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<?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 = "Deny from all\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;

  $original_destination = $destination;

  // 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