corpus_parole: comparison cms/drupal/includes/file.inc

equal deleted inserted replaced

-:07239de796bb
+:e756a8c72c3d
+<?php
+/**
+* @file
+* API for handling file uploads and server file management.
+*/
+/**
+* Manually include stream wrapper code.
+*
+* Stream wrapper code is included here because there are cases where
+* File API is needed before a bootstrap, or in an alternate order (e.g.
+* maintenance theme).
+*/
+require_once DRUPAL_ROOT . '/includes/stream_wrappers.inc';
+/**
+* @defgroup file File interface
+* @{
+* Common file handling functions.
+*
+* Fields on the file object:
+* - fid: File ID
+* - uid: The {users}.uid of the user who is associated with the file.
+* - filename: Name of the file with no path components. This may differ from
+*   the basename of the filepath if the file is renamed to avoid overwriting
+*   an existing file.
+* - uri: URI of the file.
+* - filemime: The file's MIME type.
+* - filesize: The size of the file in bytes.
+* - status: A bitmapped field indicating the status of the file. The first 8
+*   bits are reserved for Drupal core. The least significant bit indicates
+*   temporary (0) or permanent (1). Temporary files older than
+*   DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during cron runs.
+* - timestamp: UNIX timestamp for the date the file was added to the database.
+*/
+/**
+* Flag used by file_prepare_directory() -- create directory if not present.
+*/
+define('FILE_CREATE_DIRECTORY', 1);
+/**
+* Flag used by file_prepare_directory() -- file permissions may be changed.
+*/
+define('FILE_MODIFY_PERMISSIONS', 2);
+/**
+* Flag for dealing with existing files: Appends number until name is unique.
+*/
+define('FILE_EXISTS_RENAME', 0);
+/**
+* Flag for dealing with existing files: Replace the existing file.
+*/
+define('FILE_EXISTS_REPLACE', 1);
+/**
+* Flag for dealing with existing files: Do nothing and return FALSE.
+*/
+define('FILE_EXISTS_ERROR', 2);
+/**
+* Indicates that the file is permanent and should not be deleted.
+*
+* Temporary files older than DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed
+* during cron runs, but permanent files will not be removed during the file
+* garbage collection process.
+*/
+define('FILE_STATUS_PERMANENT', 1);
+/**
+* Provides Drupal stream wrapper registry.
+*
+* A stream wrapper is an abstraction of a file system that allows Drupal to
+* use the same set of methods to access both local files and remote resources.
+*
+* Provide a facility for managing and querying user-defined stream wrappers
+* in PHP. PHP's internal stream_get_wrappers() doesn't return the class
+* registered to handle a stream, which we need to be able to find the handler
+* for class instantiation.
+*
+* If a module registers a scheme that is already registered with PHP, the
+* existing scheme will be unregistered and replaced with the specified class.
+*
+* A stream is referenced as "scheme://target".
+*
+* The optional $filter parameter can be used to retrieve only the stream
+* wrappers that are appropriate for particular usage. For example, this returns
+* only stream wrappers that use local file storage:
+* @code
+*   $local_stream_wrappers = file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL);
+* @endcode
+*
+* The $filter parameter can only filter to types containing a particular flag.
+* In some cases, you may want to filter to types that do not contain a
+* particular flag. For example, you may want to retrieve all stream wrappers
+* that are not writable, or all stream wrappers that are not local. PHP's
+* array_diff_key() function can be used to help with this. For example, this
+* returns only stream wrappers that do not use local file storage:
+* @code
+*   $remote_stream_wrappers = array_diff_key(file_get_stream_wrappers(STREAM_WRAPPERS_ALL), file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL));
+* @endcode
+*
+* @param $filter
+*   (Optional) Filters out all types except those with an on bit for each on
+*   bit in $filter. For example, if $filter is STREAM_WRAPPERS_WRITE_VISIBLE,
+*   which is equal to (STREAM_WRAPPERS_READ | STREAM_WRAPPERS_WRITE |
+*   STREAM_WRAPPERS_VISIBLE), then only stream wrappers with all three of these
+*   bits set are returned. Defaults to STREAM_WRAPPERS_ALL, which returns all
+*   registered stream wrappers.
+*
+* @return
+*   An array keyed by scheme, with values containing an array of information
+*   about the stream wrapper, as returned by hook_stream_wrappers(). If $filter
+*   is omitted or set to STREAM_WRAPPERS_ALL, the entire Drupal stream wrapper
+*   registry is returned. Otherwise only the stream wrappers whose 'type'
+*   bitmask has an on bit for each bit specified in $filter are returned.
+*
+* @see hook_stream_wrappers()
+* @see hook_stream_wrappers_alter()
+*/
+function file_get_stream_wrappers($filter = STREAM_WRAPPERS_ALL) {
+$wrappers_storage = &drupal_static(__FUNCTION__);
+if (!isset($wrappers_storage)) {
+$wrappers = module_invoke_all('stream_wrappers');
+foreach ($wrappers as $scheme => $info) {
+// Add defaults.
+$wrappers[$scheme] += array('type' => STREAM_WRAPPERS_NORMAL);
+}
+drupal_alter('stream_wrappers', $wrappers);
+$existing = stream_get_wrappers();
+foreach ($wrappers as $scheme => $info) {
+// We only register classes that implement our interface.
+if (in_array('DrupalStreamWrapperInterface', class_implements($info['class']), TRUE)) {
+// Record whether we are overriding an existing scheme.
+if (in_array($scheme, $existing, TRUE)) {
+$wrappers[$scheme]['override'] = TRUE;
+stream_wrapper_unregister($scheme);
+}
+else {
+$wrappers[$scheme]['override'] = FALSE;
+}
+if (($info['type'] & STREAM_WRAPPERS_LOCAL) == STREAM_WRAPPERS_LOCAL) {
+stream_wrapper_register($scheme, $info['class']);
+}
+else {
+stream_wrapper_register($scheme, $info['class'], STREAM_IS_URL);
+}
+}
+// Pre-populate the static cache with the filters most typically used.
+$wrappers_storage[STREAM_WRAPPERS_ALL][$scheme] = $wrappers[$scheme];
+if (($info['type'] & STREAM_WRAPPERS_WRITE_VISIBLE) == STREAM_WRAPPERS_WRITE_VISIBLE) {
+$wrappers_storage[STREAM_WRAPPERS_WRITE_VISIBLE][$scheme] = $wrappers[$scheme];
+}
+}
+}
+if (!isset($wrappers_storage[$filter])) {
+$wrappers_storage[$filter] = array();
+foreach ($wrappers_storage[STREAM_WRAPPERS_ALL] as $scheme => $info) {
+// Bit-wise filter.
+if (($info['type'] & $filter) == $filter) {
+$wrappers_storage[$filter][$scheme] = $info;
+}
+}
+}
+return $wrappers_storage[$filter];
+}
+/**
+* Returns the stream wrapper class name for a given scheme.
+*
+* @param $scheme
+*   Stream scheme.
+*
+* @return
+*   Return string if a scheme has a registered handler, or FALSE.
+*/
+function file_stream_wrapper_get_class($scheme) {
+$wrappers = file_get_stream_wrappers();
+return empty($wrappers[$scheme]) ? FALSE : $wrappers[$scheme]['class'];
+}
+/**
+* Returns the scheme of a URI (e.g. a stream).
+*
+* @param $uri
+*   A stream, referenced as "scheme://target".
+*
+* @return
+*   A string containing the name of the scheme, or FALSE if none. For example,
+*   the URI "public://example.txt" would return "public".
+*
+* @see file_uri_target()
+*/
+function file_uri_scheme($uri) {
+$position = strpos($uri, '://');
+return $position ? substr($uri, 0, $position) : FALSE;
+}
+/**
+* Checks that the scheme of a stream URI is valid.
+*
+* Confirms that there is a registered stream handler for the provided scheme
+* and that it is callable. This is useful if you want to confirm a valid
+* scheme without creating a new instance of the registered handler.
+*
+* @param $scheme
+*   A URI scheme, a stream is referenced as "scheme://target".
+*
+* @return
+*   Returns TRUE if the string is the name of a validated stream,
+*   or FALSE if the scheme does not have a registered handler.
+*/
+function file_stream_wrapper_valid_scheme($scheme) {
+// Does the scheme have a registered handler that is callable?
+$class = file_stream_wrapper_get_class($scheme);
+if (class_exists($class)) {
+return TRUE;
+}
+else {
+return FALSE;
+}
+}
+/**
+* Returns the part of a URI after the schema.
+*
+* @param $uri
+*   A stream, referenced as "scheme://target".
+*
+* @return
+*   A string containing the target (path), or FALSE if none.
+*   For example, the URI "public://sample/test.txt" would return
+*   "sample/test.txt".
+*
+* @see file_uri_scheme()
+*/
+function file_uri_target($uri) {
+$data = explode('://', $uri, 2);
+// Remove erroneous leading or trailing, forward-slashes and backslashes.
+return count($data) == 2 ? trim($data[1], '\/') : FALSE;
+}
+/**
+* Gets the default file stream implementation.
+*
+* @return
+*   'public', 'private' or any other file scheme defined as the default.
+*/
+function file_default_scheme() {
+return variable_get('file_default_scheme', 'public');
+}
+/**
+* Normalizes a URI by making it syntactically correct.
+*
+* A stream is referenced as "scheme://target".
+*
+* The following actions are taken:
+* - Remove trailing slashes from target
+* - Trim erroneous leading slashes from target. e.g. ":///" becomes "://".
+*
+* @param $uri
+*   String reference containing the URI to normalize.
+*
+* @return
+*   The normalized URI.
+*/
+function file_stream_wrapper_uri_normalize($uri) {
+// Inline file_uri_scheme() function call for performance reasons.
+$position = strpos($uri, '://');
+$scheme = $position ? substr($uri, 0, $position) : FALSE;
+if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
+$target = file_uri_target($uri);
+if ($target !== FALSE) {
+$uri = $scheme . '://' . $target;
+}
+}
+return $uri;
+}
+/**
+* Returns a reference to the stream wrapper class responsible for a given URI.
+*
+* The scheme determines the stream wrapper class that should be
+* used by consulting the stream wrapper registry.
+*
+* @param $uri
+*   A stream, referenced as "scheme://target".
+*
+* @return
+*   Returns a new stream wrapper object appropriate for the given URI or FALSE
+*   if no registered handler could be found. For example, a URI of
+*   "private://example.txt" would return a new private stream wrapper object
+*   (DrupalPrivateStreamWrapper).
+*/
+function file_stream_wrapper_get_instance_by_uri($uri) {
+$scheme = file_uri_scheme($uri);
+$class = file_stream_wrapper_get_class($scheme);
+if (class_exists($class)) {
+$instance = new $class();
+$instance->setUri($uri);
+return $instance;
+}
+else {
+return FALSE;
+}
+}
+/**
+* Returns a reference to the stream wrapper class responsible for a scheme.
+*
+* This helper method returns a stream instance using a scheme. That is, the
+* passed string does not contain a "://". For example, "public" is a scheme
+* but "public://" is a URI (stream). This is because the later contains both
+* a scheme and target despite target being empty.
+*
+* Note: the instance URI will be initialized to "scheme://" so that you can
+* make the customary method calls as if you had retrieved an instance by URI.
+*
+* @param $scheme
+*   If the stream was "public://target", "public" would be the scheme.
+*
+* @return
+*   Returns a new stream wrapper object appropriate for the given $scheme.
+*   For example, for the public scheme a stream wrapper object
+*   (DrupalPublicStreamWrapper).
+*   FALSE is returned if no registered handler could be found.
+*/
+function file_stream_wrapper_get_instance_by_scheme($scheme) {
+$class = file_stream_wrapper_get_class($scheme);
+if (class_exists($class)) {
+$instance = new $class();
+$instance->setUri($scheme . '://');
+return $instance;
+}
+else {
+return FALSE;
+}
+}
+/**
+* Creates a web-accessible URL for a stream to an external or local file.
+*
+* Compatibility: normal paths and stream wrappers.
+*
+* There are two kinds of local files:
+* - "managed files", i.e. those stored by a Drupal-compatible stream wrapper.
+*   These are files that have either been uploaded by users or were generated
+*   automatically (for example through CSS aggregation).
+* - "shipped files", i.e. those outside of the files directory, which ship as
+*   part of Drupal core or contributed modules or themes.
+*
+* @param $uri
+*   The URI to a file for which we need an external URL, or the path to a
+*   shipped file.
+*
+* @return
+*   A string containing a URL that may be used to access the file.
+*   If the provided string already contains a preceding 'http', 'https', or
+*   '/', nothing is done and the same string is returned. If a stream wrapper
+*   could not be found to generate an external URL, then FALSE is returned.
+*
+* @see http://drupal.org/node/515192
+*/
+function file_create_url($uri) {
+// Allow the URI to be altered, e.g. to serve a file from a CDN or static
+// file server.
+drupal_alter('file_url', $uri);
+$scheme = file_uri_scheme($uri);
+if (!$scheme) {
+// Allow for:
+// - root-relative URIs (e.g. /foo.jpg in http://example.com/foo.jpg)
+// - protocol-relative URIs (e.g. //bar.jpg, which is expanded to
+//   http://example.com/bar.jpg by the browser when viewing a page over
+//   HTTP and to https://example.com/bar.jpg when viewing a HTTPS page)
+// Both types of relative URIs are characterized by a leading slash, hence
+// we can use a single check.
+if (drupal_substr($uri, 0, 1) == '/') {
+return $uri;
+}
+else {
+// If this is not a properly formatted stream, then it is a shipped file.
+// Therefore, return the urlencoded URI with the base URL prepended.
+return $GLOBALS['base_url'] . '/' . drupal_encode_path($uri);
+}
+}
+elseif ($scheme == 'http' || $scheme == 'https') {
+// Check for HTTP so that we don't have to implement getExternalUrl() for
+// the HTTP wrapper.
+return $uri;
+}
+else {
+// Attempt to return an external URL using the appropriate wrapper.
+if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
+return $wrapper->getExternalUrl();
+}
+else {
+return FALSE;
+}
+}
+}
+/**
+* Checks that the directory exists and is writable.
+*
+* Directories need to have execute permissions to be considered a directory by
+* FTP servers, etc.
+*
+* @param $directory
+*   A string reference containing the name of a directory path or URI. A
+*   trailing slash will be trimmed from a path.
+* @param $options
+*   A bitmask to indicate if the directory should be created if it does
+*   not exist (FILE_CREATE_DIRECTORY) or made writable if it is read-only
+*   (FILE_MODIFY_PERMISSIONS).
+*
+* @return
+*   TRUE if the directory exists (or was created) and is writable. FALSE
+*   otherwise.
+*/
+function file_prepare_directory(&$directory, $options = FILE_MODIFY_PERMISSIONS) {
+if (!file_stream_wrapper_valid_scheme(file_uri_scheme($directory))) {
+// Only trim if we're not dealing with a stream.
+$directory = rtrim($directory, '/\\');
+}
+// Check if directory exists.
+if (!is_dir($directory)) {
+// Let mkdir() recursively create directories and use the default directory
+// permissions.
+if (($options & FILE_CREATE_DIRECTORY) && @drupal_mkdir($directory, NULL, TRUE)) {
+return drupal_chmod($directory);
+}
+return FALSE;
+}
+// The directory exists, so check to see if it is writable.
+$writable = is_writable($directory);
+if (!$writable && ($options & FILE_MODIFY_PERMISSIONS)) {
+return drupal_chmod($directory);
+}
+return $writable;
+}
+/**
+* Creates a .htaccess file in each Drupal files directory if it is missing.
+*/
+function file_ensure_htaccess() {
+file_create_htaccess('public://', FALSE);
+if (variable_get('file_private_path', FALSE)) {
+file_create_htaccess('private://', TRUE);
+}
+file_create_htaccess('temporary://', TRUE);
+}
+/**
+* Creates a .htaccess file in the given directory.
+*
+* @param $directory
+*   The directory.
+* @param $private
+*   FALSE indicates that $directory should be an open and public directory.
+*   The default is TRUE which indicates a private and protected directory.
+* @param $force_overwrite
+*   Set to TRUE to attempt to overwrite the existing .htaccess file if one is
+*   already present. Defaults to FALSE.
+*/
+function file_create_htaccess($directory, $private = TRUE, $force_overwrite = FALSE) {
+if (file_uri_scheme($directory)) {
+$directory = file_stream_wrapper_uri_normalize($directory);
+}
+else {
+$directory = rtrim($directory, '/\\');
+}
+$htaccess_path =  $directory . '/.htaccess';
+if (file_exists($htaccess_path) && !$force_overwrite) {
+// Short circuit if the .htaccess file already exists.
+return;
+}
+$htaccess_lines = file_htaccess_lines($private);
+// Write the .htaccess file.
+if (file_put_contents($htaccess_path, $htaccess_lines)) {
+drupal_chmod($htaccess_path, 0444);
+}
+else {
+$variables = array('%directory' => $directory, '!htaccess' => '<br />' . nl2br(check_plain($htaccess_lines)));
+watchdog('security', "Security warning: Couldn't write .htaccess file. Please create a .htaccess file in your %directory directory which contains the following lines: <code>!htaccess</code>", $variables, WATCHDOG_ERROR);
+}
+}
+/**
+* Returns the standard .htaccess lines that Drupal writes to file directories.
+*
+* @param $private
+*   (Optional) Set to FALSE to return the .htaccess lines for an open and
+*   public directory. The default is TRUE, which returns the .htaccess lines
+*   for a private and protected directory.
+*
+* @return
+*   A string representing the desired contents of the .htaccess file.
+*
+* @see file_create_htaccess()
+*/
+function file_htaccess_lines($private = TRUE) {
+$lines = <<<EOF
+# Turn off all options we don't need.
+Options None
+Options +FollowSymLinks
+# Set the catch-all handler to prevent scripts from being executed.
+SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006
+<Files *>
+# Override the handler again if we're run later in the evaluation list.
+SetHandler Drupal_Security_Do_Not_Remove_See_SA_2013_003
+</Files>
+# If we know how to do it safely, disable the PHP engine entirely.
+<IfModule mod_php5.c>
+php_flag engine off
+</IfModule>
+EOF;
+if ($private) {
+$lines = <<<EOF
+# Deny all requests from Apache 2.4+.
+<IfModule mod_authz_core.c>
+Require all denied
+</IfModule>
+# Deny all requests from Apache 2.0-2.2.
+<IfModule !mod_authz_core.c>
+Deny from all
+</IfModule>
+EOF
+. "\n\n" . $lines;
+}
+return $lines;
+}
+/**
+* Loads file objects from the database.
+*
+* @param $fids
+*   An array of file IDs.
+* @param $conditions
+*   (deprecated) An associative array of conditions on the {file_managed}
+*   table, where the keys are the database fields and the values are the
+*   values those fields must have. Instead, it is preferable to use
+*   EntityFieldQuery to retrieve a list of entity IDs loadable by
+*   this function.
+*
+* @return
+*   An array of file objects, indexed by fid.
+*
+* @todo Remove $conditions in Drupal 8.
+*
+* @see hook_file_load()
+* @see file_load()
+* @see entity_load()
+* @see EntityFieldQuery
+*/
+function file_load_multiple($fids = array(), $conditions = array()) {
+return entity_load('file', $fids, $conditions);
+}
+/**
+* Loads a single file object from the database.
+*
+* @param $fid
+*   A file ID.
+*
+* @return
+*   An object representing the file, or FALSE if the file was not found.
+*
+* @see hook_file_load()
+* @see file_load_multiple()
+*/
+function file_load($fid) {
+$files = file_load_multiple(array($fid), array());
+return reset($files);
+}
+/**
+* Saves a file object to the database.
+*
+* If the $file->fid is not set a new record will be added.
+*
+* @param $file
+*   A file object returned by file_load().
+*
+* @return
+*   The updated file object.
+*
+* @see hook_file_insert()
+* @see hook_file_update()
+*/
+function file_save(stdClass $file) {
+$file->timestamp = REQUEST_TIME;
+$file->filesize = filesize($file->uri);
+// Load the stored entity, if any.
+if (!empty($file->fid) && !isset($file->original)) {
+$file->original = entity_load_unchanged('file', $file->fid);
+}
+module_invoke_all('file_presave', $file);
+module_invoke_all('entity_presave', $file, 'file');
+if (empty($file->fid)) {
+drupal_write_record('file_managed', $file);
+// Inform modules about the newly added file.
+module_invoke_all('file_insert', $file);
+module_invoke_all('entity_insert', $file, 'file');
+}
+else {
+drupal_write_record('file_managed', $file, 'fid');
+// Inform modules that the file has been updated.
+module_invoke_all('file_update', $file);
+module_invoke_all('entity_update', $file, 'file');
+}
+// Clear internal properties.
+unset($file->original);
+// Clear the static loading cache.
+entity_get_controller('file')->resetCache(array($file->fid));
+return $file;
+}
+/**
+* Determines where a file is used.
+*
+* @param $file
+*   A file object.
+*
+* @return
+*   A nested array with usage data. The first level is keyed by module name,
+*   the second by object type and the third by the object id. The value
+*   of the third level contains the usage count.
+*
+* @see file_usage_add()
+* @see file_usage_delete()
+*/
+function file_usage_list(stdClass $file) {
+$result = db_select('file_usage', 'f')
+->fields('f', array('module', 'type', 'id', 'count'))
+->condition('fid', $file->fid)
+->condition('count', 0, '>')
+->execute();
+$references = array();
+foreach ($result as $usage) {
+$references[$usage->module][$usage->type][$usage->id] = $usage->count;
+}
+return $references;
+}
+/**
+* Records that a module is using a file.
+*
+* This usage information will be queried during file_delete() to ensure that
+* a file is not in use before it is physically removed from disk.
+*
+* Examples:
+* - A module that associates files with nodes, so $type would be
+*   'node' and $id would be the node's nid. Files for all revisions are stored
+*   within a single nid.
+* - The User module associates an image with a user, so $type would be 'user'
+*   and the $id would be the user's uid.
+*
+* @param $file
+*   A file object.
+* @param $module
+*   The name of the module using the file.
+* @param $type
+*   The type of the object that contains the referenced file.
+* @param $id
+*   The unique, numeric ID of the object containing the referenced file.
+* @param $count
+*   (optional) The number of references to add to the object. Defaults to 1.
+*
+* @see file_usage_list()
+* @see file_usage_delete()
+*/
+function file_usage_add(stdClass $file, $module, $type, $id, $count = 1) {
+db_merge('file_usage')
+->key(array(
+'fid' => $file->fid,
+'module' => $module,
+'type' => $type,
+'id' => $id,
+))
+->fields(array('count' => $count))
+->expression('count', 'count + :count', array(':count' => $count))
+->execute();
+}
+/**
+* Removes a record to indicate that a module is no longer using a file.
+*
+* The file_delete() function is typically called after removing a file usage
+* to remove the record from the file_managed table and delete the file itself.
+*
+* @param $file
+*   A file object.
+* @param $module
+*   The name of the module using the file.
+* @param $type
+*   (optional) The type of the object that contains the referenced file. May
+*   be omitted if all module references to a file are being deleted.
+* @param $id
+*   (optional) The unique, numeric ID of the object containing the referenced
+*   file. May be omitted if all module references to a file are being deleted.
+* @param $count
+*   (optional) The number of references to delete from the object. Defaults to
+*   1. 0 may be specified to delete all references to the file within a
+*   specific object.
+*
+* @see file_usage_add()
+* @see file_usage_list()
+* @see file_delete()
+*/
+function file_usage_delete(stdClass $file, $module, $type = NULL, $id = NULL, $count = 1) {
+// Delete rows that have a exact or less value to prevent empty rows.
+$query = db_delete('file_usage')
+->condition('module', $module)
+->condition('fid', $file->fid);
+if ($type && $id) {
+$query
+->condition('type', $type)
+->condition('id', $id);
+}
+if ($count) {
+$query->condition('count', $count, '<=');
+}
+$result = $query->execute();
+// If the row has more than the specified count decrement it by that number.
+if (!$result && $count > 0) {
+$query = db_update('file_usage')
+->condition('module', $module)
+->condition('fid', $file->fid);
+if ($type && $id) {
+$query
+->condition('type', $type)
+->condition('id', $id);
+}
+$query->expression('count', 'count - :count', array(':count' => $count));
+$query->execute();
+}
+}
+/**
+* Copies a file to a new location and adds a file record to the database.
+*
+* This function should be used when manipulating files that have records
+* stored in the database. This is a powerful function that in many ways
+* performs like an advanced version of copy().
+* - Checks if $source and $destination are valid and readable/writable.
+* - If file already exists in $destination either the call will error out,
+*   replace the file or rename the file based on the $replace parameter.
+* - If the $source and $destination are equal, the behavior depends on the
+*   $replace parameter. FILE_EXISTS_REPLACE will error out. FILE_EXISTS_RENAME
+*   will rename the file until the $destination is unique.
+* - Adds the new file to the files database. If the source file is a
+*   temporary file, the resulting file will also be a temporary file. See
+*   file_save_upload() for details on temporary files.
+*
+* @param $source
+*   A file object.
+* @param $destination
+*   A string containing the destination that $source should be copied to.
+*   This must be a stream wrapper URI.
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
+*       the destination name exists then its database entry will be updated. If
+*       no database entry is found then a new one will be created.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   File object if the copy is successful, or FALSE in the event of an error.
+*
+* @see file_unmanaged_copy()
+* @see hook_file_copy()
+*/
+function file_copy(stdClass $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+if (!file_valid_uri($destination)) {
+if (($realpath = drupal_realpath($source->uri)) !== FALSE) {
+watchdog('file', 'File %file (%realpath) could not be copied, because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->uri, '%realpath' => $realpath, '%destination' => $destination));
+}
+else {
+watchdog('file', 'File %file could not be copied, because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->uri, '%destination' => $destination));
+}
+drupal_set_message(t('The specified file %file could not be copied, because the destination is invalid. More information is available in the system log.', array('%file' => $source->uri)), 'error');
+return FALSE;
+}
+if ($uri = file_unmanaged_copy($source->uri, $destination, $replace)) {
+$file = clone $source;
+$file->fid = NULL;
+$file->uri = $uri;
+$file->filename = drupal_basename($uri);
+// If we are replacing an existing file re-use its database record.
+if ($replace == FILE_EXISTS_REPLACE) {
+$existing_files = file_load_multiple(array(), array('uri' => $uri));
+if (count($existing_files)) {
+$existing = reset($existing_files);
+$file->fid = $existing->fid;
+$file->filename = $existing->filename;
+}
+}
+// If we are renaming around an existing file (rather than a directory),
+// use its basename for the filename.
+elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
+$file->filename = drupal_basename($destination);
+}
+$file = file_save($file);
+// Inform modules that the file has been copied.
+module_invoke_all('file_copy', $file, $source);
+return $file;
+}
+return FALSE;
+}
+/**
+* Determines whether the URI has a valid scheme for file API operations.
+*
+* There must be a scheme and it must be a Drupal-provided scheme like
+* 'public', 'private', 'temporary', or an extension provided with
+* hook_stream_wrappers().
+*
+* @param $uri
+*   The URI to be tested.
+*
+* @return
+*   TRUE if the URI is allowed.
+*/
+function file_valid_uri($uri) {
+// Assert that the URI has an allowed scheme. Barepaths are not allowed.
+$uri_scheme = file_uri_scheme($uri);
+if (empty($uri_scheme) || !file_stream_wrapper_valid_scheme($uri_scheme)) {
+return FALSE;
+}
+return TRUE;
+}
+/**
+* Copies a file to a new location without invoking the file API.
+*
+* This is a powerful function that in many ways performs like an advanced
+* version of copy().
+* - Checks if $source and $destination are valid and readable/writable.
+* - If file already exists in $destination either the call will error out,
+*   replace the file or rename the file based on the $replace parameter.
+* - If the $source and $destination are equal, the behavior depends on the
+*   $replace parameter. FILE_EXISTS_REPLACE will error out. FILE_EXISTS_RENAME
+*   will rename the file until the $destination is unique.
+* - Provides a fallback using realpaths if the move fails using stream
+*   wrappers. This can occur because PHP's copy() function does not properly
+*   support streams if safe_mode or open_basedir are enabled. See
+*   https://bugs.php.net/bug.php?id=60456
+*
+* @param $source
+*   A string specifying the filepath or URI of the source file.
+* @param $destination
+*   A URI containing the destination that $source should be copied to. The
+*   URI may be a bare filepath (without a scheme). If this value is omitted,
+*   Drupal's default files scheme will be used, usually "public://".
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   The path to the new file, or FALSE in the event of an error.
+*
+* @see file_copy()
+*/
+function file_unmanaged_copy($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+$original_source = $source;
+// Assert that the source file actually exists.
+if (!file_exists($source)) {
+// @todo Replace drupal_set_message() calls with exceptions instead.
+drupal_set_message(t('The specified file %file could not be copied, because no file by that name exists. Please check that you supplied the correct filename.', array('%file' => $original_source)), 'error');
+if (($realpath = drupal_realpath($original_source)) !== FALSE) {
+watchdog('file', 'File %file (%realpath) could not be copied because it does not exist.', array('%file' => $original_source, '%realpath' => $realpath));
+}
+else {
+watchdog('file', 'File %file could not be copied because it does not exist.', array('%file' => $original_source));
+}
+return FALSE;
+}
+// Build a destination URI if necessary.
+if (!isset($destination)) {
+$destination = file_build_uri(drupal_basename($source));
+}
+// Prepare the destination directory.
+if (file_prepare_directory($destination)) {
+// The destination is already a directory, so append the source basename.
+$destination = file_stream_wrapper_uri_normalize($destination . '/' . drupal_basename($source));
+}
+else {
+// Perhaps $destination is a dir/file?
+$dirname = drupal_dirname($destination);
+if (!file_prepare_directory($dirname)) {
+// The destination is not valid.
+watchdog('file', 'File %file could not be copied, because the destination directory %destination is not configured correctly.', array('%file' => $original_source, '%destination' => $dirname));
+drupal_set_message(t('The specified file %file could not be copied, because the destination directory is not properly configured. This may be caused by a problem with file or directory permissions. More information is available in the system log.', array('%file' => $original_source)), 'error');
+return FALSE;
+}
+}
+// Determine whether we can perform this operation based on overwrite rules.
+$destination = file_destination($destination, $replace);
+if ($destination === FALSE) {
+drupal_set_message(t('The file %file could not be copied because a file by that name already exists in the destination directory.', array('%file' => $original_source)), 'error');
+watchdog('file', 'File %file could not be copied because a file by that name already exists in the destination directory (%directory)', array('%file' => $original_source, '%directory' => $destination));
+return FALSE;
+}
+// Assert that the source and destination filenames are not the same.
+$real_source = drupal_realpath($source);
+$real_destination = drupal_realpath($destination);
+if ($source == $destination || ($real_source !== FALSE) && ($real_source == $real_destination)) {
+drupal_set_message(t('The specified file %file was not copied because it would overwrite itself.', array('%file' => $source)), 'error');
+watchdog('file', 'File %file could not be copied because it would overwrite itself.', array('%file' => $source));
+return FALSE;
+}
+// Make sure the .htaccess files are present.
+file_ensure_htaccess();
+// Perform the copy operation.
+if (!@copy($source, $destination)) {
+// If the copy failed and realpaths exist, retry the operation using them
+// instead.
+if ($real_source === FALSE || $real_destination === FALSE || !@copy($real_source, $real_destination)) {
+watchdog('file', 'The specified file %file could not be copied to %destination.', array('%file' => $source, '%destination' => $destination), WATCHDOG_ERROR);
+return FALSE;
+}
+}
+// Set the permissions on the new file.
+drupal_chmod($destination);
+return $destination;
+}
+/**
+* Constructs a URI to Drupal's default files location given a relative path.
+*/
+function file_build_uri($path) {
+$uri = file_default_scheme() . '://' . $path;
+return file_stream_wrapper_uri_normalize($uri);
+}
+/**
+* Determines the destination path for a file.
+*
+* @param $destination
+*   A string specifying the desired final URI or filepath.
+* @param $replace
+*   Replace behavior when the destination file already exists.
+*   - FILE_EXISTS_REPLACE - Replace the existing file.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   The destination filepath, or FALSE if the file already exists
+*   and FILE_EXISTS_ERROR is specified.
+*/
+function file_destination($destination, $replace) {
+if (file_exists($destination)) {
+switch ($replace) {
+case FILE_EXISTS_REPLACE:
+// Do nothing here, we want to overwrite the existing file.
+break;
+case FILE_EXISTS_RENAME:
+$basename = drupal_basename($destination);
+$directory = drupal_dirname($destination);
+$destination = file_create_filename($basename, $directory);
+break;
+case FILE_EXISTS_ERROR:
+// Error reporting handled by calling function.
+return FALSE;
+}
+}
+return $destination;
+}
+/**
+* Moves a file to a new location and update the file's database entry.
+*
+* Moving a file is performed by copying the file to the new location and then
+* deleting the original.
+* - Checks if $source and $destination are valid and readable/writable.
+* - Performs a file move if $source is not equal to $destination.
+* - If file already exists in $destination either the call will error out,
+*   replace the file or rename the file based on the $replace parameter.
+* - Adds the new file to the files database.
+*
+* @param $source
+*   A file object.
+* @param $destination
+*   A string containing the destination that $source should be moved to.
+*   This must be a stream wrapper URI.
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
+*       the destination name exists then its database entry will be updated and
+*       file_delete() called on the source file after hook_file_move is called.
+*       If no database entry is found then the source files record will be
+*       updated.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   Resulting file object for success, or FALSE in the event of an error.
+*
+* @see file_unmanaged_move()
+* @see hook_file_move()
+*/
+function file_move(stdClass $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+if (!file_valid_uri($destination)) {
+if (($realpath = drupal_realpath($source->uri)) !== FALSE) {
+watchdog('file', 'File %file (%realpath) could not be moved, because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->uri, '%realpath' => $realpath, '%destination' => $destination));
+}
+else {
+watchdog('file', 'File %file could not be moved, because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->uri, '%destination' => $destination));
+}
+drupal_set_message(t('The specified file %file could not be moved, because the destination is invalid. More information is available in the system log.', array('%file' => $source->uri)), 'error');
+return FALSE;
+}
+if ($uri = file_unmanaged_move($source->uri, $destination, $replace)) {
+$delete_source = FALSE;
+$file = clone $source;
+$file->uri = $uri;
+// If we are replacing an existing file re-use its database record.
+if ($replace == FILE_EXISTS_REPLACE) {
+$existing_files = file_load_multiple(array(), array('uri' => $uri));
+if (count($existing_files)) {
+$existing = reset($existing_files);
+$delete_source = TRUE;
+$file->fid = $existing->fid;
+}
+}
+// If we are renaming around an existing file (rather than a directory),
+// use its basename for the filename.
+elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
+$file->filename = drupal_basename($destination);
+}
+$file = file_save($file);
+// Inform modules that the file has been moved.
+module_invoke_all('file_move', $file, $source);
+if ($delete_source) {
+// Try a soft delete to remove original if it's not in use elsewhere.
+file_delete($source);
+}
+return $file;
+}
+return FALSE;
+}
+/**
+* Moves a file to a new location without database changes or hook invocation.
+*
+* @param $source
+*   A string specifying the filepath or URI of the original file.
+* @param $destination
+*   A string containing the destination that $source should be moved to.
+*   This must be a stream wrapper URI. If this value is omitted, Drupal's
+*   default files scheme will be used, usually "public://".
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   The URI of the moved file, or FALSE in the event of an error.
+*
+* @see file_move()
+*/
+function file_unmanaged_move($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+$filepath = file_unmanaged_copy($source, $destination, $replace);
+if ($filepath == FALSE || file_unmanaged_delete($source) == FALSE) {
+return FALSE;
+}
+return $filepath;
+}
+/**
+* Modifies a filename as needed for security purposes.
+*
+* Munging a file name prevents unknown file extensions from masking exploit
+* files. When web servers such as Apache decide how to process a URL request,
+* they use the file extension. If the extension is not recognized, Apache
+* skips that extension and uses the previous file extension. For example, if
+* the file being requested is exploit.php.pps, and Apache does not recognize
+* the '.pps' extension, it treats the file as PHP and executes it. To make
+* this file name safe for Apache and prevent it from executing as PHP, the
+* .php extension is "munged" into .php_, making the safe file name
+* exploit.php_.pps.
+*
+* Specifically, this function adds an underscore to all extensions that are
+* between 2 and 5 characters in length, internal to the file name, and not
+* included in $extensions.
+*
+* Function behavior is also controlled by the Drupal variable
+* 'allow_insecure_uploads'. If 'allow_insecure_uploads' evaluates to TRUE, no
+* alterations will be made, if it evaluates to FALSE, the filename is 'munged'.
+*
+* @param $filename
+*   File name to modify.
+* @param $extensions
+*   A space-separated list of extensions that should not be altered.
+* @param $alerts
+*   If TRUE, drupal_set_message() will be called to display a message if the
+*   file name was changed.
+*
+* @return
+*   The potentially modified $filename.
+*/
+function file_munge_filename($filename, $extensions, $alerts = TRUE) {
+$original = $filename;
+// Allow potentially insecure uploads for very savvy users and admin
+if (!variable_get('allow_insecure_uploads', 0)) {
+// Remove any null bytes. See http://php.net/manual/security.filesystem.nullbytes.php
+$filename = str_replace(chr(0), '', $filename);
+$whitelist = array_unique(explode(' ', strtolower(trim($extensions))));
+// Split the filename up by periods. The first part becomes the basename
+// the last part the final extension.
+$filename_parts = explode('.', $filename);
+$new_filename = array_shift($filename_parts); // Remove file basename.
+$final_extension = array_pop($filename_parts); // Remove final extension.
+// Loop through the middle parts of the name and add an underscore to the
+// end of each section that could be a file extension but isn't in the list
+// of allowed extensions.
+foreach ($filename_parts as $filename_part) {
+$new_filename .= '.' . $filename_part;
+if (!in_array(strtolower($filename_part), $whitelist) && preg_match("/^[a-zA-Z]{2,5}\d?$/", $filename_part)) {
+$new_filename .= '_';
+}
+}
+$filename = $new_filename . '.' . $final_extension;
+if ($alerts && $original != $filename) {
+drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $filename)));
+}
+}
+return $filename;
+}
+/**
+* Undoes the effect of file_munge_filename().
+*
+* @param $filename
+*   String with the filename to be unmunged.
+*
+* @return
+*   An unmunged filename string.
+*/
+function file_unmunge_filename($filename) {
+return str_replace('_.', '.', $filename);
+}
+/**
+* Creates a full file path from a directory and filename.
+*
+* If a file with the specified name already exists, an alternative will be
+* used.
+*
+* @param $basename
+*   String filename
+* @param $directory
+*   String containing the directory or parent URI.
+*
+* @return
+*   File path consisting of $directory and a unique filename based off
+*   of $basename.
+*/
+function file_create_filename($basename, $directory) {
+// Strip control characters (ASCII value < 32). Though these are allowed in
+// some filesystems, not many applications handle them well.
+$basename = preg_replace('/[\x00-\x1F]/u', '_', $basename);
+if (substr(PHP_OS, 0, 3) == 'WIN') {
+// These characters are not allowed in Windows filenames
+$basename = str_replace(array(':', '*', '?', '"', '<', '>', '|'), '_', $basename);
+}
+// A URI or path may already have a trailing slash or look like "public://".
+if (substr($directory, -1) == '/') {
+$separator = '';
+}
+else {
+$separator = '/';
+}
+$destination = $directory . $separator . $basename;
+if (file_exists($destination)) {
+// Destination file already exists, generate an alternative.
+$pos = strrpos($basename, '.');
+if ($pos !== FALSE) {
+$name = substr($basename, 0, $pos);
+$ext = substr($basename, $pos);
+}
+else {
+$name = $basename;
+$ext = '';
+}
+$counter = 0;
+do {
+$destination = $directory . $separator . $name . '_' . $counter++ . $ext;
+} while (file_exists($destination));
+}
+return $destination;
+}
+/**
+* Deletes a file and its database record.
+*
+* If the $force parameter is not TRUE, file_usage_list() will be called to
+* determine if the file is being used by any modules. If the file is being
+* used the delete will be canceled.
+*
+* @param $file
+*   A file object.
+* @param $force
+*   Boolean indicating that the file should be deleted even if the file is
+*   reported as in use by the file_usage table.
+*
+* @return mixed
+*   TRUE for success, FALSE in the event of an error, or an array if the file
+*   is being used by any modules.
+*
+* @see file_unmanaged_delete()
+* @see file_usage_list()
+* @see file_usage_delete()
+* @see hook_file_delete()
+*/
+function file_delete(stdClass $file, $force = FALSE) {
+if (!file_valid_uri($file->uri)) {
+if (($realpath = drupal_realpath($file->uri)) !== FALSE) {
+watchdog('file', 'File %file (%realpath) could not be deleted because it is not a valid URI. This may be caused by improper use of file_delete() or a missing stream wrapper.', array('%file' => $file->uri, '%realpath' => $realpath));
+}
+else {
+watchdog('file', 'File %file could not be deleted because it is not a valid URI. This may be caused by improper use of file_delete() or a missing stream wrapper.', array('%file' => $file->uri));
+}
+drupal_set_message(t('The specified file %file could not be deleted, because it is not a valid URI. More information is available in the system log.', array('%file' => $file->uri)), 'error');
+return FALSE;
+}
+// If any module still has a usage entry in the file_usage table, the file
+// will not be deleted, but file_delete() will return a populated array
+// that tests as TRUE.
+if (!$force && ($references = file_usage_list($file))) {
+return $references;
+}
+// Let other modules clean up any references to the deleted file.
+module_invoke_all('file_delete', $file);
+module_invoke_all('entity_delete', $file, 'file');
+// Make sure the file is deleted before removing its row from the
+// database, so UIs can still find the file in the database.
+if (file_unmanaged_delete($file->uri)) {
+db_delete('file_managed')->condition('fid', $file->fid)->execute();
+db_delete('file_usage')->condition('fid', $file->fid)->execute();
+entity_get_controller('file')->resetCache();
+return TRUE;
+}
+return FALSE;
+}
+/**
+* Deletes a file without database changes or hook invocations.
+*
+* This function should be used when the file to be deleted does not have an
+* entry recorded in the files table.
+*
+* @param $path
+*   A string containing a file path or (streamwrapper) URI.
+*
+* @return
+*   TRUE for success or path does not exist, or FALSE in the event of an
+*   error.
+*
+* @see file_delete()
+* @see file_unmanaged_delete_recursive()
+*/
+function file_unmanaged_delete($path) {
+if (is_dir($path)) {
+watchdog('file', '%path is a directory and cannot be removed using file_unmanaged_delete().', array('%path' => $path), WATCHDOG_ERROR);
+return FALSE;
+}
+if (is_file($path)) {
+return drupal_unlink($path);
+}
+// Return TRUE for non-existent file, but log that nothing was actually
+// deleted, as the current state is the intended result.
+if (!file_exists($path)) {
+watchdog('file', 'The file %path was not deleted, because it does not exist.', array('%path' => $path), WATCHDOG_NOTICE);
+return TRUE;
+}
+// We cannot handle anything other than files and directories. Log an error
+// for everything else (sockets, symbolic links, etc).
+watchdog('file', 'The file %path is not of a recognized type so it was not deleted.', array('%path' => $path), WATCHDOG_ERROR);
+return FALSE;
+}
+/**
+* Deletes all files and directories in the specified filepath recursively.
+*
+* If the specified path is a directory then the function will call itself
+* recursively to process the contents. Once the contents have been removed the
+* directory will also be removed.
+*
+* If the specified path is a file then it will be passed to
+* file_unmanaged_delete().
+*
+* Note that this only deletes visible files with write permission.
+*
+* @param $path
+*   A string containing either an URI or a file or directory path.
+*
+* @return
+*   TRUE for success or if path does not exist, FALSE in the event of an
+*   error.
+*
+* @see file_unmanaged_delete()
+*/
+function file_unmanaged_delete_recursive($path) {
+if (is_dir($path)) {
+$dir = dir($path);
+while (($entry = $dir->read()) !== FALSE) {
+if ($entry == '.' || $entry == '..') {
+continue;
+}
+$entry_path = $path . '/' . $entry;
+file_unmanaged_delete_recursive($entry_path);
+}
+$dir->close();
+return drupal_rmdir($path);
+}
+return file_unmanaged_delete($path);
+}
+/**
+* Determines total disk space used by a single user or the whole filesystem.
+*
+* @param $uid
+*   Optional. A user id, specifying NULL returns the total space used by all
+*   non-temporary files.
+* @param $status
+*   Optional. The file status to consider. The default is to only
+*   consider files in status FILE_STATUS_PERMANENT.
+*
+* @return
+*   An integer containing the number of bytes used.
+*/
+function file_space_used($uid = NULL, $status = FILE_STATUS_PERMANENT) {
+$query = db_select('file_managed', 'f');
+$query->condition('f.status', $status);
+$query->addExpression('SUM(f.filesize)', 'filesize');
+if (isset($uid)) {
+$query->condition('f.uid', $uid);
+}
+return $query->execute()->fetchField();
+}
+/**
+* Saves a file upload to a new location.
+*
+* The file will be added to the {file_managed} table as a temporary file.
+* Temporary files are periodically cleaned. To make the file a permanent file,
+* assign the status and use file_save() to save the changes.
+*
+* @param $form_field_name
+*   A string that is the associative array key of the upload form element in
+*   the form array.
+* @param $validators
+*   An optional, associative array of callback functions used to validate the
+*   file. See file_validate() for a full discussion of the array format.
+*   If no extension validator is provided it will default to a limited safe
+*   list of extensions which is as follows: "jpg jpeg gif png txt
+*   doc xls pdf ppt pps odt ods odp". To allow all extensions you must
+*   explicitly set the 'file_validate_extensions' validator to an empty array
+*   (Beware: this is not safe and should only be allowed for trusted users, if
+*   at all).
+* @param $destination
+*   A string containing the URI that the file should be copied to. This must
+*   be a stream wrapper URI. If this value is omitted, Drupal's temporary
+*   files scheme will be used ("temporary://").
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE: Replace the existing file.
+*   - FILE_EXISTS_RENAME: Append _{incrementing number} until the filename is
+*     unique.
+*   - FILE_EXISTS_ERROR: Do nothing and return FALSE.
+*
+* @return
+*   An object containing the file information if the upload succeeded, FALSE
+*   in the event of an error, or NULL if no file was uploaded. The
+*   documentation for the "File interface" group, which you can find under
+*   Related topics, or the header at the top of this file, documents the
+*   components of a file object. In addition to the standard components,
+*   this function adds:
+*   - source: Path to the file before it is moved.
+*   - destination: Path to the file after it is moved (same as 'uri').
+*/
+function file_save_upload($form_field_name, $validators = array(), $destination = FALSE, $replace = FILE_EXISTS_RENAME) {
+global $user;
+static $upload_cache;
+// Return cached objects without processing since the file will have
+// already been processed and the paths in _FILES will be invalid.
+if (isset($upload_cache[$form_field_name])) {
+return $upload_cache[$form_field_name];
+}
+// Make sure there's an upload to process.
+if (empty($_FILES['files']['name'][$form_field_name])) {
+return NULL;
+}
+// Check for file upload errors and return FALSE if a lower level system
+// error occurred. For a complete list of errors:
+// See http://php.net/manual/features.file-upload.errors.php.
+switch ($_FILES['files']['error'][$form_field_name]) {
+case UPLOAD_ERR_INI_SIZE:
+case UPLOAD_ERR_FORM_SIZE:
+drupal_set_message(t('The file %file could not be saved, because it exceeds %maxsize, the maximum allowed size for uploads.', array('%file' => $_FILES['files']['name'][$form_field_name], '%maxsize' => format_size(file_upload_max_size()))), 'error');
+return FALSE;
+case UPLOAD_ERR_PARTIAL:
+case UPLOAD_ERR_NO_FILE:
+drupal_set_message(t('The file %file could not be saved, because the upload did not complete.', array('%file' => $_FILES['files']['name'][$form_field_name])), 'error');
+return FALSE;
+case UPLOAD_ERR_OK:
+// Final check that this is a valid upload, if it isn't, use the
+// default error handler.
+if (is_uploaded_file($_FILES['files']['tmp_name'][$form_field_name])) {
+break;
+}
+// Unknown error
+default:
+drupal_set_message(t('The file %file could not be saved. An unknown error has occurred.', array('%file' => $_FILES['files']['name'][$form_field_name])), 'error');
+return FALSE;
+}
+// Begin building file object.
+$file = new stdClass();
+$file->uid      = $user->uid;
+$file->status   = 0;
+$file->filename = trim(drupal_basename($_FILES['files']['name'][$form_field_name]), '.');
+$file->uri      = $_FILES['files']['tmp_name'][$form_field_name];
+$file->filemime = file_get_mimetype($file->filename);
+$file->filesize = $_FILES['files']['size'][$form_field_name];
+$extensions = '';
+if (isset($validators['file_validate_extensions'])) {
+if (isset($validators['file_validate_extensions'][0])) {
+// Build the list of non-munged extensions if the caller provided them.
+$extensions = $validators['file_validate_extensions'][0];
+}
+else {
+// If 'file_validate_extensions' is set and the list is empty then the
+// caller wants to allow any extension. In this case we have to remove the
+// validator or else it will reject all extensions.
+unset($validators['file_validate_extensions']);
+}
+}
+else {
+// No validator was provided, so add one using the default list.
+// Build a default non-munged safe list for file_munge_filename().
+$extensions = 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp';
+$validators['file_validate_extensions'] = array();
+$validators['file_validate_extensions'][0] = $extensions;
+}
+if (!empty($extensions)) {
+// Munge the filename to protect against possible malicious extension hiding
+// within an unknown file type (ie: filename.html.foo).
+$file->filename = file_munge_filename($file->filename, $extensions);
+}
+// Rename potentially executable files, to help prevent exploits (i.e. will
+// rename filename.php.foo and filename.php to filename.php.foo.txt and
+// filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
+// evaluates to TRUE.
+if (!variable_get('allow_insecure_uploads', 0) && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->filename) && (substr($file->filename, -4) != '.txt')) {
+$file->filemime = 'text/plain';
+$file->uri .= '.txt';
+$file->filename .= '.txt';
+// The .txt extension may not be in the allowed list of extensions. We have
+// to add it here or else the file upload will fail.
+if (!empty($extensions)) {
+$validators['file_validate_extensions'][0] .= ' txt';
+drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $file->filename)));
+}
+}
+// If the destination is not provided, use the temporary directory.
+if (empty($destination)) {
+$destination = 'temporary://';
+}
+// Assert that the destination contains a valid stream.
+$destination_scheme = file_uri_scheme($destination);
+if (!$destination_scheme || !file_stream_wrapper_valid_scheme($destination_scheme)) {
+drupal_set_message(t('The file could not be uploaded, because the destination %destination is invalid.', array('%destination' => $destination)), 'error');
+return FALSE;
+}
+$file->source = $form_field_name;
+// A URI may already have a trailing slash or look like "public://".
+if (substr($destination, -1) != '/') {
+$destination .= '/';
+}
+$file->destination = file_destination($destination . $file->filename, $replace);
+// If file_destination() returns FALSE then $replace == FILE_EXISTS_ERROR and
+// there's an existing file so we need to bail.
+if ($file->destination === FALSE) {
+drupal_set_message(t('The file %source could not be uploaded because a file by that name already exists in the destination %directory.', array('%source' => $form_field_name, '%directory' => $destination)), 'error');
+return FALSE;
+}
+// Add in our check of the file name length.
+$validators['file_validate_name_length'] = array();
+// Call the validation functions specified by this function's caller.
+$errors = file_validate($file, $validators);
+// Check for errors.
+if (!empty($errors)) {
+$message = t('The specified file %name could not be uploaded.', array('%name' => $file->filename));
+if (count($errors) > 1) {
+$message .= theme('item_list', array('items' => $errors));
+}
+else {
+$message .= ' ' . array_pop($errors);
+}
+form_set_error($form_field_name, $message);
+return FALSE;
+}
+// Move uploaded files from PHP's upload_tmp_dir to Drupal's temporary
+// directory. This overcomes open_basedir restrictions for future file
+// operations.
+$file->uri = $file->destination;
+if (!drupal_move_uploaded_file($_FILES['files']['tmp_name'][$form_field_name], $file->uri)) {
+form_set_error($form_field_name, t('File upload error. Could not move uploaded file.'));
+watchdog('file', 'Upload error. Could not move uploaded file %file to destination %destination.', array('%file' => $file->filename, '%destination' => $file->uri));
+return FALSE;
+}
+// Set the permissions on the new file.
+drupal_chmod($file->uri);
+// If we are replacing an existing file re-use its database record.
+if ($replace == FILE_EXISTS_REPLACE) {
+$existing_files = file_load_multiple(array(), array('uri' => $file->uri));
+if (count($existing_files)) {
+$existing = reset($existing_files);
+$file->fid = $existing->fid;
+}
+}
+// If we made it this far it's safe to record this file in the database.
+if ($file = file_save($file)) {
+// Track non-public files in the session if they were uploaded by an
+// anonymous user. This allows modules such as the File module to only
+// grant view access to the specific anonymous user who uploaded the file.
+// See file_file_download().
+// The 'file_public_schema' variable is used to allow other publicly
+// accessible file schemes to be treated the same as the public:// scheme
+// provided by Drupal core and to avoid adding unnecessary data to the
+// session (and the resulting bypass of the page cache) in those cases. For
+// security reasons, only schemes that are completely publicly accessible,
+// with no download restrictions, should be added to this variable. See
+// file_managed_file_value().
+if (!$user->uid && !in_array($destination_scheme, variable_get('file_public_schema', array('public')))) {
+$_SESSION['anonymous_allowed_file_ids'][$file->fid] = $file->fid;
+}
+// Add file to the cache.
+$upload_cache[$form_field_name] = $file;
+return $file;
+}
+return FALSE;
+}
+/**
+* Moves an uploaded file to a new location.
+*
+* PHP's move_uploaded_file() does not properly support streams if safe_mode
+* or open_basedir are enabled, so this function fills that gap.
+*
+* Compatibility: normal paths and stream wrappers.
+*
+* @param $filename
+*   The filename of the uploaded file.
+* @param $uri
+*   A string containing the destination URI of the file.
+*
+* @return
+*   TRUE on success, or FALSE on failure.
+*
+* @see move_uploaded_file()
+* @see http://drupal.org/node/515192
+* @ingroup php_wrappers
+*/
+function drupal_move_uploaded_file($filename, $uri) {
+$result = @move_uploaded_file($filename, $uri);
+// PHP's move_uploaded_file() does not properly support streams if safe_mode
+// or open_basedir are enabled so if the move failed, try finding a real path
+// and retry the move operation.
+if (!$result) {
+if ($realpath = drupal_realpath($uri)) {
+$result = move_uploaded_file($filename, $realpath);
+}
+else {
+$result = move_uploaded_file($filename, $uri);
+}
+}
+return $result;
+}
+/**
+* Checks that a file meets the criteria specified by the validators.
+*
+* After executing the validator callbacks specified hook_file_validate() will
+* also be called to allow other modules to report errors about the file.
+*
+* @param $file
+*   A Drupal file object.
+* @param $validators
+*   An optional, associative array of callback functions used to validate the
+*   file. The keys are function names and the values arrays of callback
+*   parameters which will be passed in after the file object. The
+*   functions should return an array of error messages; an empty array
+*   indicates that the file passed validation. The functions will be called in
+*   the order specified.
+*
+* @return
+*   An array containing validation error messages.
+*
+* @see hook_file_validate()
+*/
+function file_validate(stdClass &$file, $validators = array()) {
+// Call the validation functions specified by this function's caller.
+$errors = array();
+foreach ($validators as $function => $args) {
+if (function_exists($function)) {
+array_unshift($args, $file);
+$errors = array_merge($errors, call_user_func_array($function, $args));
+}
+}
+// Let other modules perform validation on the new file.
+return array_merge($errors, module_invoke_all('file_validate', $file));
+}
+/**
+* Checks for files with names longer than we can store in the database.
+*
+* @param $file
+*   A Drupal file object.
+*
+* @return
+*   An array. If the file name is too long, it will contain an error message.
+*/
+function file_validate_name_length(stdClass $file) {
+$errors = array();
+if (empty($file->filename)) {
+$errors[] = t("The file's name is empty. Please give a name to the file.");
+}
+if (strlen($file->filename) > 240) {
+$errors[] = t("The file's name exceeds the 240 characters limit. Please rename the file and try again.");
+}
+return $errors;
+}
+/**
+* Checks that the filename ends with an allowed extension.
+*
+* @param $file
+*   A Drupal file object.
+* @param $extensions
+*   A string with a space separated list of allowed extensions.
+*
+* @return
+*   An array. If the file extension is not allowed, it will contain an error
+*   message.
+*
+* @see hook_file_validate()
+*/
+function file_validate_extensions(stdClass $file, $extensions) {
+$errors = array();
+$regex = '/\.(' . preg_replace('/ +/', '|', preg_quote($extensions)) . ')$/i';
+if (!preg_match($regex, $file->filename)) {
+$errors[] = t('Only files with the following extensions are allowed: %files-allowed.', array('%files-allowed' => $extensions));
+}
+return $errors;
+}
+/**
+* Checks that the file's size is below certain limits.
+*
+* @param $file
+*   A Drupal file object.
+* @param $file_limit
+*   An integer specifying the maximum file size in bytes. Zero indicates that
+*   no limit should be enforced.
+* @param $user_limit
+*   An integer specifying the maximum number of bytes the user is allowed.
+*   Zero indicates that no limit should be enforced.
+*
+* @return
+*   An array. If the file size exceeds limits, it will contain an error
+*   message.
+*
+* @see hook_file_validate()
+*/
+function file_validate_size(stdClass $file, $file_limit = 0, $user_limit = 0) {
+global $user;
+$errors = array();
+if ($file_limit && $file->filesize > $file_limit) {
+$errors[] = t('The file is %filesize exceeding the maximum file size of %maxsize.', array('%filesize' => format_size($file->filesize), '%maxsize' => format_size($file_limit)));
+}
+// Save a query by only calling file_space_used() when a limit is provided.
+if ($user_limit && (file_space_used($user->uid) + $file->filesize) > $user_limit) {
+$errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', array('%filesize' => format_size($file->filesize), '%quota' => format_size($user_limit)));
+}
+return $errors;
+}
+/**
+* Checks that the file is recognized by image_get_info() as an image.
+*
+* @param $file
+*   A Drupal file object.
+*
+* @return
+*   An array. If the file is not an image, it will contain an error message.
+*
+* @see hook_file_validate()
+*/
+function file_validate_is_image(stdClass $file) {
+$errors = array();
+$info = image_get_info($file->uri);
+if (!$info || empty($info['extension'])) {
+$errors[] = t('Only JPEG, PNG and GIF images are allowed.');
+}
+return $errors;
+}
+/**
+* Verifies that image dimensions are within the specified maximum and minimum.
+*
+* Non-image files will be ignored. If an image toolkit is available the image
+* will be scaled to fit within the desired maximum dimensions.
+*
+* @param $file
+*   A Drupal file object. This function may resize the file affecting its
+*   size.
+* @param $maximum_dimensions
+*   An optional string in the form WIDTHxHEIGHT e.g. '640x480' or '85x85'. If
+*   an image toolkit is installed the image will be resized down to these
+*   dimensions. A value of 0 indicates no restriction on size, so resizing
+*   will be attempted.
+* @param $minimum_dimensions
+*   An optional string in the form WIDTHxHEIGHT. This will check that the
+*   image meets a minimum size. A value of 0 indicates no restriction.
+*
+* @return
+*   An array. If the file is an image and did not meet the requirements, it
+*   will contain an error message.
+*
+* @see hook_file_validate()
+*/
+function file_validate_image_resolution(stdClass $file, $maximum_dimensions = 0, $minimum_dimensions = 0) {
+$errors = array();
+// Check first that the file is an image.
+if ($info = image_get_info($file->uri)) {
+if ($maximum_dimensions) {
+// Check that it is smaller than the given dimensions.
+list($width, $height) = explode('x', $maximum_dimensions);
+if ($info['width'] > $width || $info['height'] > $height) {
+// Try to resize the image to fit the dimensions.
+if ($image = image_load($file->uri)) {
+image_scale($image, $width, $height);
+image_save($image);
+$file->filesize = $image->info['file_size'];
+drupal_set_message(t('The image was resized to fit within the maximum allowed dimensions of %dimensions pixels.', array('%dimensions' => $maximum_dimensions)));
+}
+else {
+$errors[] = t('The image is too large; the maximum dimensions are %dimensions pixels.', array('%dimensions' => $maximum_dimensions));
+}
+}
+}
+if ($minimum_dimensions) {
+// Check that it is larger than the given dimensions.
+list($width, $height) = explode('x', $minimum_dimensions);
+if ($info['width'] < $width || $info['height'] < $height) {
+$errors[] = t('The image is too small; the minimum dimensions are %dimensions pixels.', array('%dimensions' => $minimum_dimensions));
+}
+}
+}
+return $errors;
+}
+/**
+* Saves a file to the specified destination and creates a database entry.
+*
+* @param $data
+*   A string containing the contents of the file.
+* @param $destination
+*   A string containing the destination URI. This must be a stream wrapper URI.
+*   If no value is provided, a randomized name will be generated and the file
+*   will be saved using Drupal's default files scheme, usually "public://".
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
+*       the destination name exists then its database entry will be updated. If
+*       no database entry is found then a new one will be created.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*       unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   A file object, or FALSE on error.
+*
+* @see file_unmanaged_save_data()
+*/
+function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+global $user;
+if (empty($destination)) {
+$destination = file_default_scheme() . '://';
+}
+if (!file_valid_uri($destination)) {
+watchdog('file', 'The data could not be saved because the destination %destination is invalid. This may be caused by improper use of file_save_data() or a missing stream wrapper.', array('%destination' => $destination));
+drupal_set_message(t('The data could not be saved, because the destination is invalid. More information is available in the system log.'), 'error');
+return FALSE;
+}
+if ($uri = file_unmanaged_save_data($data, $destination, $replace)) {
+// Create a file object.
+$file = new stdClass();
+$file->fid = NULL;
+$file->uri = $uri;
+$file->filename = drupal_basename($uri);
+$file->filemime = file_get_mimetype($file->uri);
+$file->uid      = $user->uid;
+$file->status   = FILE_STATUS_PERMANENT;
+// If we are replacing an existing file re-use its database record.
+if ($replace == FILE_EXISTS_REPLACE) {
+$existing_files = file_load_multiple(array(), array('uri' => $uri));
+if (count($existing_files)) {
+$existing = reset($existing_files);
+$file->fid = $existing->fid;
+$file->filename = $existing->filename;
+}
+}
+// If we are renaming around an existing file (rather than a directory),
+// use its basename for the filename.
+elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
+$file->filename = drupal_basename($destination);
+}
+return file_save($file);
+}
+return FALSE;
+}
+/**
+* Saves a string to the specified destination without invoking file API.
+*
+* This function is identical to file_save_data() except the file will not be
+* saved to the {file_managed} table and none of the file_* hooks will be
+* called.
+*
+* @param $data
+*   A string containing the contents of the file.
+* @param $destination
+*   A string containing the destination location. This must be a stream wrapper
+*   URI. If no value is provided, a randomized name will be generated and the
+*   file will be saved using Drupal's default files scheme, usually
+*   "public://".
+* @param $replace
+*   Replace behavior when the destination file already exists:
+*   - FILE_EXISTS_REPLACE - Replace the existing file.
+*   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
+*                          unique.
+*   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+*
+* @return
+*   A string with the path of the resulting file, or FALSE on error.
+*
+* @see file_save_data()
+*/
+function file_unmanaged_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
+// Write the data to a temporary file.
+$temp_name = drupal_tempnam('temporary://', 'file');
+if (file_put_contents($temp_name, $data) === FALSE) {
+drupal_set_message(t('The file could not be created.'), 'error');
+return FALSE;
+}
+// Move the file to its final destination.
+return file_unmanaged_move($temp_name, $destination, $replace);
+}
+/**
+* Transfers a file to the client using HTTP.
+*
+* Pipes a file through Drupal to the client.
+*
+* @param $uri
+*   String specifying the file URI to transfer.
+* @param $headers
+*   An array of HTTP headers to send along with file.
+*/
+function file_transfer($uri, $headers) {
+if (ob_get_level()) {
+ob_end_clean();
+}
+foreach ($headers as $name => $value) {
+drupal_add_http_header($name, $value);
+}
+drupal_send_headers();
+$scheme = file_uri_scheme($uri);
+// Transfer file in 1024 byte chunks to save memory usage.
+if ($scheme && file_stream_wrapper_valid_scheme($scheme) && $fd = fopen($uri, 'rb')) {
+while (!feof($fd)) {
+print fread($fd, 1024);
+}
+fclose($fd);
+}
+else {
+drupal_not_found();
+}
+drupal_exit();
+}
+/**
+* Menu handler for private file transfers.
+*
+* Call modules that implement hook_file_download() to find out if a file is
+* accessible and what headers it should be transferred with. If one or more
+* modules returned headers the download will start with the returned headers.
+* If a module returns -1 drupal_access_denied() will be returned. If the file
+* exists but no modules responded drupal_access_denied() will be returned.
+* If the file does not exist drupal_not_found() will be returned.
+*
+* @see system_menu()
+*/
+function file_download() {
+// Merge remainder of arguments from GET['q'], into relative file path.
+$args = func_get_args();
+$scheme = array_shift($args);
+$target = implode('/', $args);
+$uri = $scheme . '://' . $target;
+if (file_stream_wrapper_valid_scheme($scheme) && file_exists($uri)) {
+$headers = file_download_headers($uri);
+if (count($headers)) {
+file_transfer($uri, $headers);
+}
+drupal_access_denied();
+}
+else {
+drupal_not_found();
+}
+drupal_exit();
+}
+/**
+* Retrieves headers for a private file download.
+*
+* Calls all module implementations of hook_file_download() to retrieve headers
+* for files by the module that originally provided the file. The presence of
+* returned headers indicates the current user has access to the file.
+*
+* @param $uri
+*   The URI for the file whose headers should be retrieved.
+*
+* @return
+*   If access is allowed, headers for the file, suitable for passing to
+*   file_transfer(). If access is not allowed, an empty array will be returned.
+*
+* @see file_transfer()
+* @see file_download_access()
+* @see hook_file_download()
+*/
+function file_download_headers($uri) {
+// Let other modules provide headers and control access to the file.
+// module_invoke_all() uses array_merge_recursive() which merges header
+// values into a new array. To avoid that and allow modules to override
+// headers instead, use array_merge() to merge the returned arrays.
+$headers = array();
+foreach (module_implements('file_download') as $module) {
+$function = $module . '_file_download';
+$result = $function($uri);
+if ($result == -1) {
+// Throw away the headers received so far.
+$headers = array();
+break;
+}
+if (isset($result) && is_array($result)) {
+$headers = array_merge($headers, $result);
+}
+}
+return $headers;
+}
+/**
+* Checks that the current user has access to a particular file.
+*
+* The return value of this function hinges on the return value from
+* file_download_headers(), which is the function responsible for collecting
+* access information through hook_file_download().
+*
+* If immediately transferring the file to the browser and the headers will
+* need to be retrieved, the return value of file_download_headers() should be
+* used to determine access directly, so that access checks will not be run
+* twice.
+*
+* @param $uri
+*   The URI for the file whose access should be retrieved.
+*
+* @return
+*   Boolean TRUE if access is allowed. FALSE if access is not allowed.
+*
+* @see file_download_headers()
+* @see hook_file_download()
+*/
+function file_download_access($uri) {
+return count(file_download_headers($uri)) > 0;
+}
+/**
+* Finds all files that match a given mask in a given directory.
+*
+* Directories and files beginning with a period are excluded; this
+* prevents hidden files and directories (such as SVN working directories)
+* from being scanned.
+*
+* @param $dir
+*   The base directory or URI to scan, without trailing slash.
+* @param $mask
+*   The preg_match() regular expression of the files to find.
+* @param $options
+*   An associative array of additional options, with the following elements:
+*   - 'nomask': The preg_match() regular expression of the files to ignore.
+*     Defaults to '/(\.\.?|CVS)$/'.
+*   - 'callback': The callback function to call for each match. There is no
+*     default callback.
+*   - 'recurse': When TRUE, the directory scan will recurse the entire tree
+*     starting at the provided directory. Defaults to TRUE.
+*   - 'key': The key to be used for the returned associative array of files.
+*     Possible values are 'uri', for the file's URI; 'filename', for the
+*     basename of the file; and 'name' for the name of the file without the
+*     extension. Defaults to 'uri'.
+*   - 'min_depth': Minimum depth of directories to return files from. Defaults
+*     to 0.
+* @param $depth
+*   Current depth of recursion. This parameter is only used internally and
+*   should not be passed in.
+*
+* @return
+*   An associative array (keyed on the chosen key) of objects with 'uri',
+*   'filename', and 'name' members corresponding to the matching files.
+*/
+function file_scan_directory($dir, $mask, $options = array(), $depth = 0) {
+// Merge in defaults.
+$options += array(
+'nomask' => '/(\.\.?|CVS)$/',
+'callback' => 0,
+'recurse' => TRUE,
+'key' => 'uri',
+'min_depth' => 0,
+);
+$options['key'] = in_array($options['key'], array('uri', 'filename', 'name')) ? $options['key'] : 'uri';
+$files = array();
+if (is_dir($dir) && $handle = opendir($dir)) {
+while (FALSE !== ($filename = readdir($handle))) {
+if (!preg_match($options['nomask'], $filename) && $filename[0] != '.') {
+$uri = "$dir/$filename";
+$uri = file_stream_wrapper_uri_normalize($uri);
+if (is_dir($uri) && $options['recurse']) {
+// Give priority to files in this folder by merging them in after any subdirectory files.
+$files = array_merge(file_scan_directory($uri, $mask, $options, $depth + 1), $files);
+}
+elseif ($depth >= $options['min_depth'] && preg_match($mask, $filename)) {
+// Always use this match over anything already set in $files with the
+// same $$options['key'].
+$file = new stdClass();
+$file->uri = $uri;
+$file->filename = $filename;
+$file->name = pathinfo($filename, PATHINFO_FILENAME);
+$key = $options['key'];
+$files[$file->$key] = $file;
+if ($options['callback']) {
+$options['callback']($uri);
+}
+}
+}
+}
+closedir($handle);
+}
+return $files;
+}
+/**
+* Determines the maximum file upload size by querying the PHP settings.
+*
+* @return
+*   A file size limit in bytes based on the PHP upload_max_filesize and
+*   post_max_size
+*/
+function file_upload_max_size() {
+static $max_size = -1;
+if ($max_size < 0) {
+// Start with post_max_size.
+$max_size = parse_size(ini_get('post_max_size'));
+// If upload_max_size is less, then reduce. Except if upload_max_size is
+// zero, which indicates no limit.
+$upload_max = parse_size(ini_get('upload_max_filesize'));
+if ($upload_max > 0 && $upload_max < $max_size) {
+$max_size = $upload_max;
+}
+}
+return $max_size;
+}
+/**
+* Determines an Internet Media Type or MIME type from a filename.
+*
+* @param $uri
+*   A string containing the URI, path, or filename.
+* @param $mapping
+*   An optional map of extensions to their mimetypes, in the form:
+*    - 'mimetypes': a list of mimetypes, keyed by an identifier,
+*    - 'extensions': the mapping itself, an associative array in which
+*      the key is the extension (lowercase) and the value is the mimetype
+*      identifier. If $mapping is NULL file_mimetype_mapping() is called.
+*
+* @return
+*   The internet media type registered for the extension or
+*   application/octet-stream for unknown extensions.
+*
+* @see file_default_mimetype_mapping()
+*/
+function file_get_mimetype($uri, $mapping = NULL) {
+if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
+return $wrapper->getMimeType($uri, $mapping);
+}
+else {
+// getMimeType() is not implementation specific, so we can directly
+// call it without an instance.
+return DrupalLocalStreamWrapper::getMimeType($uri, $mapping);
+}
+}
+/**
+* Sets the permissions on a file or directory.
+*
+* This function will use the 'file_chmod_directory' and 'file_chmod_file'
+* variables for the default modes for directories and uploaded/generated
+* files. By default these will give everyone read access so that users
+* accessing the files with a user account without the webserver group (e.g.
+* via FTP) can read these files, and give group write permissions so webserver
+* group members (e.g. a vhost account) can alter files uploaded and owned by
+* the webserver.
+*
+* PHP's chmod does not support stream wrappers so we use our wrapper
+* implementation which interfaces with chmod() by default. Contrib wrappers
+* may override this behavior in their implementations as needed.
+*
+* @param $uri
+*   A string containing a URI file, or directory path.
+* @param $mode
+*   Integer value for the permissions. Consult PHP chmod() documentation for
+*   more information.
+*
+* @return
+*   TRUE for success, FALSE in the event of an error.
+*
+* @ingroup php_wrappers
+*/
+function drupal_chmod($uri, $mode = NULL) {
+if (!isset($mode)) {
+if (is_dir($uri)) {
+$mode = variable_get('file_chmod_directory', 0775);
+}
+else {
+$mode = variable_get('file_chmod_file', 0664);
+}
+}
+// If this URI is a stream, pass it off to the appropriate stream wrapper.
+// Otherwise, attempt PHP's chmod. This allows use of drupal_chmod even
+// for unmanaged files outside of the stream wrapper interface.
+if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
+if ($wrapper->chmod($mode)) {
+return TRUE;
+}
+}
+else {
+if (@chmod($uri, $mode)) {
+return TRUE;
+}
+}
+watchdog('file', 'The file permissions could not be set on %uri.', array('%uri' => $uri), WATCHDOG_ERROR);
+return FALSE;
+}
+/**
+* Deletes a file.
+*
+* PHP's unlink() is broken on Windows, as it can fail to remove a file
+* when it has a read-only flag set.
+*
+* @param $uri
+*   A URI or pathname.
+* @param $context
+*   Refer to http://php.net/manual/ref.stream.php
+*
+* @return
+*   Boolean TRUE on success, or FALSE on failure.
+*
+* @see unlink()
+* @ingroup php_wrappers
+*/
+function drupal_unlink($uri, $context = NULL) {
+$scheme = file_uri_scheme($uri);
+if ((!$scheme || !file_stream_wrapper_valid_scheme($scheme)) && (substr(PHP_OS, 0, 3) == 'WIN')) {
+chmod($uri, 0600);
+}
+if ($context) {
+return unlink($uri, $context);
+}
+else {
+return unlink($uri);
+}
+}
+/**
+* Resolves the absolute filepath of a local URI or filepath.
+*
+* The use of drupal_realpath() is discouraged, because it does not work for
+* remote URIs. Except in rare cases, URIs should not be manually resolved.
+*
+* Only use this function if you know that the stream wrapper in the URI uses
+* the local file system, and you need to pass an absolute path to a function
+* that is incompatible with stream URIs.
+*
+* @param string $uri
+*   A stream wrapper URI or a filepath, possibly including one or more symbolic
+*   links.
+*
+* @return string|false
+*   The absolute local filepath (with no symbolic links), or FALSE on failure.
+*
+* @see DrupalStreamWrapperInterface::realpath()
+* @see http://php.net/manual/function.realpath.php
+* @ingroup php_wrappers
+*/
+function drupal_realpath($uri) {
+// If this URI is a stream, pass it off to the appropriate stream wrapper.
+// Otherwise, attempt PHP's realpath. This allows use of drupal_realpath even
+// for unmanaged files outside of the stream wrapper interface.
+if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
+return $wrapper->realpath();
+}
+// Check that the URI has a value. There is a bug in PHP 5.2 on *BSD systems
+// that makes realpath not return FALSE as expected when passing an empty
+// variable.
+// @todo Remove when Drupal drops support for PHP 5.2.
+elseif (!empty($uri)) {
+return realpath($uri);
+}
+return FALSE;
+}
+/**
+* Gets the name of the directory from a given path.
+*
+* PHP's dirname() does not properly pass streams, so this function fills
+* that gap. It is backwards compatible with normal paths and will use
+* PHP's dirname() as a fallback.
+*
+* Compatibility: normal paths and stream wrappers.
+*
+* @param $uri
+*   A URI or path.
+*
+* @return
+*   A string containing the directory name.
+*
+* @see dirname()
+* @see http://drupal.org/node/515192
+* @ingroup php_wrappers
+*/
+function drupal_dirname($uri) {
+$scheme = file_uri_scheme($uri);
+if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
+return file_stream_wrapper_get_instance_by_scheme($scheme)->dirname($uri);
+}
+else {
+return dirname($uri);
+}
+}
+/**
+* Gets the filename from a given path.
+*
+* PHP's basename() does not properly support streams or filenames beginning
+* with a non-US-ASCII character.
+*
+* @see http://bugs.php.net/bug.php?id=37738
+* @see basename()
+*
+* @ingroup php_wrappers
+*/
+function drupal_basename($uri, $suffix = NULL) {
+$separators = '/';
+if (DIRECTORY_SEPARATOR != '/') {
+// For Windows OS add special separator.
+$separators .= DIRECTORY_SEPARATOR;
+}
+// Remove right-most slashes when $uri points to directory.
+$uri = rtrim($uri, $separators);
+// Returns the trailing part of the $uri starting after one of the directory
+// separators.
+$filename = preg_match('@[^' . preg_quote($separators, '@') . ']+$@', $uri, $matches) ? $matches[0] : '';
+// Cuts off a suffix from the filename.
+if ($suffix) {
+$filename = preg_replace('@' . preg_quote($suffix, '@') . '$@', '', $filename);
+}
+return $filename;
+}
+/**
+* Creates a directory using Drupal's default mode.
+*
+* PHP's mkdir() does not respect Drupal's default permissions mode. If a mode
+* is not provided, this function will make sure that Drupal's is used.
+*
+* Compatibility: normal paths and stream wrappers.
+*
+* @param $uri
+*   A URI or pathname.
+* @param $mode
+*   By default the Drupal mode is used.
+* @param $recursive
+*   Default to FALSE.
+* @param $context
+*   Refer to http://php.net/manual/ref.stream.php
+*
+* @return
+*   Boolean TRUE on success, or FALSE on failure.
+*
+* @see mkdir()
+* @see http://drupal.org/node/515192
+* @ingroup php_wrappers
+*/
+function drupal_mkdir($uri, $mode = NULL, $recursive = FALSE, $context = NULL) {
+if (!isset($mode)) {
+$mode = variable_get('file_chmod_directory', 0775);
+}
+if (!isset($context)) {
+return mkdir($uri, $mode, $recursive);
+}
+else {
+return mkdir($uri, $mode, $recursive, $context);
+}
+}
+/**
+* Removes a directory.
+*
+* PHP's rmdir() is broken on Windows, as it can fail to remove a directory
+* when it has a read-only flag set.
+*
+* @param $uri
+*   A URI or pathname.
+* @param $context
+*   Refer to http://php.net/manual/ref.stream.php
+*
+* @return
+*   Boolean TRUE on success, or FALSE on failure.
+*
+* @see rmdir()
+* @ingroup php_wrappers
+*/
+function drupal_rmdir($uri, $context = NULL) {
+$scheme = file_uri_scheme($uri);
+if ((!$scheme || !file_stream_wrapper_valid_scheme($scheme)) && (substr(PHP_OS, 0, 3) == 'WIN')) {
+chmod($uri, 0700);
+}
+if ($context) {
+return rmdir($uri, $context);
+}
+else {
+return rmdir($uri);
+}
+}
+/**
+* Creates a file with a unique filename in the specified directory.
+*
+* PHP's tempnam() does not return a URI like we want. This function
+* will return a URI if given a URI, or it will return a filepath if
+* given a filepath.
+*
+* Compatibility: normal paths and stream wrappers.
+*
+* @param $directory
+*   The directory where the temporary filename will be created.
+* @param $prefix
+*   The prefix of the generated temporary filename.
+*   Note: Windows uses only the first three characters of prefix.
+*
+* @return
+*   The new temporary filename, or FALSE on failure.
+*
+* @see tempnam()
+* @see http://drupal.org/node/515192
+* @ingroup php_wrappers
+*/
+function drupal_tempnam($directory, $prefix) {
+$scheme = file_uri_scheme($directory);
+if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
+$wrapper = file_stream_wrapper_get_instance_by_scheme($scheme);
+if ($filename = tempnam($wrapper->getDirectoryPath(), $prefix)) {
+return $scheme . '://' . drupal_basename($filename);
+}
+else {
+return FALSE;
+}
+}
+else {
+// Handle as a normal tempnam() call.
+return tempnam($directory, $prefix);
+}
+}
+/**
+* Gets the path of system-appropriate temporary directory.
+*/
+function file_directory_temp() {
+$temporary_directory = variable_get('file_temporary_path', NULL);
+if (empty($temporary_directory)) {
+$directories = array();
+// Has PHP been set with an upload_tmp_dir?
+if (ini_get('upload_tmp_dir')) {
+$directories[] = ini_get('upload_tmp_dir');
+}
+// Operating system specific dirs.
+if (substr(PHP_OS, 0, 3) == 'WIN') {
+$directories[] = 'c:\\windows\\temp';
+$directories[] = 'c:\\winnt\\temp';
+}
+else {
+$directories[] = '/tmp';
+}
+// PHP may be able to find an alternative tmp directory.
+// This function exists in PHP 5 >= 5.2.1, but Drupal
+// requires PHP 5 >= 5.2.0, so we check for it.
+if (function_exists('sys_get_temp_dir')) {
+$directories[] = sys_get_temp_dir();
+}
+foreach ($directories as $directory) {
+if (is_dir($directory) && is_writable($directory)) {
+$temporary_directory = $directory;
+break;
+}
+}
+if (empty($temporary_directory)) {
+// If no directory has been found default to 'files/tmp'.
+$temporary_directory = variable_get('file_public_path', conf_path() . '/files') . '/tmp';
+// Windows accepts paths with either slash (/) or backslash (\), but will
+// not accept a path which contains both a slash and a backslash. Since
+// the 'file_public_path' variable may have either format, we sanitize
+// everything to use slash which is supported on all platforms.
+$temporary_directory = str_replace('\\', '/', $temporary_directory);
+}
+// Save the path of the discovered directory.
+variable_set('file_temporary_path', $temporary_directory);
+}
+return $temporary_directory;
+}
+/**
+* Examines a file object and returns appropriate content headers for download.
+*
+* @param $file
+*   A file object.
+*
+* @return
+*   An associative array of headers, as expected by file_transfer().
+*/
+function file_get_content_headers($file) {
+$type = mime_header_encode($file->filemime);
+return array(
+'Content-Type' => $type,
+'Content-Length' => $file->filesize,
+'Cache-Control' => 'private',
+);
+}
+/**
+* @} End of "defgroup file".
+*/