File Helper
***********

The File Helper file contains functions that assist in working with
files.

* Loading this Helper

* Available Functions


Loading this Helper
===================

This helper is loaded using the following code:

   $this->load->helper('file');


Available Functions
===================

The following functions are available:

read_file($file)

   Parameters:
      * **$file** ("string") – File path

   Returns:
      File contents or FALSE on failure

   Return type:
      "string"

   Returns the data contained in the file specified in the path.

   Example:

      $string = read_file('./path/to/file.php');

   The path can be a relative or full server path. Returns FALSE
   (boolean) on failure.

   Note:

     The path is relative to your main site index.php file, NOT your
     controller or view files. CodeIgniter uses a front controller so
     paths are always relative to the main site index.

   Note:

     This function is DEPRECATED. Use the native "file_get_contents()"
     instead.

   Important:

     If your server is running an **open_basedir** restriction this
     function might not work if you are trying to access a file above
     the calling script.

write_file($path, $data[, $mode = 'wb'])

   Parameters:
      * **$path** ("string") – File path

      * **$data** ("string") – Data to write to file

      * **$mode** ("string") – "fopen()" mode

   Returns:
      TRUE if the write was successful, FALSE in case of an error

   Return type:
      "bool"

   Writes data to the file specified in the path. If the file does not
   exist then the function will create it.

   Example:

      $data = 'Some file data';
      if ( ! write_file('./path/to/file.php', $data))
      {
              echo 'Unable to write the file';
      }
      else
      {
              echo 'File written!';
      }

   You can optionally set the write mode via the third parameter:

      write_file('./path/to/file.php', $data, 'r+');

   The default mode is ‘wb’. Please see the PHP user guide for mode
   options.

   Note:

     The path is relative to your main site index.php file, NOT your
     controller or view files. CodeIgniter uses a front controller so
     paths are always relative to the main site index.

   Note:

     This function acquires an exclusive lock on the file while
     writing to it.

delete_files($path[, $del_dir = FALSE[, $htdocs = FALSE]])

   Parameters:
      * **$path** ("string") – Directory path

      * **$del_dir** ("bool") – Whether to also delete directories

      * **$htdocs** ("bool") – Whether to skip deleting .htaccess and
        index page files

   Returns:
      TRUE on success, FALSE in case of an error

   Return type:
      "bool"

   Deletes ALL files contained in the supplied path.

   Example:

      delete_files('./path/to/directory/');

   If the second parameter is set to TRUE, any directories contained
   within the supplied root path will be deleted as well.

   Example:

      delete_files('./path/to/directory/', TRUE);

   Note:

     The files must be writable or owned by the system in order to be
     deleted.

get_filenames($source_dir[, $include_path = FALSE])

   Parameters:
      * **$source_dir** ("string") – Directory path

      * **$include_path** ("bool") – Whether to include the path as
        part of the filenames

   Returns:
      An array of file names

   Return type:
      "array"

   Takes a server path as input and returns an array containing the
   names of all files contained within it. The file path can
   optionally be added to the file names by setting the second
   parameter to TRUE.

   Example:

      $controllers = get_filenames(APPPATH.'controllers/');

get_dir_file_info($source_dir, $top_level_only)

   Parameters:
      * **$source_dir** ("string") – Directory path

      * **$top_level_only** ("bool") – Whether to look only at the
        specified directory (excluding sub-directories)

   Returns:
      An array containing info on the supplied directory’s contents

   Return type:
      "array"

   Reads the specified directory and builds an array containing the
   filenames, filesize, dates, and permissions. Sub-folders contained
   within the specified path are only read if forced by sending the
   second parameter to FALSE, as this can be an intensive operation.

   Example:

      $models_info = get_dir_file_info(APPPATH.'models/');

get_file_info($file[, $returned_values = array('name', 'server_path', 'size', 'date')])

   Parameters:
      * **$file** ("string") – File path

      * **$returned_values** ("array") – What type of info to return

   Returns:
      An array containing info on the specified file or FALSE on
      failure

   Return type:
      "array"

   Given a file and path, returns (optionally) the *name*, *path*,
   *size* and *date modified* information attributes for a file.
   Second parameter allows you to explicitly declare what information
   you want returned.

   Valid "$returned_values" options are: *name*, *size*, *date*,
   *readable*, *writeable*, *executable* and *fileperms*.

get_mime_by_extension($filename)

   Parameters:
      * **$filename** ("string") – File name

   Returns:
      MIME type string or FALSE on failure

   Return type:
      "string"

   Translates a filename extension into a MIME type based on
   *config/mimes.php*. Returns FALSE if it can’t determine the type,
   or read the MIME config file.

      $file = 'somefile.png';
      echo $file.' is has a mime type of '.get_mime_by_extension($file);

   Note:

     This is not an accurate way of determining file MIME types, and
     is here strictly for convenience. It should not be used for
     security purposes.

symbolic_permissions($perms)

   Parameters:
      * **$perms** ("int") – Permissions

   Returns:
      Symbolic permissions string

   Return type:
      "string"

   Takes numeric permissions (such as is returned by "fileperms()")
   and returns standard symbolic notation of file permissions.

      echo symbolic_permissions(fileperms('./index.php'));  // -rw-r--r--

octal_permissions($perms)

   Parameters:
      * **$perms** ("int") – Permissions

   Returns:
      Octal permissions string

   Return type:
      "string"

   Takes numeric permissions (such as is returned by "fileperms()")
   and returns a three character octal notation of file permissions.

      echo octal_permissions(fileperms('./index.php')); // 644
