/' . $filename;
1121    $files[$type][$name] = TRUE;
1122
1123    return TRUE;
1124  }
1125
1126  return FALSE;
1127}
1128
1129/**
1130 * Sets an HTTP response header for the current page.
1131 *
1132 * Note: When sending a Content-Type header, always include a 'charset' type,
1133 * too. This is necessary to avoid security bugs (e.g. UTF-7 XSS).
1134 *
1135 * @param $name
1136 *   The HTTP header name, or the special 'Status' header name.
1137 * @param $value
1138 *   The HTTP header value; if equal to FALSE, the specified header is unset.
1139 *   If $name is 'Status', this is expected to be a status code followed by a
1140 *   reason phrase, e.g. "404 Not Found".
1141 * @param $append
1142 *   Whether to append the value to an existing header or to replace it.
1143 */
1144function drupal_add_http_header($name, $value, $append = FALSE) {
1145  // The headers as name/value pairs.
1146  $headers = &drupal_static('drupal_http_headers', array());
1147
1148  $name_lower = strtolower($name);
1149  _drupal_set_preferred_header_name($name);
1150
1151  if ($value === FALSE) {
1152    $headers[$name_lower] = FALSE;
1153  }
1154  elseif (isset($headers[$name_lower]) && $append) {
1155    // Multiple headers with identical names may be combined using comma (RFC
1156    // 2616, section 4.2).
1157    $headers[$name_lower] .= ',' . $value;
1158  }
1159  else {
1160    $headers[$name_lower] = $value;
1161  }
1162  drupal_send_headers(array($name => $headers[$name_lower]), TRUE);
1163}
1164
1165/**
1166 * Gets the HTTP response headers for the current page.
1167 *
1168 * @param $name
1169 *   An HTTP header name. If omitted, all headers are returned as name/value
1170 *   pairs. If an array value is FALSE, the header has been unset.
1171 *
1172 * @return
1173 *   A string containing the header value, or FALSE if the header has been set,
1174 *   or NULL if the header has not been set.
1175 */
1176function drupal_get_http_header($name = NULL) {
1177  $headers = &drupal_static('drupal_http_headers', array());
1178  if (isset($name)) {
1179    $name = strtolower($name);
1180    return isset($headers[$name]) ? $headers[$name] : NULL;
1181  }
1182  else {
1183    return $headers;
1184  }
1185}
1186
1187/**
1188 * Sets the preferred name for the HTTP header.
1189 *
1190 * Header names are case-insensitive, but for maximum compatibility they should
1191 * follow "common form" (see RFC 2617, section 4.2).
1192 */
1193function _drupal_set_preferred_header_name($name = NULL) {
1194  static $header_names = array();
1195
1196  if (!isset($name)) {
1197    return $header_names;
1198  }
1199  $header_names[strtolower($name)] = $name;
1200}
1201
1202/**
1203 * Sends the HTTP response headers that were previously set, adding defaults.
1204 *
1205 * Headers are set in drupal_add_http_header(). Default headers are not set
1206 * if they have been replaced or unset using drupal_add_http_header().
1207 *
1208 * @param array $default_headers
1209 *   (optional) An array of headers as name/value pairs.
1210 * @param bool $only_default
1211 *   (optional) If TRUE and headers have already been sent, send only the
1212 *   specified headers.
1213 */
1214function drupal_send_headers($default_headers = array(), $only_default = FALSE) {
1215  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
1216  $headers = drupal_get_http_header();
1217  if ($only_default && $headers_sent) {
1218    $headers = array();
1219  }
1220  $headers_sent = TRUE;
1221
1222  $header_names = _drupal_set_preferred_header_name();
1223  foreach ($default_headers as $name => $value) {
1224    $name_lower = strtolower($name);
1225    if (!isset($headers[$name_lower])) {
1226      $headers[$name_lower] = $value;
1227      $header_names[$name_lower] = $name;
1228    }
1229  }
1230  foreach ($headers as $name_lower => $value) {
1231    if ($name_lower == 'status') {
1232      header($_SERVER['SERVER_PROTOCOL'] . ' ' . $value);
1233    }
1234    // Skip headers that have been unset.
1235    elseif ($value !== FALSE) {
1236      header($header_names[$name_lower] . ': ' . $value);
1237    }
1238  }
1239}
1240
1241/**
1242 * Sets HTTP headers in preparation for a page response.
1243 *
1244 * Authenticated users are always given a 'no-cache' header, and will fetch a
1245 * fresh page on every request. This prevents authenticated users from seeing
1246 * locally cached pages.
1247 *
1248 * ETag and Last-Modified headers are not set per default for authenticated
1249 * users so that browsers do not send If-Modified-Since headers from
1250 * authenticated user pages. drupal_serve_page_from_cache() will set appropriate
1251 * ETag and Last-Modified headers for cached pages.
1252 *
1253 * @see drupal_page_set_cache()
1254 */
1255function drupal_page_header() {
1256  $headers_sent = &drupal_static(__FUNCTION__, FALSE);
1257  if ($headers_sent) {
1258    return TRUE;
1259  }
1260  $headers_sent = TRUE;
1261
1262  $default_headers = array(
1263    'Expires' => 'Sun, 19 Nov 1978 05:00:00 GMT',
1264    'Cache-Control' => 'no-cache, must-revalidate, post-check=0, pre-check=0',
1265  );
1266  drupal_send_headers($default_headers);
1267}
1268
1269/**
1270 * Sets HTTP headers in preparation for a cached page response.
1271 *
1272 * The headers allow as much as possible in proxies and browsers without any
1273 * particular knowledge about the pages. Modules can override these headers
1274 * using drupal_add_http_header().
1275 *
1276 * If the request is conditional (using If-Modified-Since and If-None-Match),
1277 * and the conditions match those currently in the cache, a 304 Not Modified
1278 * response is sent.
1279 */
1280function drupal_serve_page_from_cache(stdClass $cache) {
1281  // Negotiate whether to use compression.
1282  $page_compression = !empty($cache->data['page_compressed']);
1283  $return_compressed = $page_compression && isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE;
1284
1285  // Get headers set in hook_boot(). Keys are lower-case.
1286  $hook_boot_headers = drupal_get_http_header();
1287
1288  // Headers generated in this function, that may be replaced or unset using
1289  // drupal_add_http_headers(). Keys are mixed-case.
1290  $default_headers = array();
1291
1292  foreach ($cache->data['headers'] as $name => $value) {
1293    // In the case of a 304 response, certain headers must be sent, and the
1294    // remaining may not (see RFC 2616, section 10.3.5). Do not override
1295    // headers set in hook_boot().
1296    $name_lower = strtolower($name);
1297    if (in_array($name_lower, array('content-location', 'expires', 'cache-control', 'vary')) && !isset($hook_boot_headers[$name_lower])) {
1298      drupal_add_http_header($name, $value);
1299      unset($cache->data['headers'][$name]);
1300    }
1301  }
1302
1303  // If the client sent a session cookie, a cached copy will only be served
1304  // to that one particular client due to Vary: Cookie. Thus, do not set
1305  // max-age > 0, allowing the page to be cached by external proxies, when a
1306  // session cookie is present unless the Vary header has been replaced or
1307  // unset in hook_boot().
1308  $max_age = !isset($_COOKIE[session_name()]) || isset($hook_boot_headers['vary']) ? variable_get('page_cache_maximum_age', 0) : 0;
1309  $default_headers['Cache-Control'] = 'public, max-age=' . $max_age;
1310
1311  // Entity tag should change if the output changes.
1312  $etag = '"' . $cache->created . '-' . intval($return_compressed) . '"';
1313  header('Etag: ' . $etag);
1314
1315  // See if the client has provided the required HTTP headers.
1316  $if_modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) : FALSE;
1317  $if_none_match = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : FALSE;
1318
1319  if ($if_modified_since && $if_none_match
1320      && $if_none_match == $etag // etag must match
1321      && $if_modified_since == $cache->created) {  // if-modified-since must match
1322    header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified');
1323    drupal_send_headers($default_headers);
1324    return;
1325  }
1326
1327  // Send the remaining headers.
1328  foreach ($cache->data['headers'] as $name => $value) {
1329    drupal_add_http_header($name, $value);
1330  }
1331
1332  $default_headers['Last-Modified'] = gmdate(DATE_RFC7231, $cache->created);
1333
1334  // HTTP/1.0 proxies does not support the Vary header, so prevent any caching
1335  // by sending an Expires date in the past. HTTP/1.1 clients ignores the
1336  // Expires header if a Cache-Control: max-age= directive is specified (see RFC
1337  // 2616, section 14.9.3).
1338  $default_headers['Expires'] = 'Sun, 19 Nov 1978 05:00:00 GMT';
1339
1340  drupal_send_headers($default_headers);
1341
1342  // Allow HTTP proxies to cache pages for anonymous users without a session
1343  // cookie. The Vary header is used to indicates the set of request-header
1344  // fields that fully determines whether a cache is permitted to use the
1345  // response to reply to a subsequent request for a given URL without
1346  // revalidation. If a Vary header has been set in hook_boot(), it is assumed
1347  // that the module knows how to cache the page.
1348  if (!isset($hook_boot_headers['vary']) && !variable_get('omit_vary_cookie')) {
1349    header('Vary: Cookie');
1350  }
1351
1352  if ($page_compression) {
1353    header('Vary: Accept-Encoding', FALSE);
1354    // If page_compression is enabled, the cache contains gzipped data.
1355    if ($return_compressed) {
1356      // $cache->data['body'] is already gzip'ed, so make sure
1357      // zlib.output_compression does not compress it once more.
1358      ini_set('zlib.output_compression', '0');
1359      header('Content-Encoding: gzip');
1360    }
1361    else {
1362      // The client does not support compression, so unzip the data in the
1363      // cache. Strip the gzip header and run uncompress.
1364      $cache->data['body'] = gzinflate(substr(substr($cache->data['body'], 10), 0, -8));
1365    }
1366  }
1367
1368  // Print the page.
1369  print $cache->data['body'];
1370}
1371
1372/**
1373 * Defines the critical hooks that force modules to always be loaded.
1374 */
1375function bootstrap_hooks() {
1376  return array('boot', 'exit', 'watchdog', 'language_init');
1377}
1378
1379/**
1380 * Unserializes and appends elements from a serialized string.
1381 *
1382 * @param $obj
1383 *   The object to which the elements are appended.
1384 * @param $field
1385 *   The attribute of $obj whose value should be unserialized.
1386 */
1387function drupal_unpack($obj, $field = 'data') {
1388  if ($obj->$field && $data = unserialize($obj->$field)) {
1389    foreach ($data as $key => $value) {
1390      if (!empty($key) && !isset($obj->$key)) {
1391        $obj->$key = $value;
1392      }
1393    }
1394  }
1395  return $obj;
1396}
1397
1398/**
1399 * Translates a string to the current language or to a given language.
1400 *
1401 * The t() function serves two purposes. First, at run-time it translates
1402 * user-visible text into the appropriate language. Second, various mechanisms
1403 * that figure out what text needs to be translated work off t() -- the text
1404 * inside t() calls is added to the database of strings to be translated.
1405 * These strings are expected to be in English, so the first argument should
1406 * always be in English. To enable a fully-translatable site, it is important
1407 * that all human-readable text that will be displayed on the site or sent to
1408 * a user is passed through the t() function, or a related function. See the
1409 * @link http://drupal.org/node/322729 Localization API @endlink pages for
1410 * more information, including recommendations on how to break up or not
1411 * break up strings for translation.
1412 *
1413 * @section sec_translating_vars Translating Variables
1414 * You should never use t() to translate variables, such as calling
1415 * @code t($text); @endcode, unless the text that the variable holds has been
1416 * passed through t() elsewhere (e.g., $text is one of several translated
1417 * literal strings in an array). It is especially important never to call
1418 * @code t($user_text); @endcode, where $user_text is some text that a user
1419 * entered - doing that can lead to cross-site scripting and other security
1420 * problems. However, you can use variable substitution in your string, to put
1421 * variable text such as user names or link URLs into translated text. Variable
1422 * substitution looks like this:
1423 * @code
1424 * $text = t("@name's blog", array('@name' => format_username($account)));
1425 * @endcode
1426 * Basically, you can put variables like @name into your string, and t() will
1427 * substitute their sanitized values at translation time. (See the
1428 * Localization API pages referenced above and the documentation of
1429 * format_string() for details about how to define variables in your string.)
1430 * Translators can then rearrange the string as necessary for the language
1431 * (e.g., in Spanish, it might be "blog de @name").
1432 *
1433 * @section sec_alt_funcs_install Use During Installation Phase
1434 * During the Drupal installation phase, some resources used by t() wil not be
1435 * available to code that needs localization. See st() and get_t() for
1436 * alternatives.
1437 *
1438 * @param $string
1439 *   A string containing the English string to translate.
1440 * @param $args
1441 *   An associative array of replacements to make after translation. Based
1442 *   on the first character of the key, the value is escaped and/or themed.
1443 *   See format_string() for details.
1444 * @param $options
1445 *   An associative array of additional options, with the following elements:
1446 *   - 'langcode' (defaults to the current language): The language code to
1447 *     translate to a language other than what is used to display the page.
1448 *   - 'context' (defaults to the empty context): The context the source string
1449 *     belongs to.
1450 *
1451 * @return
1452 *   The translated string.
1453 *
1454 * @see st()
1455 * @see get_t()
1456 * @see format_string()
1457 * @ingroup sanitization
1458 */
1459function t($string, array $args = array(), array $options = array()) {
1460  global $language;
1461  static $custom_strings;
1462
1463  // Merge in default.
1464  if (empty($options['langcode'])) {
1465    $options['langcode'] = isset($language->language) ? $language->language : 'en';
1466  }
1467  if (empty($options['context'])) {
1468    $options['context'] = ';
1469  }
1470
1471  // First, check for an array of customized strings. If present, use the array
1472  // *instead of* database lookups. This is a high performance way to provide a
1473  // handful of string replacements. See settings.php for examples.
1474  // Cache the $custom_strings variable to improve performance.
1475  if (!isset($custom_strings[$options['langcode']])) {
1476    $custom_strings[$options['langcode']] = variable_get('locale_custom_strings_' . $options['langcode'], array());
1477  }
1478  // Custom strings work for English too, even if locale module is disabled.
1479  if (isset($custom_strings[$options['langcode']][$options['context']][$string])) {
1480    $string = $custom_strings[$options['langcode']][$options['context']][$string];
1481  }
1482  // Translate with locale module if enabled.
1483  elseif ($options['langcode'] != 'en' && function_exists('locale')) {
1484    $string = locale($string, $options['context'], $options['langcode']);
1485  }
1486  if (empty($args)) {
1487    return $string;
1488  }
1489  else {
1490    return format_string($string, $args);
1491  }
1492}
1493
1494/**
1495 * Formats a string for HTML display by replacing variable placeholders.
1496 *
1497 * This function replaces variable placeholders in a string with the requested
1498 * values and escapes the values so they can be safely displayed as HTML. It
1499 * should be used on any unknown text that is intended to be printed to an HTML
1500 * page (especially text that may have come from untrusted users, since in that
1501 * case it prevents cross-site scripting and other security problems).
1502 *
1503 * In most cases, you should use t() rather than calling this function
1504 * directly, since it will translate the text (on non-English-only sites) in
1505 * addition to formatting it.
1506 *
1507 * @param $string
1508 *   A string containing placeholders.
1509 * @param $args
1510 *   An associative array of replacements to make. Occurrences in $string of
1511 *   any key in $args are replaced with the corresponding value, after optional
1512 *   sanitization and formatting. The type of sanitization and formatting
1513 *   depends on the first character of the key:
1514 *   - @variable: Escaped to HTML using check_plain(). Use this as the default
1515 *     choice for anything displayed on a page on the site.
1516 *   - %variable: Escaped to HTML and formatted using drupal_placeholder(),
1517 *     which makes it display as <em>emphasized</em> text.
1518 *   - !variable: Inserted as is, with no sanitization or formatting. Only use
1519 *     this for text that has already been prepared for HTML display (for
1520 *     example, user-supplied text that has already been run through
1521 *     check_plain() previously, or is expected to contain some limited HTML
1522 *     tags and has already been run through filter_xss() previously).
1523 *
1524 * @see t()
1525 * @ingroup sanitization
1526 */
1527function format_string($string, array $args = array()) {
1528  // Transform arguments before inserting them.
1529  foreach ($args as $key => $value) {
1530    switch ($key[0]) {
1531      case '@':
1532        // Escaped only.
1533        $args[$key] = check_plain($value);
1534        break;
1535
1536      case '%':
1537      default:
1538        // Escaped and placeholder.
1539        $args[$key] = drupal_placeholder($value);
1540        break;
1541
1542      case '!':
1543        // Pass-through.
1544    }
1545  }
1546  return strtr($string, $args);
1547}
1548
1549/**
1550 * Encodes special characters in a plain-text string for display as HTML.
1551 *
1552 * Also validates strings as UTF-8 to prevent cross site scripting attacks on
1553 * Internet Explorer 6.
1554 *
1555 * @param string $text
1556 *   The text to be checked or processed.
1557 *
1558 * @return string
1559 *   An HTML safe version of $text. If $text is not valid UTF-8, an empty string
1560 *   is returned and, on PHP < 5.4, a warning may be issued depending on server
1561 *   configuration (see @link https://bugs.php.net/bug.php?id=47494 @endlink).
1562 *
1563 * @see drupal_validate_utf8()
1564 * @ingroup sanitization
1565 */
1566function check_plain($text) {
1567  return htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
1568}
1569
1570/**
1571 * Checks whether a string is valid UTF-8.
1572 *
1573 * All functions designed to filter input should use drupal_validate_utf8
1574 * to ensure they operate on valid UTF-8 strings to prevent bypass of the
1575 * filter.
1576 *
1577 * When text containing an invalid UTF-8 lead byte (0xC0 - 0xFF) is presented
1578 * as UTF-8 to Internet Explorer 6, the program may misinterpret subsequent
1579 * bytes. When these subsequent bytes are HTML control characters such as
1580 * quotes or angle brackets, parts of the text that were deemed safe by filters
1581 * end up in locations that are potentially unsafe; An onerror attribute that
1582 * is outside of a tag, and thus deemed safe by a filter, can be interpreted
1583 * by the browser as if it were inside the tag.
1584 *
1585 * The function does not return FALSE for strings containing character codes
1586 * above U+10FFFF, even though these are prohibited by RFC 3629.
1587 *
1588 * @param $text
1589 *   The text to check.
1590 *
1591 * @return
1592 *   TRUE if the text is valid UTF-8, FALSE if not.
1593 */
1594function drupal_validate_utf8($text) {
1595  if (strlen($text) == 0) {
1596    return TRUE;
1597  }
1598  // With the PCRE_UTF8 modifier 'u', preg_match() fails silently on strings
1599  // containing invalid UTF-8 byte sequences. It does not reject character
1600  // codes above U+10FFFF (represented by 4 or more octets), though.
1601  return (preg_match('/^./us', $text) == 1);
1602}
1603
1604/**
1605 * Returns the equivalent of Apache's $_SERVER['REQUEST_URI'] variable.
1606 *
1607 * Because $_SERVER['REQUEST_URI'] is only available on Apache, we generate an
1608 * equivalent using other environment variables.
1609 */
1610function request_uri() {
1611  if (isset($_SERVER['REQUEST_URI'])) {
1612    $uri = $_SERVER['REQUEST_URI'];
1613  }
1614  else {
1615    if (isset($_SERVER['argv'])) {
1616      $uri = $_SERVER['SCRIPT_NAME'] . '?' . $_SERVER['argv'][0];
1617    }
1618    elseif (isset($_SERVER['QUERY_STRING'])) {
1619      $uri = $_SERVER['SCRIPT_NAME'] . '?' . $_SERVER['QUERY_STRING'];
1620    }
1621    else {
1622      $uri = $_SERVER['SCRIPT_NAME'];
1623    }
1624  }
1625  // Prevent multiple slashes to avoid cross site requests via the Form API.
1626  $uri = '/' . ltrim($uri, '/');
1627
1628  return $uri;
1629}
1630
1631/**
1632 * Logs an exception.
1633 *
1634 * This is a wrapper function for watchdog() which automatically decodes an
1635 * exception.
1636 *
1637 * @param $type
1638 *   The category to which this message belongs.
1639 * @param $exception
1640 *   The exception that is going to be logged.
1641 * @param $message
1642 *   The message to store in the log. If empty, a text that contains all useful
1643 *   information about the passed-in exception is used.
1644 * @param $variables
1645 *   Array of variables to replace in the message on display. Defaults to the
1646 *   return value of _drupal_decode_exception().
1647 * @param $severity
1648 *   The severity of the message, as per RFC 3164.
1649 * @param $link
1650 *   A link to associate with the message.
1651 *
1652 * @see watchdog()
1653 * @see _drupal_decode_exception()
1654 */
1655function watchdog_exception($type, Exception $exception, $message = NULL, $variables = array(), $severity = WATCHDOG_ERROR, $link = NULL) {
1656
1657   // Use a default value if $message is not set.
1658   if (empty($message)) {
1659     // The exception message is run through check_plain() by _drupal_decode_exception().
1660     $message = '%type: !message in %function (line %line of %file).';
1661   }
1662   // $variables must be an array so that we can add the exception information.
1663   if (!is_array($variables)) {
1664     $variables = array();
1665   }
1666
1667   require_once DRUPAL_ROOT . '/includes/errors.inc';
1668   $variables += _drupal_decode_exception($exception);
1669   watchdog($type, $message, $variables, $severity, $link);
1670}
1671
1672/**
1673 * Logs a system message.
1674 *
1675 * @param $type
1676 *   The category to which this message belongs. Can be any string, but the
1677 *   general practice is to use the name of the module calling watchdog().
1678 * @param $message
1679 *   The message to store in the log. Keep $message translatable
1680 *   by not concatenating dynamic values into it! Variables in the
1681 *   message should be added by using placeholder strings alongside
1682 *   the variables argument to declare the value of the placeholders.
1683 *   See t() for documentation on how $message and $variables interact.
1684 * @param $variables
1685 *   Array of variables to replace in the message on display or
1686 *   NULL if message is already translated or not possible to
1687 *   translate.
1688 * @param $severity
1689 *   The severity of the message; one of the following values as defined in
1690 *   @link http://www.faqs.org/rfcs/rfc3164.html RFC 3164: @endlink
1691 *   - WATCHDOG_EMERGENCY: Emergency, system is unusable.
1692 *   - WATCHDOG_ALERT: Alert, action must be taken immediately.
1693 *   - WATCHDOG_CRITICAL: Critical conditions.
1694 *   - WATCHDOG_ERROR: Error conditions.
1695 *   - WATCHDOG_WARNING: Warning conditions.
1696 *   - WATCHDOG_NOTICE: (default) Normal but significant conditions.
1697 *   - WATCHDOG_INFO: Informational messages.
1698 *   - WATCHDOG_DEBUG: Debug-level messages.
1699 * @param $link
1700 *   A link to associate with the message.
1701 *
1702 * @see watchdog_severity_levels()
1703 * @see hook_watchdog()
1704 */
1705function watchdog($type, $message, $variables = array(), $severity = WATCHDOG_NOTICE, $link = NULL) {
1706  global $user, $base_root;
1707
1708  static $in_error_state = FALSE;
1709
1710  // It is possible that the error handling will itself trigger an error. In that case, we could
1711  // end up in an infinite loop. To avoid that, we implement a simple static semaphore.
1712  if (!$in_error_state && function_exists('module_implements')) {
1713    $in_error_state = TRUE;
1714
1715    // The user object may not exist in all conditions, so 0 is substituted if needed.
1716    $user_uid = isset($user->uid) ? $user->uid : 0;
1717
1718    // Prepare the fields to be logged
1719    $log_entry = array(
1720      'type'        => $type,
1721      'message'     => $message,
1722      'variables'   => $variables,
1723      'severity'    => $severity,
1724      'link'        => $link,
1725      'user'        => $user,
1726      'uid'         => $user_uid,
1727      'request_uri' => $base_root . request_uri(),
1728      'referer'     => isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : ',
1729      'ip'          => ip_address(),
1730      // Request time isn't accurate for long processes, use time() instead.
1731      'timestamp'   => time(),
1732    );
1733
1734    // Call the logging hooks to log/process the message
1735    foreach (module_implements('watchdog') as $module) {
1736      module_invoke($module, 'watchdog', $log_entry);
1737    }
1738
1739    // It is critical that the semaphore is only cleared here, in the parent
1740    // watchdog() call (not outside the loop), to prevent recursive execution.
1741    $in_error_state = FALSE;
1742  }
1743}
1744
1745/**
1746 * Sets a message to display to the user.
1747 *
1748 * Messages are stored in a session variable and displayed in page.tpl.php via
1749 * the $messages theme variable.
1750 *
1751 * Example usage:
1752 * @code
1753 * drupal_set_message(t('An error occurred and processing did not complete.'), 'error');
1754 * @endcode
1755 *
1756 * @param string $message
1757 *   (optional) The translated message to be displayed to the user. For
1758 *   consistency with other messages, it should begin with a capital letter and
1759 *   end with a period.
1760 * @param string $type
1761 *   (optional) The message's type. Defaults to 'status'. These values are
1762 *   supported:
1763 *   - 'status'
1764 *   - 'warning'
1765 *   - 'error'
1766 * @param bool $repeat
1767 *   (optional) If this is FALSE and the message is already set, then the
1768 *   message won't be repeated. Defaults to TRUE.
1769 *
1770 * @return array|null
1771 *   A multidimensional array with keys corresponding to the set message types.
1772 *   The indexed array values of each contain the set messages for that type.
1773 *   Or, if there are no messages set, the function returns NULL.
1774 *
1775 * @see drupal_get_messages()
1776 * @see theme_status_messages()
1777 */
1778function drupal_set_message($message = NULL, $type = 'status', $repeat = TRUE) {
1779  if ($message) {
1780    if (!isset($_SESSION['messages'][$type])) {
1781      $_SESSION['messages'][$type] = array();
1782    }
1783
1784    if ($repeat || !in_array($message, $_SESSION['messages'][$type])) {
1785      $_SESSION['messages'][$type][] = $message;
1786    }
1787
1788    // Mark this page as being uncacheable.
1789    drupal_page_is_cacheable(FALSE);
1790  }
1791
1792  // Messages not set when DB connection fails.
1793  return isset($_SESSION['messages']) ? $_SESSION['messages'] : NULL;
1794}
1795
1796/**
1797 * Returns all messages that have been set with drupal_set_message().
1798 *
1799 * @param string $type
1800 *   (optional) Limit the messages returned by type. Defaults to NULL, meaning
1801 *   all types. These values are supported:
1802 *   - NULL
1803 *   - 'status'
1804 *   - 'warning'
1805 *   - 'error'
1806 * @param bool $clear_queue
1807 *   (optional) If this is TRUE, the queue will be cleared of messages of the
1808 *   type specified in the $type parameter. Otherwise the queue will be left
1809 *   intact. Defaults to TRUE.
1810 *
1811 * @return array
1812 *   A multidimensional array with keys corresponding to the set message types.
1813 *   The indexed array values of each contain the set messages for that type.
1814 *   The messages returned are limited to the type specified in the $type
1815 *   parameter. If there are no messages of the specified type, an empty array
1816 *   is returned.
1817 *
1818 * @see drupal_set_message()
1819 * @see theme_status_messages()
1820 */
1821function drupal_get_messages($type = NULL, $clear_queue = TRUE) {
1822  if ($messages = drupal_set_message()) {
1823    if ($type) {
1824      if ($clear_queue) {
1825        unset($_SESSION['messages'][$type]);
1826      }
1827      if (isset($messages[$type])) {
1828        return array($type => $messages[$type]);
1829      }
1830    }
1831    else {
1832      if ($clear_queue) {
1833        unset($_SESSION['messages']);
1834      }
1835      return $messages;
1836    }
1837  }
1838  return array();
1839}
1840
1841/**
1842 * Gets the title of the current page.
1843 *
1844 * The title is displayed on the page and in the title bar.
1845 *
1846 * @return
1847 *   The current page's title.
1848 */
1849function drupal_get_title() {
1850  $title = drupal_set_title();
1851
1852  // During a bootstrap, menu.inc is not included and thus we cannot provide a title.
1853  if (!isset($title) && function_exists('menu_get_active_title')) {
1854    $title = check_plain(menu_get_active_title());
1855  }
1856
1857  return $title;
1858}
1859
1860/**
1861 * Sets the title of the current page.
1862 *
1863 * The title is displayed on the page and in the title bar.
1864 *
1865 * @param $title
1866 *   Optional string value to assign to the page title; or if set to NULL
1867 *   (default), leaves the current title unchanged.
1868 * @param $output
1869 *   Optional flag - normally should be left as CHECK_PLAIN. Only set to
1870 *   PASS_THROUGH if you have already removed any possibly dangerous code
1871 *   from $title using a function like check_plain() or filter_xss(). With this
1872 *   flag the string will be passed through unchanged.
1873 *
1874 * @return
1875 *   The updated title of the current page.
1876 */
1877function drupal_set_title($title = NULL, $output = CHECK_PLAIN) {
1878  $stored_title = &drupal_static(__FUNCTION__);
1879
1880  if (isset($title)) {
1881    $stored_title = ($output == PASS_THROUGH) ? $title : check_plain($title);
1882  }
1883
1884  return $stored_title;
1885}
1886
1887/**
1888 * Checks to see if an IP address has been blocked.
1889 *
1890 * Blocked IP addresses are stored in the database by default. However for
1891 * performance reasons we allow an override in settings.php. This allows us
1892 * to avoid querying the database at this critical stage of the bootstrap if
1893 * an administrative interface for IP address blocking is not required.
1894 *
1895 * @param $ip
1896 *   IP address to check.
1897 *
1898 * @return bool
1899 *   TRUE if access is denied, FALSE if access is allowed.
1900 */
1901function drupal_is_denied($ip) {
1902  // Because this function is called on every page request, we first check
1903  // for an array of IP addresses in settings.php before querying the
1904  // database.
1905  $blocked_ips = variable_get('blocked_ips');
1906  $denied = FALSE;
1907  if (isset($blocked_ips) && is_array($blocked_ips)) {
1908    $denied = in_array($ip, $blocked_ips);
1909  }
1910  // Only check if database.inc is loaded already. If
1911  // $conf['page_cache_without_database'] = TRUE; is set in settings.php,
1912  // then the database won't be loaded here so the IPs in the database
1913  // won't be denied. However the user asked explicitly not to use the
1914  // database and also in this case it's quite likely that the user relies
1915  // on higher performance solutions like a firewall.
1916  elseif (class_exists('Database', FALSE)) {
1917    $denied = (bool)db_query("SELECT 1 FROM {blocked_ips} WHERE ip = :ip", array(':ip' => $ip))->fetchField();
1918  }
1919  return $denied;
1920}
1921
1922/**
1923 * Handles denied users.
1924 *
1925 * @param $ip
1926 *   IP address to check. Prints a message and exits if access is denied.
1927 */
1928function drupal_block_denied($ip) {
1929  // Deny access to blocked IP addresses - t() is not yet available.
1930  if (drupal_is_denied($ip)) {
1931    header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
1932    print 'Sorry, ' . check_plain(ip_address()) . ' has been banned.';
1933    exit();
1934  }
1935}
1936
1937/**
1938 * Returns a URL-safe, base64 encoded string of highly randomized bytes (over the full 8-bit range).
1939 *
1940 * @param $byte_count
1941 *   The number of random bytes to fetch and base64 encode.
1942 *
1943 * @return string
1944 *   The base64 encoded result will have a length of up to 4 * $byte_count.
1945 */
1946function drupal_random_key($byte_count = 32) {
1947  return drupal_base64_encode(drupal_random_bytes($byte_count));
1948}
1949
1950/**
1951 * Returns a URL-safe, base64 encoded version of the supplied string.
1952 *
1953 * @param $string
1954 *   The string to convert to base64.
1955 *
1956 * @return string
1957 */
1958function drupal_base64_encode($string) {
1959  $data = base64_encode($string);
1960  // Modify the output so it's safe to use in URLs.
1961  return strtr($data, array('+' => '-', '/' => '_', '=' => '));
1962}
1963
1964/**
1965 * Returns a string of highly randomized bytes (over the full 8-bit range).
1966 *
1967 * This function is better than simply calling mt_rand() or any other built-in
1968 * PHP function because it can return a long string of bytes (compared to < 4
1969 * bytes normally from mt_rand()) and uses the best available pseudo-random
1970 * source.
1971 *
1972 * @param $count
1973 *   The number of characters (bytes) to return in the string.
1974 */
1975function drupal_random_bytes($count)  {
1976  // $random_state does not use drupal_static as it stores random bytes.
1977  static $random_state, $bytes, $has_openssl;
1978
1979  $missing_bytes = $count - strlen($bytes);
1980
1981  if ($missing_bytes > 0) {
1982    // PHP versions prior 5.3.4 experienced openssl_random_pseudo_bytes()
1983    // locking on Windows and rendered it unusable.
1984    if (!isset($has_openssl)) {
1985      $has_openssl = version_compare(PHP_VERSION, '5.3.4', '>=') && function_exists('openssl_random_pseudo_bytes');
1986    }
1987
1988    // openssl_random_pseudo_bytes() will find entropy in a system-dependent
1989    // way.
1990    if ($has_openssl) {
1991      $bytes .= openssl_random_pseudo_bytes($missing_bytes);
1992    }
1993
1994    // Else, read directly from /dev/urandom, which is available on many *nix
1995    // systems and is considered cryptographically secure.
1996    elseif ($fh = @fopen('/dev/urandom', 'rb')) {
1997      // PHP only performs buffered reads, so in reality it will always read
1998      // at least 4096 bytes. Thus, it costs nothing extra to read and store
1999      // that much so as to speed any additional invocations.
2000      $bytes .= fread($fh, max(4096, $missing_bytes));
2001      fclose($fh);
2002    }
2003
2004    // If we couldn't get enough entropy, this simple hash-based PRNG will
2005    // generate a good set of pseudo-random bytes on any system.
2006    // Note that it may be important that our $random_state is passed
2007    // through hash() prior to being rolled into $output, that the two hash()
2008    // invocations are different, and that the extra input into the first one -
2009    // the microtime() - is prepended rather than appended. This is to avoid
2010    // directly leaking $random_state via the $output stream, which could
2011    // allow for trivial prediction of further "random" numbers.
2012    if (strlen($bytes) < $count) {
2013      // Initialize on the first call. The contents of $_SERVER includes a mix of
2014      // user-specific and system information that varies a little with each page.
2015      if (!isset($random_state)) {
2016        $random_state = print_r($_SERVER, TRUE);
2017        if (function_exists('getmypid')) {
2018          // Further initialize with the somewhat random PHP process ID.
2019          $random_state .= getmypid();
2020        }
2021        $bytes = ';
2022      }
2023
2024      do {
2025        $random_state = hash('sha256', microtime() . mt_rand() . $random_state);
2026        $bytes .= hash('sha256', mt_rand() . $random_state, TRUE);
2027      }
2028      while (strlen($bytes) < $count);
2029    }
2030  }
2031  $output = substr($bytes, 0, $count);
2032  $bytes = substr($bytes, $count);
2033  return $output;
2034}
2035
2036/**
2037 * Calculates a base-64 encoded, URL-safe sha-256 hmac.
2038 *
2039 * @param string $data
2040 *   String to be validated with the hmac.
2041 * @param string $key
2042 *   A secret string key.
2043 *
2044 * @return string
2045 *   A base-64 encoded sha-256 hmac, with + replaced with -, / with _ and
2046 *   any = padding characters removed.
2047 */
2048function drupal_hmac_base64($data, $key) {
2049  // Casting $data and $key to strings here is necessary to avoid empty string
2050  // results of the hash function if they are not scalar values. As this
2051  // function is used in security-critical contexts like token validation it is
2052  // important that it never returns an empty string.
2053  $hmac = base64_encode(hash_hmac('sha256', (string) $data, (string) $key, TRUE));
2054  // Modify the hmac so it's safe to use in URLs.
2055  return strtr($hmac, array('+' => '-', '/' => '_', '=' => '));
2056}
2057
2058/**
2059 * Calculates a base-64 encoded, URL-safe sha-256 hash.
2060 *
2061 * @param $data
2062 *   String to be hashed.
2063 *
2064 * @return
2065 *   A base-64 encoded sha-256 hash, with + replaced with -, / with _ and
2066 *   any = padding characters removed.
2067 */
2068function drupal_hash_base64($data) {
2069  $hash = base64_encode(hash('sha256', $data, TRUE));
2070  // Modify the hash so it's safe to use in URLs.
2071  return strtr($hash, array('+' => '-', '/' => '_', '=' => '));
2072}
2073
2074/**
2075 * Merges multiple arrays, recursively, and returns the merged array.
2076 *
2077 * This function is similar to PHP's array_merge_recursive() function, but it
2078 * handles non-array values differently. When merging values that are not both
2079 * arrays, the latter value replaces the former rather than merging with it.
2080 *
2081 * Example:
2082 * @code
2083 * $link_options_1 = array('fragment' => 'x', 'attributes' => array('title' => t('X'), 'class' => array('a', 'b')));
2084 * $link_options_2 = array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('c', 'd')));
2085 *
2086 * // This results in array('fragment' => array('x', 'y'), 'attributes' => array('title' => array(t('X'), t('Y')), 'class' => array('a', 'b', 'c', 'd'))).
2087 * $incorrect = array_merge_recursive($link_options_1, $link_options_2);
2088 *
2089 * // This results in array('fragment' => 'y', 'attributes' => array('title' => t('Y'), 'class' => array('a', 'b', 'c', 'd'))).
2090 * $correct = drupal_array_merge_deep($link_options_1, $link_options_2);
2091 * @endcode
2092 *
2093 * @param ...
2094 *   Arrays to merge.
2095 *
2096 * @return
2097 *   The merged array.
2098 *
2099 * @see drupal_array_merge_deep_array()
2100 */
2101function drupal_array_merge_deep() {
2102  $args = func_get_args();
2103  return drupal_array_merge_deep_array($args);
2104}
2105
2106/**
2107 * Merges multiple arrays, recursively, and returns the merged array.
2108 *
2109 * This function is equivalent to drupal_array_merge_deep(), except the
2110 * input arrays are passed as a single array parameter rather than a variable
2111 * parameter list.
2112 *
2113 * The following are equivalent:
2114 * - drupal_array_merge_deep($a, $b);
2115 * - drupal_array_merge_deep_array(array($a, $b));
2116 *
2117 * The following are also equivalent:
2118 * - call_user_func_array('drupal_array_merge_deep', $arrays_to_merge);
2119 * - drupal_array_merge_deep_array($arrays_to_merge);
2120 *
2121 * @see drupal_array_merge_deep()
2122 */
2123function drupal_array_merge_deep_array($arrays) {
2124  $result = array();
2125
2126  foreach ($arrays as $array) {
2127    foreach ($array as $key => $value) {
2128      // Renumber integer keys as array_merge_recursive() does. Note that PHP
2129      // automatically converts array keys that are integer strings (e.g., '1')
2130      // to integers.
2131      if (is_integer($key)) {
2132        $result[] = $value;
2133      }
2134      // Recurse when both values are arrays.
2135      elseif (isset($result[$key]) && is_array($result[$key]) && is_array($value)) {
2136        $result[$key] = drupal_array_merge_deep_array(array($result[$key], $value));
2137      }
2138      // Otherwise, use the latter value, overriding any previous value.
2139      else {
2140        $result[$key] = $value;
2141      }
2142    }
2143  }
2144
2145  return $result;
2146}
2147
2148/**
2149 * Generates a default anonymous $user object.
2150 *
2151 * @return Object - the user object.
2152 */
2153function drupal_anonymous_user() {
2154  $user = variable_get('drupal_anonymous_user_object', new stdClass);
2155  $user->uid = 0;
2156  $user->hostname = ip_address();
2157  $user->roles = array();
2158  $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user';
2159  $user->cache = 0;
2160  return $user;
2161}
2162
2163/**
2164 * Ensures Drupal is bootstrapped to the specified phase.
2165 *
2166 * In order to bootstrap Drupal from another PHP script, you can use this code:
2167 * @code
2168 *   define('DRUPAL_ROOT', '/path/to/drupal');
2169 *   require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
2170 *   drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
2171 * @endcode
2172 *
2173 * @param int $phase
2174 *   A constant telling which phase to bootstrap to. When you bootstrap to a
2175 *   particular phase, all earlier phases are run automatically. Possible
2176 *   values:
2177 *   - DRUPAL_BOOTSTRAP_CONFIGURATION: Initializes configuration.
2178 *   - DRUPAL_BOOTSTRAP_PAGE_CACHE: Tries to serve a cached page.
2179 *   - DRUPAL_BOOTSTRAP_DATABASE: Initializes the database layer.
2180 *   - DRUPAL_BOOTSTRAP_VARIABLES: Initializes the variable system.
2181 *   - DRUPAL_BOOTSTRAP_SESSION: Initializes session handling.
2182 *   - DRUPAL_BOOTSTRAP_PAGE_HEADER: Sets up the page header.
2183 *   - DRUPAL_BOOTSTRAP_LANGUAGE: Finds out the language of the page.
2184 *   - DRUPAL_BOOTSTRAP_FULL: Fully loads Drupal. Validates and fixes input
2185 *     data.
2186 * @param boolean $new_phase
2187 *   A boolean, set to FALSE if calling drupal_bootstrap from inside a
2188 *   function called from drupal_bootstrap (recursion).
2189 *
2190 * @return int
2191 *   The most recently completed phase.
2192 */
2193function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
2194  // Not drupal_static(), because does not depend on any run-time information.
2195  static $phases = array(
2196    DRUPAL_BOOTSTRAP_CONFIGURATION,
2197    DRUPAL_BOOTSTRAP_PAGE_CACHE,
2198    DRUPAL_BOOTSTRAP_DATABASE,
2199    DRUPAL_BOOTSTRAP_VARIABLES,
2200    DRUPAL_BOOTSTRAP_SESSION,
2201    DRUPAL_BOOTSTRAP_PAGE_HEADER,
2202    DRUPAL_BOOTSTRAP_LANGUAGE,
2203    DRUPAL_BOOTSTRAP_FULL,
2204  );
2205  // Not drupal_static(), because the only legitimate API to control this is to
2206  // call drupal_bootstrap() with a new phase parameter.
2207  static $final_phase;
2208  // Not drupal_static(), because it's impossible to roll back to an earlier
2209  // bootstrap state.
2210  static $stored_phase = -1;
2211
2212  if (isset($phase)) {
2213    // When not recursing, store the phase name so it's not forgotten while
2214    // recursing but take care of not going backwards.
2215    if ($new_phase && $phase >= $stored_phase) {
2216      $final_phase = $phase;
2217    }
2218
2219    // Call a phase if it has not been called before and is below the requested
2220    // phase.
2221    while ($phases && $phase > $stored_phase && $final_phase > $stored_phase) {
2222      $current_phase = array_shift($phases);
2223
2224      // This function is re-entrant. Only update the completed phase when the
2225      // current call actually resulted in a progress in the bootstrap process.
2226      if ($current_phase > $stored_phase) {
2227        $stored_phase = $current_phase;
2228      }
2229
2230      switch ($current_phase) {
2231        case DRUPAL_BOOTSTRAP_CONFIGURATION:
2232          _drupal_bootstrap_configuration();
2233          break;
2234
2235        case DRUPAL_BOOTSTRAP_PAGE_CACHE:
2236          _drupal_bootstrap_page_cache();
2237          break;
2238
2239        case DRUPAL_BOOTSTRAP_DATABASE:
2240          _drupal_bootstrap_database();
2241          break;
2242
2243        case DRUPAL_BOOTSTRAP_VARIABLES:
2244          _drupal_bootstrap_variables();
2245          break;
2246
2247        case DRUPAL_BOOTSTRAP_SESSION:
2248          require_once DRUPAL_ROOT . '/' . variable_get('session_inc', 'includes/session.inc');
2249          drupal_session_initialize();
2250          break;
2251
2252        case DRUPAL_BOOTSTRAP_PAGE_HEADER:
2253          _drupal_bootstrap_page_header();
2254          break;
2255
2256        case DRUPAL_BOOTSTRAP_LANGUAGE:
2257          drupal_language_initialize();
2258          break;
2259
2260        case DRUPAL_BOOTSTRAP_FULL:
2261          require_once DRUPAL_ROOT . '/includes/common.inc';
2262          _drupal_bootstrap_full();
2263          break;
2264      }
2265    }
2266  }
2267  return $stored_phase;
2268}
2269
2270/**
2271 * Returns the time zone of the current user.
2272 */
2273function drupal_get_user_timezone() {
2274  global $user;
2275  if (variable_get('configurable_timezones', 1) && $user->uid && $user->timezone) {
2276    return $user->timezone;
2277  }
2278  else {
2279    // Ignore PHP strict notice if time zone has not yet been set in the php.ini
2280    // configuration.
2281    return variable_get('date_default_timezone', @date_default_timezone_get());
2282  }
2283}
2284
2285/**
2286 * Gets a salt useful for hardening against SQL injection.
2287 *
2288 * @return
2289 *   A salt based on information in settings.php, not in the database.
2290 */
2291function drupal_get_hash_salt() {
2292  global $drupal_hash_salt, $databases;
2293  // If the $drupal_hash_salt variable is empty, a hash of the serialized
2294  // database credentials is used as a fallback salt.
2295  return empty($drupal_hash_salt) ? hash('sha256', serialize($databases)) : $drupal_hash_salt;
2296}
2297
2298/**
2299 * Provides custom PHP error handling.
2300 *
2301 * @param $error_level
2302 *   The level of the error raised.
2303 * @param $message
2304 *   The error message.
2305 * @param $filename
2306 *   The filename that the error was raised in.
2307 * @param $line
2308 *   The line number the error was raised at.
2309 * @param $context
2310 *   An array that points to the active symbol table at the point the error
2311 *   occurred.
2312 */
2313function _drupal_error_handler($error_level, $message, $filename, $line, $context) {
2314  require_once DRUPAL_ROOT . '/includes/errors.inc';
2315  _drupal_error_handler_real($error_level, $message, $filename, $line, $context);
2316}
2317
2318/**
2319 * Provides custom PHP exception handling.
2320 *
2321 * Uncaught exceptions are those not enclosed in a try/catch block. They are
2322 * always fatal: the execution of the script will stop as soon as the exception
2323 * handler exits.
2324 *
2325 * @param $exception
2326 *   The exception object that was thrown.
2327 */
2328function _drupal_exception_handler($exception) {
2329  require_once DRUPAL_ROOT . '/includes/errors.inc';
2330
2331  try {
2332    // Log the message to the watchdog and return an error page to the user.
2333    _drupal_log_error(_drupal_decode_exception($exception), TRUE);
2334  }
2335  catch (Exception $exception2) {
2336    // Another uncaught exception was thrown while handling the first one.
2337    // If we are displaying errors, then do so with no possibility of a further uncaught exception being thrown.
2338    if (error_displayable()) {
2339      print '<h1>Additional uncaught exception thrown while handling exception.</h1>';
2340      print '<h2>Original</h2><p>' . _drupal_render_exception_safe($exception) . '</p>';
2341      print '<h2>Additional</h2><p>' . _drupal_render_exception_safe($exception2) . '</p><hr />';
2342    }
2343  }
2344}
2345
2346/**
2347 * Sets up the script environment and loads settings.php.
2348 */
2349function _drupal_bootstrap_configuration() {
2350  // Set the Drupal custom error handler.
2351  set_error_handler('_drupal_error_handler');
2352  set_exception_handler('_drupal_exception_handler');
2353
2354  drupal_environment_initialize();
2355  // Start a page timer:
2356  timer_start('page');
2357  // Initialize the configuration, including variables from settings.php.
2358  drupal_settings_initialize();
2359}
2360
2361/**
2362 * Attempts to serve a page from the cache.
2363 */
2364function _drupal_bootstrap_page_cache() {
2365  global $user;
2366
2367  // Allow specifying special cache handlers in settings.php, like
2368  // using memcached or files for storing cache information.
2369  require_once DRUPAL_ROOT . '/includes/cache.inc';
2370  foreach (variable_get('cache_backends', array()) as $include) {
2371    require_once DRUPAL_ROOT . '/' . $include;
2372  }
2373  // Check for a cache mode force from settings.php.
2374  if (variable_get('page_cache_without_database')) {
2375    $cache_enabled = TRUE;
2376  }
2377  else {
2378    drupal_bootstrap(DRUPAL_BOOTSTRAP_VARIABLES, FALSE);
2379    $cache_enabled = variable_get('cache');
2380  }
2381  drupal_block_denied(ip_address());
2382  // If there is no session cookie and cache is enabled (or forced), try
2383  // to serve a cached page.
2384  if (!isset($_COOKIE[session_name()]) && $cache_enabled) {
2385    // Make sure there is a user object because its timestamp will be
2386    // checked, hook_boot might check for anonymous user etc.
2387    $user = drupal_anonymous_user();
2388    // Get the page from the cache.
2389    $cache = drupal_page_get_cache();
2390    // If there is a cached page, display it.
2391    if (is_object($cache)) {
2392      header('X-Drupal-Cache: HIT');
2393      // Restore the metadata cached with the page.
2394      $_GET['q'] = $cache->data['path'];
2395      drupal_set_title($cache->data['title'], PASS_THROUGH);
2396      date_default_timezone_set(drupal_get_user_timezone());
2397      // If the skipping of the bootstrap hooks is not enforced, call
2398      // hook_boot.
2399      if (variable_get('page_cache_invoke_hooks', TRUE)) {
2400        bootstrap_invoke_all('boot');
2401      }
2402      drupal_serve_page_from_cache($cache);
2403      // If the skipping of the bootstrap hooks is not enforced, call
2404      // hook_exit.
2405      if (variable_get('page_cache_invoke_hooks', TRUE)) {
2406        bootstrap_invoke_all('exit');
2407      }
2408      // We are done.
2409      exit;
2410    }
2411    else {
2412      header('X-Drupal-Cache: MISS');
2413    }
2414  }
2415}
2416
2417/**
2418 * Initializes the database system and registers autoload functions.
2419 */
2420function _drupal_bootstrap_database() {
2421  // Redirect the user to the installation script if Drupal has not been
2422  // installed yet (i.e., if no $databases array has been defined in the
2423  // settings.php file) and we are not already installing.
2424  if (empty($GLOBALS['databases']) && !drupal_installation_attempted()) {
2425    include_once DRUPAL_ROOT . '/includes/install.inc';
2426    install_goto('install.php');
2427  }
2428
2429  // The user agent header is used to pass a database prefix in the request when
2430  // running tests. However, for security reasons, it is imperative that we
2431  // validate we ourselves made the request.
2432  if ($test_prefix = drupal_valid_test_ua()) {
2433    // Set the test run id for use in other parts of Drupal.
2434    $test_info = &$GLOBALS['drupal_test_info'];
2435    $test_info['test_run_id'] = $test_prefix;
2436    $test_info['in_child_site'] = TRUE;
2437
2438    foreach ($GLOBALS['databases']['default'] as &$value) {
2439      // Extract the current default database prefix.
2440      if (!isset($value['prefix'])) {
2441        $current_prefix = ';
2442      }
2443      elseif (is_array($value['prefix'])) {
2444        $current_prefix = $value['prefix']['default'];
2445      }
2446      else {
2447        $current_prefix = $value['prefix'];
2448      }
2449
2450      // Remove the current database prefix and replace it by our own.
2451      $value['prefix'] = array(
2452        'default' => $current_prefix . $test_prefix,
2453      );
2454    }
2455  }
2456
2457  // Initialize the database system. Note that the connection
2458  // won't be initialized until it is actually requested.
2459  require_once DRUPAL_ROOT . '/includes/database/database.inc';
2460
2461  // Register autoload functions so that we can access classes and interfaces.
2462  // The database autoload routine comes first so that we can load the database
2463  // system without hitting the database. That is especially important during
2464  // the install or upgrade process.
2465  spl_autoload_register('drupal_autoload_class');
2466  spl_autoload_register('drupal_autoload_interface');
2467}
2468
2469/**
2470 * Loads system variables and all enabled bootstrap modules.
2471 */
2472function _drupal_bootstrap_variables() {
2473  global $conf;
2474
2475  // Initialize the lock system.
2476  require_once DRUPAL_ROOT . '/' . variable_get('lock_inc', 'includes/lock.inc');
2477  lock_initialize();
2478
2479  // Load variables from the database, but do not overwrite variables set in settings.php.
2480  $conf = variable_initialize(isset($conf) ? $conf : array());
2481  // Load bootstrap modules.
2482  require_once DRUPAL_ROOT . '/includes/module.inc';
2483  module_load_all(TRUE);
2484
2485  // Sanitize the destination parameter (which is often used for redirects) to
2486  // prevent open redirect attacks leading to other domains. Sanitize both
2487  // $_GET['destination'] and $_REQUEST['destination'] to protect code that
2488  // relies on either, but do not sanitize $_POST to avoid interfering with
2489  // unrelated form submissions. The sanitization happens here because
2490  // url_is_external() requires the variable system to be available.
2491  if (isset($_GET['destination']) || isset($_REQUEST['destination'])) {
2492    require_once DRUPAL_ROOT . '/includes/common.inc';
2493    // If the destination is an external URL, remove it.
2494    if (isset($_GET['destination']) && url_is_external($_GET['destination'])) {
2495      unset($_GET['destination']);
2496      unset($_REQUEST['destination']);
2497    }
2498    // If there's still something in $_REQUEST['destination'] that didn't come
2499    // from $_GET, check it too.
2500    if (isset($_REQUEST['destination']) && (!isset($_GET['destination']) || $_REQUEST['destination'] != $_GET['destination']) && url_is_external($_REQUEST['destination'])) {
2501      unset($_REQUEST['destination']);
2502    }
2503  }
2504}
2505
2506/**
2507 * Invokes hook_boot(), initializes locking system, and sends HTTP headers.
2508 */
2509function _drupal_bootstrap_page_header() {
2510  bootstrap_invoke_all('boot');
2511
2512  if (!drupal_is_cli()) {
2513    ob_start();
2514    drupal_page_header();
2515  }
2516}
2517
2518/**
2519 * Returns the current bootstrap phase for this Drupal process.
2520 *
2521 * The current phase is the one most recently completed by drupal_bootstrap().
2522 *
2523 * @see drupal_bootstrap()
2524 */
2525function drupal_get_bootstrap_phase() {
2526  return drupal_bootstrap(NULL, FALSE);
2527}
2528
2529/**
2530 * Returns the test prefix if this is an internal request from SimpleTest.
2531 *
2532 * @return
2533 *   Either the simpletest prefix (the string "simpletest" followed by any
2534 *   number of digits) or FALSE if the user agent does not contain a valid
2535 *   HMAC and timestamp.
2536 */
2537function drupal_valid_test_ua() {
2538  // No reason to reset this.
2539  static $test_prefix;
2540
2541  if (isset($test_prefix)) {
2542    return $test_prefix;
2543  }
2544
2545  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^(simpletest\d+);(.+);(.+);(.+)$/", $_SERVER['HTTP_USER_AGENT'], $matches)) {
2546    list(, $prefix, $time, $salt, $hmac) = $matches;
2547    $check_string =  $prefix . ';' . $time . ';' . $salt;
2548    // We use the salt from settings.php to make the HMAC key, since
2549    // the database is not yet initialized and we can't access any Drupal variables.
2550    // The file properties add more entropy not easily accessible to others.
2551    $key = drupal_get_hash_salt() . filectime(__FILE__) . fileinode(__FILE__);
2552    $time_diff = REQUEST_TIME - $time;
2553    // Since we are making a local request a 5 second time window is allowed,
2554    // and the HMAC must match.
2555    if ($time_diff >= 0 && $time_diff <= 5 && $hmac == drupal_hmac_base64($check_string, $key)) {
2556      $test_prefix = $prefix;
2557      return $test_prefix;
2558    }
2559  }
2560
2561  $test_prefix = FALSE;
2562  return $test_prefix;
2563}
2564
2565/**
2566 * Generates a user agent string with a HMAC and timestamp for simpletest.
2567 */
2568function drupal_generate_test_ua($prefix) {
2569  static $key;
2570
2571  if (!isset($key)) {
2572    // We use the salt from settings.php to make the HMAC key, since
2573    // the database is not yet initialized and we can't access any Drupal variables.
2574    // The file properties add more entropy not easily accessible to others.
2575    $key = drupal_get_hash_salt() . filectime(__FILE__) . fileinode(__FILE__);
2576  }
2577  // Generate a moderately secure HMAC based on the database credentials.
2578  $salt = uniqid(', TRUE);
2579  $check_string = $prefix . ';' . time() . ';' . $salt;
2580  return $check_string . ';' . drupal_hmac_base64($check_string, $key);
2581}
2582
2583/**
2584 * Enables use of the theme system without requiring database access.
2585 *
2586 * Loads and initializes the theme system for site installs, updates and when
2587 * the site is in maintenance mode. This also applies when the database fails.
2588 *
2589 * @see _drupal_maintenance_theme()
2590 */
2591function drupal_maintenance_theme() {
2592  require_once DRUPAL_ROOT . '/includes/theme.maintenance.inc';
2593  _drupal_maintenance_theme();
2594}
2595
2596/**
2597 * Returns a simple 404 Not Found page.
2598 *
2599 * If fast 404 pages are enabled, and this is a matching page then print a
2600 * simple 404 page and exit.
2601 *
2602 * This function is called from drupal_deliver_html_page() at the time when a
2603 * a normal 404 page is generated, but it can also optionally be called directly
2604 * from settings.php to prevent a Drupal bootstrap on these pages. See
2605 * documentation in settings.php for the benefits and drawbacks of using this.
2606 *
2607 * Paths to dynamically-generated content, such as image styles, should also be
2608 * accounted for in this function.
2609 */
2610function drupal_fast_404() {
2611  $exclude_paths = variable_get('404_fast_paths_exclude', FALSE);
2612  if ($exclude_paths && !preg_match($exclude_paths, $_GET['q'])) {
2613    $fast_paths = variable_get('404_fast_paths', FALSE);
2614    if ($fast_paths && preg_match($fast_paths, $_GET['q'])) {
2615      drupal_add_http_header('Status', '404 Not Found');
2616      $fast_404_html = variable_get('404_fast_html', '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>404 Not Found</title></head><body><h1>Not Found</h1><p>The requested URL "@path" was not found on this server.</p></body></html>');
2617      // Replace @path in the variable with the page path.
2618      print strtr($fast_404_html, array('@path' => check_plain(request_uri())));
2619      exit;
2620    }
2621  }
2622}
2623
2624/**
2625 * Returns TRUE if a Drupal installation is currently being attempted.
2626 */
2627function drupal_installation_attempted() {
2628  return defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'install';
2629}
2630
2631/**
2632 * Returns the name of the proper localization function.
2633 *
2634 * get_t() exists to support localization for code that might run during
2635 * the installation phase, when some elements of the system might not have
2636 * loaded.
2637 *
2638 * This would include implementations of hook_install(), which could run
2639 * during the Drupal installation phase, and might also be run during
2640 * non-installation time, such as while installing the module from the
2641 * module administration page.
2642 *
2643 * Example usage:
2644 * @code
2645 *   $t = get_t();
2646 *   $translated = $t('translate this');
2647 * @endcode
2648 *
2649 * Use t() if your code will never run during the Drupal installation phase.
2650 * Use st() if your code will only run during installation and never any other
2651 * time. Use get_t() if your code could run in either circumstance.
2652 *
2653 * @see t()
2654 * @see st()
2655 * @ingroup sanitization
2656 */
2657function get_t() {
2658  static $t;
2659  // This is not converted to drupal_static because there is no point in
2660  // resetting this as it can not change in the course of a request.
2661  if (!isset($t)) {
2662    $t = drupal_installation_attempted() ? 'st' : 't';
2663  }
2664  return $t;
2665}
2666
2667/**
2668 * Initializes all the defined language types.
2669 */
2670function drupal_language_initialize() {
2671  $types = language_types();
2672
2673  // Ensure the language is correctly returned, even without multilanguage
2674  // support. Also make sure we have a $language fallback, in case a language
2675  // negotiation callback needs to do a full bootstrap.
2676  // Useful for eg. XML/HTML 'lang' attributes.
2677  $default = language_default();
2678  foreach ($types as $type) {
2679    $GLOBALS[$type] = $default;
2680  }
2681  if (drupal_multilingual()) {
2682    include_once DRUPAL_ROOT . '/includes/language.inc';
2683    foreach ($types as $type) {
2684      $GLOBALS[$type] = language_initialize($type);
2685    }
2686    // Allow modules to react on language system initialization in multilingual
2687    // environments.
2688    bootstrap_invoke_all('language_init');
2689  }
2690}
2691
2692/**
2693 * Returns a list of the built-in language types.
2694 *
2695 * @return
2696 *   An array of key-values pairs where the key is the language type and the
2697 *   value is its configurability.
2698 */
2699function drupal_language_types() {
2700  return array(
2701    LANGUAGE_TYPE_INTERFACE => TRUE,
2702    LANGUAGE_TYPE_CONTENT => FALSE,
2703    LANGUAGE_TYPE_URL => FALSE,
2704  );
2705}
2706
2707/**
2708 * Returns TRUE if there is more than one language enabled.
2709 *
2710 * @return
2711 *   TRUE if more than one language is enabled.
2712 */
2713function drupal_multilingual() {
2714  // The "language_count" variable stores the number of enabled languages to
2715  // avoid unnecessarily querying the database when building the list of
2716  // enabled languages on monolingual sites.
2717  return variable_get('language_count', 1) > 1;
2718}
2719
2720/**
2721 * Returns an array of the available language types.
2722 *
2723 * @return
2724 *   An array of all language types where the keys of each are the language type
2725 *   name and its value is its configurability (TRUE/FALSE).
2726 */
2727function language_types() {
2728  return array_keys(variable_get('language_types', drupal_language_types()));
2729}
2730
2731/**
2732 * Returns a list of installed languages, indexed by the specified key.
2733 *
2734 * @param $field
2735 *   (optional) The field to index the list with.
2736 *
2737 * @return
2738 *   An associative array, keyed on the values of $field.
2739 *   - If $field is 'weight' or 'enabled', the array is nested, with the outer
2740 *     array's values each being associative arrays with language codes as
2741 *     keys and language objects as values.
2742 *   - For all other values of $field, the array is only one level deep, and
2743 *     the array's values are language objects.
2744 */
2745function language_list($field = 'language') {
2746  $languages = &drupal_static(__FUNCTION__);
2747  // Init language list
2748  if (!isset($languages)) {
2749    if (drupal_multilingual() || module_exists('locale')) {
2750      $languages['language'] = db_query('SELECT * FROM {languages} ORDER BY weight ASC, name ASC')->fetchAllAssoc('language');
2751      // Users cannot uninstall the native English language. However, we allow
2752      // it to be hidden from the installed languages. Therefore, at least one
2753      // other language must be enabled then.
2754      if (!$languages['language']['en']->enabled && !variable_get('language_native_enabled', TRUE)) {
2755        unset($languages['language']['en']);
2756      }
2757    }
2758    else {
2759      // No locale module, so use the default language only.
2760      $default = language_default();
2761      $languages['language'][$default->language] = $default;
2762    }
2763  }
2764
2765  // Return the array indexed by the right field
2766  if (!isset($languages[$field])) {
2767    $languages[$field] = array();
2768    foreach ($languages['language'] as $lang) {
2769      // Some values should be collected into an array
2770      if (in_array($field, array('enabled', 'weight'))) {
2771        $languages[$field][$lang->$field][$lang->language] = $lang;
2772      }
2773      else {
2774        $languages[$field][$lang->$field] = $lang;
2775      }
2776    }
2777  }
2778  return $languages[$field];
2779}
2780
2781/**
2782 * Returns the default language used on the site
2783 *
2784 * @param $property
2785 *   Optional property of the language object to return
2786 */
2787function language_default($property = NULL) {
2788  $language = variable_get('language_default', (object) array('language' => 'en', 'name' => 'English', 'native' => 'English', 'direction' => 0, 'enabled' => 1, 'plurals' => 0, 'formula' => ', 'domain' => ', 'prefix' => ', 'weight' => 0, 'javascript' => '));
2789  return $property ? $language->$property : $language;
2790}
2791
2792/**
2793 * Returns the requested URL path of the page being viewed.
2794 *
2795 * Examples:
2796 * - http://example.com/node/306 returns "node/306".
2797 * - http://example.com/drupalfolder/node/306 returns "node/306" while
2798 *   base_path() returns "/drupalfolder/".
2799 * - http://example.com/path/alias (which is a path alias for node/306) returns
2800 *   "path/alias" as opposed to the internal path.
2801 * - http://example.com/index.php returns an empty string (meaning: front page).
2802 * - http://example.com/index.php?page=1 returns an empty string.
2803 *
2804 * @return
2805 *   The requested Drupal URL path.
2806 *
2807 * @see current_path()
2808 */
2809function request_path() {
2810  static $path;
2811
2812  if (isset($path)) {
2813    return $path;
2814  }
2815
2816  if (isset($_GET['q']) && is_string($_GET['q'])) {
2817    // This is a request with a ?q=foo/bar query string. $_GET['q'] is
2818    // overwritten in drupal_path_initialize(), but request_path() is called
2819    // very early in the bootstrap process, so the original value is saved in
2820    // $path and returned in later calls.
2821    $path = $_GET['q'];
2822  }
2823  elseif (isset($_SERVER['REQUEST_URI'])) {
2824    // This request is either a clean URL, or 'index.php', or nonsense.
2825    // Extract the path from REQUEST_URI.
2826    $request_path = strtok($_SERVER['REQUEST_URI'], '?');
2827    $base_path_len = strlen(rtrim(dirname($_SERVER['SCRIPT_NAME']), '\/'));
2828    // Unescape and strip $base_path prefix, leaving q without a leading slash.
2829    $path = substr(urldecode($request_path), $base_path_len + 1);
2830    // If the path equals the script filename, either because 'index.php' was
2831    // explicitly provided in the URL, or because the server added it to
2832    // $_SERVER['REQUEST_URI'] even when it wasn't provided in the URL (some
2833    // versions of Microsoft IIS do this), the front page should be served.
2834    if ($path == basename($_SERVER['PHP_SELF'])) {
2835      $path = ';
2836    }
2837  }
2838  else {
2839    // This is the front page.
2840    $path = ';
2841  }
2842
2843  // Under certain conditions Apache's RewriteRule directive prepends the value
2844  // assigned to $_GET['q'] with a slash. Moreover we can always have a trailing
2845  // slash in place, hence we need to normalize $_GET['q'].
2846  $path = trim($path, '/');
2847
2848  return $path;
2849}
2850
2851/**
2852 * Returns a component of the current Drupal path.
2853 *
2854 * When viewing a page at the path "admin/structure/types", for example, arg(0)
2855 * returns "admin", arg(1) returns "structure", and arg(2) returns "types".
2856 *
2857 * Avoid use of this function where possible, as resulting code is hard to
2858 * read. In menu callback functions, attempt to use named arguments. See the
2859 * explanation in menu.inc for how to construct callbacks that take arguments.
2860 * When attempting to use this function to load an element from the current
2861 * path, e.g. loading the node on a node page, use menu_get_object() instead.
2862 *
2863 * @param $index
2864 *   The index of the component, where each component is separated by a '/'
2865 *   (forward-slash), and where the first component has an index of 0 (zero).
2866 * @param $path
2867 *   A path to break into components. Defaults to the path of the current page.
2868 *
2869 * @return
2870 *   The component specified by $index, or NULL if the specified component was
2871 *   not found. If called without arguments, it returns an array containing all
2872 *   the components of the current path.
2873 */
2874function arg($index = NULL, $path = NULL) {
2875  // Even though $arguments doesn't need to be resettable for any functional
2876  // reasons (the result of explode() does not depend on any run-time
2877  // information), it should be resettable anyway in case a module needs to
2878  // free up the memory used by it.
2879  // Use the advanced drupal_static() pattern, since this is called very often.
2880  static $drupal_static_fast;
2881  if (!isset($drupal_static_fast)) {
2882    $drupal_static_fast['arguments'] = &drupal_static(__FUNCTION__);
2883  }
2884  $arguments = &$drupal_static_fast['arguments'];
2885
2886  if (!isset($path)) {
2887    $path = $_GET['q'];
2888  }
2889  if (!isset($arguments[$path])) {
2890    $arguments[$path] = explode('/', $path);
2891  }
2892  if (!isset($index)) {
2893    return $arguments[$path];
2894  }
2895  if (isset($arguments[$path][$index])) {
2896    return $arguments[$path][$index];
2897  }
2898}
2899
2900/**
2901 * Returns the IP address of the client machine.
2902 *
2903 * If Drupal is behind a reverse proxy, we use the X-Forwarded-For header
2904 * instead of $_SERVER['REMOTE_ADDR'], which would be the IP address of
2905 * the proxy server, and not the client's. The actual header name can be
2906 * configured by the reverse_proxy_header variable.
2907 *
2908 * @return
2909 *   IP address of client machine, adjusted for reverse proxy and/or cluster
2910 *   environments.
2911 */
2912function ip_address() {
2913  $ip_address = &drupal_static(__FUNCTION__);
2914
2915  if (!isset($ip_address)) {
2916    $ip_address = $_SERVER['REMOTE_ADDR'];
2917
2918    if (variable_get('reverse_proxy', 0)) {
2919      $reverse_proxy_header = variable_get('reverse_proxy_header', 'HTTP_X_FORWARDED_FOR');
2920      if (!empty($_SERVER[$reverse_proxy_header])) {
2921        // If an array of known reverse proxy IPs is provided, then trust
2922        // the XFF header if request really comes from one of them.
2923        $reverse_proxy_addresses = variable_get('reverse_proxy_addresses', array());
2924
2925        // Turn XFF header into an array.
2926        $forwarded = explode(',', $_SERVER[$reverse_proxy_header]);
2927
2928        // Trim the forwarded IPs; they may have been delimited by commas and spaces.
2929        $forwarded = array_map('trim', $forwarded);
2930
2931        // Tack direct client IP onto end of forwarded array.
2932        $forwarded[] = $ip_address;
2933
2934        // Eliminate all trusted IPs.
2935        $untrusted = array_diff($forwarded, $reverse_proxy_addresses);
2936
2937        // The right-most IP is the most specific we can trust.
2938        $ip_address = array_pop($untrusted);
2939      }
2940    }
2941  }
2942
2943  return $ip_address;
2944}
2945
2946/**
2947 * @addtogroup schemaapi
2948 * @{
2949 */
2950
2951/**
2952 * Gets the schema definition of a table, or the whole database schema.
2953 *
2954 * The returned schema will include any modifications made by any
2955 * module that implements hook_schema_alter().
2956 *
2957 * @param $table
2958 *   The name of the table. If not given, the schema of all tables is returned.
2959 * @param $rebuild
2960 *   If true, the schema will be rebuilt instead of retrieved from the cache.
2961 */
2962function drupal_get_schema($table = NULL, $rebuild = FALSE) {
2963  static $schema;
2964
2965  if ($rebuild || !isset($table)) {
2966    $schema = drupal_get_complete_schema($rebuild);
2967  }
2968  elseif (!isset($schema)) {
2969    $schema = new SchemaCache();
2970  }
2971
2972  if (!isset($table)) {
2973    return $schema;
2974  }
2975  if (isset($schema[$table])) {
2976    return $schema[$table];
2977  }
2978  else {
2979    return FALSE;
2980  }
2981}
2982
2983/**
2984 * Extends DrupalCacheArray to allow for dynamic building of the schema cache.
2985 */
2986class SchemaCache extends DrupalCacheArray {
2987
2988  /**
2989   * Constructs a SchemaCache object.
2990   */
2991  public function __construct() {
2992    // Cache by request method.
2993    parent::__construct('schema:runtime:' . ($_SERVER['REQUEST_METHOD'] == 'GET'), 'cache');
2994  }
2995
2996  /**
2997   * Overrides DrupalCacheArray::resolveCacheMiss().
2998   */
2999  protected function resolveCacheMiss($offset) {
3000    $complete_schema = drupal_get_complete_schema();
3001    $value = isset($complete_schema[$offset]) ? $complete_schema[$offset] :  NULL;
3002    $this->storage[$offset] = $value;
3003    $this->persist($offset);
3004    return $value;
3005  }
3006}
3007
3008/**
3009 * Gets the whole database schema.
3010 *
3011 * The returned schema will include any modifications made by any
3012 * module that implements hook_schema_alter().
3013 *
3014 * @param $rebuild
3015 *   If true, the schema will be rebuilt instead of retrieved from the cache.
3016 */
3017function drupal_get_complete_schema($rebuild = FALSE) {
3018  static $schema = array();
3019
3020  if (empty($schema) || $rebuild) {
3021    // Try to load the schema from cache.
3022    if (!$rebuild && $cached = cache_get('schema')) {
3023      $schema = $cached->data;
3024    }
3025    // Otherwise, rebuild the schema cache.
3026    else {
3027      $schema = array();
3028      // Load the .install files to get hook_schema.
3029      // On some databases this function may be called before bootstrap has
3030      // been completed, so we force the functions we need to load just in case.
3031      if (function_exists('module_load_all_includes')) {
3032        // This function can be called very early in the bootstrap process, so
3033        // we force the module_list() cache to be refreshed to ensure that it
3034        // contains the complete list of modules before we go on to call
3035        // module_load_all_includes().
3036        module_list(TRUE);
3037        module_load_all_includes('install');
3038      }
3039
3040      require_once DRUPAL_ROOT . '/includes/common.inc';
3041      // Invoke hook_schema for all modules.
3042      foreach (module_implements('schema') as $module) {
3043        // Cast the result of hook_schema() to an array, as a NULL return value
3044        // would cause array_merge() to set the $schema variable to NULL as well.
3045        // That would break modules which use $schema further down the line.
3046        $current = (array) module_invoke($module, 'schema');
3047        // Set 'module' and 'name' keys for each table, and remove descriptions,
3048        // as they needlessly slow down cache_get() for every single request.
3049        _drupal_schema_initialize($current, $module);
3050        $schema = array_merge($schema, $current);
3051      }
3052
3053      drupal_alter('schema', $schema);
3054      // If the schema is empty, avoid saving it: some database engines require
3055      // the schema to perform queries, and this could lead to infinite loops.
3056      if (!empty($schema) && (drupal_get_bootstrap_phase() == DRUPAL_BOOTSTRAP_FULL)) {
3057        cache_set('schema', $schema);
3058      }
3059      if ($rebuild) {
3060        cache_clear_all('schema:', 'cache', TRUE);
3061      }
3062    }
3063  }
3064
3065  return $schema;
3066}
3067
3068/**
3069 * @} End of "addtogroup schemaapi".
3070 */
3071
3072
3073/**
3074 * @addtogroup registry
3075 * @{
3076 */
3077
3078/**
3079 * Confirms that an interface is available.
3080 *
3081 * This function is rarely called directly. Instead, it is registered as an
3082 * spl_autoload()  handler, and PHP calls it for us when necessary.
3083 *
3084 * @param $interface
3085 *   The name of the interface to check or load.
3086 *
3087 * @return
3088 *   TRUE if the interface is currently available, FALSE otherwise.
3089 */
3090function drupal_autoload_interface($interface) {
3091  return _registry_check_code('interface', $interface);
3092}
3093
3094/**
3095 * Confirms that a class is available.
3096 *
3097 * This function is rarely called directly. Instead, it is registered as an
3098 * spl_autoload()  handler, and PHP calls it for us when necessary.
3099 *
3100 * @param $class
3101 *   The name of the class to check or load.
3102 *
3103 * @return
3104 *   TRUE if the class is currently available, FALSE otherwise.
3105 */
3106function drupal_autoload_class($class) {
3107  return _registry_check_code('class', $class);
3108}
3109
3110/**
3111 * Checks for a resource in the registry.
3112 *
3113 * @param $type
3114 *   The type of resource we are looking up, or one of the constants
3115 *   REGISTRY_RESET_LOOKUP_CACHE or REGISTRY_WRITE_LOOKUP_CACHE, which
3116 *   signal that we should reset or write the cache, respectively.
3117 * @param $name
3118 *   The name of the resource, or NULL if either of the REGISTRY_* constants
3119 *   is passed in.
3120 *
3121 * @return
3122 *   TRUE if the resource was found, FALSE if not.
3123 *   NULL if either of the REGISTRY_* constants is passed in as $type.
3124 */
3125function _registry_check_code($type, $name = NULL) {
3126  static $lookup_cache, $cache_update_needed;
3127
3128  if ($type == 'class' && class_exists($name) || $type == 'interface' && interface_exists($name)) {
3129    return TRUE;
3130  }
3131
3132  if (!isset($lookup_cache)) {
3133    $lookup_cache = array();
3134    if ($cache = cache_get('lookup_cache', 'cache_bootstrap')) {
3135      $lookup_cache = $cache->data;
3136    }
3137  }
3138
3139  // When we rebuild the registry, we need to reset this cache so
3140  // we don't keep lookups for resources that changed during the rebuild.
3141  if ($type == REGISTRY_RESET_LOOKUP_CACHE) {
3142    $cache_update_needed = TRUE;
3143    $lookup_cache = NULL;
3144    return;
3145  }
3146
3147  // Called from drupal_page_footer, we write to permanent storage if there
3148  // changes to the lookup cache for this request.
3149  if ($type == REGISTRY_WRITE_LOOKUP_CACHE) {
3150    if ($cache_update_needed) {
3151      cache_set('lookup_cache', $lookup_cache, 'cache_bootstrap');
3152    }
3153    return;
3154  }
3155
3156  // $type is either 'interface' or 'class', so we only need the first letter to
3157  // keep the cache key unique.
3158  $cache_key = $type[0] . $name;
3159  if (isset($lookup_cache[$cache_key])) {
3160    if ($lookup_cache[$cache_key]) {
3161      require_once DRUPAL_ROOT . '/' . $lookup_cache[$cache_key];
3162    }
3163    return (bool) $lookup_cache[$cache_key];
3164  }
3165
3166  // This function may get called when the default database is not active, but
3167  // there is no reason we'd ever want to not use the default database for
3168  // this query.
3169  $file = Database::getConnection('default', 'default')
3170    ->select('registry', 'r', array('target' => 'default'))
3171    ->fields('r', array('filename'))
3172    // Use LIKE here to make the query case-insensitive.
3173    ->condition('r.name', db_like($name), 'LIKE')
3174    ->condition('r.type', $type)
3175    ->execute()
3176    ->fetchField();
3177
3178  // Flag that we've run a lookup query and need to update the cache.
3179  $cache_update_needed = TRUE;
3180
3181  // Misses are valuable information worth caching, so cache even if
3182  // $file is FALSE.
3183  $lookup_cache[$cache_key] = $file;
3184
3185  if ($file) {
3186    require_once DRUPAL_ROOT . '/' . $file;
3187    return TRUE;
3188  }
3189  else {
3190    return FALSE;
3191  }
3192}
3193
3194/**
3195 * Rescans all enabled modules and rebuilds the registry.
3196 *
3197 * Rescans all code in modules or includes directories, storing the location of
3198 * each interface or class in the database.
3199 */
3200function registry_rebuild() {
3201  system_rebuild_module_data();
3202  registry_update();
3203}
3204
3205/**
3206 * Updates the registry based on the latest files listed in the database.
3207 *
3208 * This function should be used when system_rebuild_module_data() does not need
3209 * to be called, because it is already known that the list of files in the
3210 * {system} table matches those in the file system.
3211 *
3212 * @return
3213 *   TRUE if the registry was rebuilt, FALSE if another thread was rebuilding
3214 *   in parallel and the current thread just waited for completion.
3215 *
3216 * @see registry_rebuild()
3217 */
3218function registry_update() {
3219  // install_system_module() calls module_enable() which calls into this
3220  // function during initial system installation, so the lock system is neither
3221  // loaded nor does its storage exist yet.
3222  $in_installer = drupal_installation_attempted();
3223  if (!$in_installer && !lock_acquire(__FUNCTION__)) {
3224    // Another request got the lock, wait for it to finish.
3225    lock_wait(__FUNCTION__);
3226    return FALSE;
3227  }
3228
3229  require_once DRUPAL_ROOT . '/includes/registry.inc';
3230  _registry_update();
3231
3232  if (!$in_installer) {
3233    lock_release(__FUNCTION__);
3234  }
3235  return TRUE;
3236}
3237
3238/**
3239 * @} End of "addtogroup registry".
3240 */
3241
3242/**
3243 * Provides central static variable storage.
3244 *
3245 * All functions requiring a static variable to persist or cache data within
3246 * a single page request are encouraged to use this function unless it is
3247 * absolutely certain that the static variable will not need to be reset during
3248 * the page request. By centralizing static variable storage through this
3249 * function, other functions can rely on a consistent API for resetting any
3250 * other function's static variables.
3251 *
3252 * Example:
3253 * @code
3254 * function language_list($field = 'language') {
3255 *   $languages = &drupal_static(__FUNCTION__);
3256 *   if (!isset($languages)) {
3257 *     // If this function is being called for the first time after a reset,
3258 *     // query the database and execute any other code needed to retrieve
3259 *     // information about the supported languages.
3260 *     ...
3261 *   }
3262 *   if (!isset($languages[$field])) {
3263 *     // If this function is being called for the first time for a particular
3264 *     // index field, then execute code needed to index the information already
3265 *     // available in $languages by the desired field.
3266 *     ...
3267 *   }
3268 *   // Subsequent invocations of this function for a particular index field
3269 *   // skip the above two code blocks and quickly return the already indexed
3270 *   // information.
3271 *   return $languages[$field];
3272 * }
3273 * function locale_translate_overview_screen() {
3274 *   // When building the content for the translations overview page, make
3275 *   // sure to get completely fresh information about the supported languages.
3276 *   drupal_static_reset('language_list');
3277 *   ...
3278 * }
3279 * @endcode
3280 *
3281 * In a few cases, a function can have certainty that there is no legitimate
3282 * use-case for resetting that function's static variable. This is rare,
3283 * because when writing a function, it's hard to forecast all the situations in
3284 * which it will be used. A guideline is that if a function's static variable
3285 * does not depend on any information outside of the function that might change
3286 * during a single page request, then it's ok to use the "static" keyword
3287 * instead of the drupal_static() function.
3288 *
3289 * Example:
3290 * @code
3291 * function actions_do(...) {
3292 *   // $stack tracks the number of recursive calls.
3293 *   static $stack;
3294 *   $stack++;
3295 *   if ($stack > variable_get('actions_max_stack', 35)) {
3296 *     ...
3297 *     return;
3298 *   }
3299 *   ...
3300 *   $stack--;
3301 * }
3302 * @endcode
3303 *
3304 * In a few cases, a function needs a resettable static variable, but the
3305 * function is called many times (100+) during a single page request, so
3306 * every microsecond of execution time that can be removed from the function
3307 * counts. These functions can use a more cumbersome, but faster variant of
3308 * calling drupal_static(). It works by storing the reference returned by
3309 * drupal_static() in the calling function's own static variable, thereby
3310 * removing the need to call drupal_static() for each iteration of the function.
3311 * Conceptually, it replaces:
3312 * @code
3313 * $foo = &drupal_static(__FUNCTION__);
3314 * @endcode
3315 * with:
3316 * @code
3317 * // Unfortunately, this does not work.
3318 * static $foo = &drupal_static(__FUNCTION__);
3319 * @endcode
3320 * However, the above line of code does not work, because PHP only allows static
3321 * variables to be initializied by literal values, and does not allow static
3322 * variables to be assigned to references.
3323 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.static
3324 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.references
3325 * The example below shows the syntax needed to work around both limitations.
3326 * For benchmarks and more information, see http://drupal.org/node/619666.
3327 *
3328 * Example:
3329 * @code
3330 * function user_access($string, $account = NULL) {
3331 *   // Use the advanced drupal_static() pattern, since this is called very often.
3332 *   static $drupal_static_fast;
3333 *   if (!isset($drupal_static_fast)) {
3334 *     $drupal_static_fast['perm'] = &drupal_static(__FUNCTION__);
3335 *   }
3336 *   $perm = &$drupal_static_fast['perm'];
3337 *   ...
3338 * }
3339 * @endcode
3340 *
3341 * @param $name
3342 *   Globally unique name for the variable. For a function with only one static,
3343 *   variable, the function name (e.g. via the PHP magic __FUNCTION__ constant)
3344 *   is recommended. For a function with multiple static variables add a
3345 *   distinguishing suffix to the function name for each one.
3346 * @param $default_value
3347 *   Optional default value.
3348 * @param $reset
3349 *   TRUE to reset one or all variables(s). This parameter is only used
3350 *   internally and should not be passed in; use drupal_static_reset() instead.
3351 *   (This function's return value should not be used when TRUE is passed in.)
3352 *
3353 * @return
3354 *   Returns a variable by reference.
3355 *
3356 * @see drupal_static_reset()
3357 */
3358function &drupal_static($name, $default_value = NULL, $reset = FALSE) {
3359  static $data = array(), $default = array();
3360  // First check if dealing with a previously defined static variable.
3361  if (isset($data[$name]) || array_key_exists($name, $data)) {
3362    // Non-NULL $name and both $data[$name] and $default[$name] statics exist.
3363    if ($reset) {
3364      // Reset pre-existing static variable to its default value.
3365      $data[$name] = $default[$name];
3366    }
3367    return $data[$name];
3368  }
3369  // Neither $data[$name] nor $default[$name] static variables exist.
3370  if (isset($name)) {
3371    if ($reset) {
3372      // Reset was called before a default is set and yet a variable must be
3373      // returned.
3374      return $data;
3375    }
3376    // First call with new non-NULL $name. Initialize a new static variable.
3377    $default[$name] = $data[$name] = $default_value;
3378    return $data[$name];
3379  }
3380  // Reset all: ($name == NULL). This needs to be done one at a time so that
3381  // references returned by earlier invocations of drupal_static() also get
3382  // reset.
3383  foreach ($default as $name => $value) {
3384    $data[$name] = $value;
3385  }
3386  // As the function returns a reference, the return should always be a
3387  // variable.
3388  return $data;
3389}
3390
3391/**
3392 * Resets one or all centrally stored static variable(s).
3393 *
3394 * @param $name
3395 *   Name of the static variable to reset. Omit to reset all variables.
3396 *   Resetting all variables should only be used, for example, for running unit
3397 *   tests with a clean environment.
3398 */
3399function drupal_static_reset($name = NULL) {
3400  drupal_static($name, NULL, TRUE);
3401}
3402
3403/**
3404 * Detects whether the current script is running in a command-line environment.
3405 */
3406function drupal_is_cli() {
3407  return (!isset($_SERVER['SERVER_SOFTWARE']) && (php_sapi_name() == 'cli' || (is_numeric($_SERVER['argc']) && $_SERVER['argc'] > 0)));
3408}
3409
3410/**
3411 * Formats text for emphasized display in a placeholder inside a sentence.
3412 *
3413 * Used automatically by format_string().
3414 *
3415 * @param $text
3416 *   The text to format (plain-text).
3417 *
3418 * @return
3419 *   The formatted text (html).
3420 */
3421function drupal_placeholder($text) {
3422  return '<em class="placeholder">' . check_plain($text) . '</em>';
3423}
3424
3425/**
3426 * Registers a function for execution on shutdown.
3427 *
3428 * Wrapper for register_shutdown_function() that catches thrown exceptions to
3429 * avoid "Exception thrown without a stack frame in Unknown".
3430 *
3431 * @param $callback
3432 *   The shutdown function to register.
3433 * @param ...
3434 *   Additional arguments to pass to the shutdown function.
3435 *
3436 * @return
3437 *   Array of shutdown functions to be executed.
3438 *
3439 * @see register_shutdown_function()
3440 * @ingroup php_wrappers
3441 */
3442function &drupal_register_shutdown_function($callback = NULL) {
3443  // We cannot use drupal_static() here because the static cache is reset during
3444  // batch processing, which breaks batch handling.
3445  static $callbacks = array();
3446
3447  if (isset($callback)) {
3448    // Only register the internal shutdown function once.
3449    if (empty($callbacks)) {
3450      register_shutdown_function('_drupal_shutdown_function');
3451    }
3452    $args = func_get_args();
3453    array_shift($args);
3454    // Save callback and arguments
3455    $callbacks[] = array('callback' => $callback, 'arguments' => $args);
3456  }
3457  return $callbacks;
3458}
3459
3460/**
3461 * Executes registered shutdown functions.
3462 */
3463function _drupal_shutdown_function() {
3464  $callbacks = &drupal_register_shutdown_function();
3465
3466  // Set the CWD to DRUPAL_ROOT as it is not guaranteed to be the same as it
3467  // was in the normal context of execution.
3468  chdir(DRUPAL_ROOT);
3469
3470  try {
3471    while (list($key, $callback) = each($callbacks)) {
3472      call_user_func_array($callback['callback'], $callback['arguments']);
3473    }
3474  }
3475  catch (Exception $exception) {
3476    // If we are displaying errors, then do so with no possibility of a further uncaught exception being thrown.
3477   require_once DRUPAL_ROOT . '/includes/errors.inc';
3478   if (error_displayable()) {
3479      print '<h1>Uncaught exception thrown in shutdown function.</h1>';
3480      print '<p>' . _drupal_render_exception_safe($exception) . '</p><hr />';
3481    }
3482  }
3483}
3484
3485/**
3486 * Compares the memory required for an operation to the available memory.
3487 *
3488 * @param $required
3489 *   The memory required for the operation, expressed as a number of bytes with
3490 *   optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G, 6GiB, 8bytes,
3491 *   9mbytes).
3492 * @param $memory_limit
3493 *   (optional) The memory limit for the operation, expressed as a number of
3494 *   bytes with optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G,
3495 *   6GiB, 8bytes, 9mbytes). If no value is passed, the current PHP
3496 *   memory_limit will be used. Defaults to NULL.
3497 *
3498 * @return
3499 *   TRUE if there is sufficient memory to allow the operation, or FALSE
3500 *   otherwise.
3501 */
3502function drupal_check_memory_limit($required, $memory_limit = NULL) {
3503  if (!isset($memory_limit)) {
3504    $memory_limit = ini_get('memory_limit');
3505  }
3506
3507  // There is sufficient memory if:
3508  // - No memory limit is set.
3509  // - The memory limit is set to unlimited (-1).
3510  // - The memory limit is greater than the memory required for the operation.
3511  return ((!$memory_limit) || ($memory_limit == -1) || (parse_size($memory_limit) >= parse_size($required)));
3512}
3513
3514/**
3515 * Invalidates a PHP file from any active opcode caches.
3516 *
3517 * If the opcode cache does not support the invalidation of individual files,
3518 * the entire cache will be flushed.
3519 *
3520 * @param string $filepath
3521 *   The absolute path of the PHP file to invalidate.
3522 */
3523function drupal_clear_opcode_cache($filepath) {
3524  if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 50300) {
3525    // Below PHP 5.3, clearstatcache does not accept any function parameters.
3526    clearstatcache();
3527  }
3528  else {
3529    clearstatcache(TRUE, $filepath);
3530  }
3531
3532  // Zend OPcache.
3533  if (function_exists('opcache_invalidate')) {
3534    opcache_invalidate($filepath, TRUE);
3535  }
3536  // APC.
3537  if (function_exists('apc_delete_file')) {
3538    // apc_delete_file() throws a PHP warning in case the specified file was
3539    // not compiled yet.
3540    // @see http://php.net/apc-delete-file
3541    @apc_delete_file($filepath);
3542  }
3543}