system.pathForFile()

Type Function
Library system.*
Return value String
Revision 2017.3145
Keywords system directory
See also Reading and Writing Files (guide)
system.ApplicationSupportDirectory
system.CachesDirectory
system.DocumentsDirectory
system.ResourceDirectory
system.TemporaryDirectory

Overview

Generates an absolute path using system-defined directories as the base. An additional optional parameter, baseDirectory, specifies which base directory is used to construct the full path, with its default value being system.ResourceDirectory.

This function is intended for use with file I/O APIs, not for display/media APIs that require a baseDir or baseDirectory parameter.

Syntax

system.pathForFile( filename [, baseDirectory] )
filename (required)

String. The name of the file, or a path to the file that is relative to baseDirectory. Alternatively, pass nil to get the path to baseDirectory.

baseDirectory (optional)

Constant. Constant corresponding to the base directory where the file is located. Default value is system.ResourceDirectory if the parameter is not provided.

Gotchas

General

If the base directory is system.ResourceDirectory and the generated path points to a non-existent file, nil is returned and a warning message is displayed in the Corona Simulator Console.

Android File Restrictions

File access in Corona is based on the underlining operating system which varies by platform. On iOS devices, you can access files in all of the directories described above. On Android, however, there is no literal system.ResourceDirectory because all resource files reside inside a compressed .apk file.

Corona allows direct loading of images and audio files using the appropriate APIs, but it has limited access to resource files on Android using the file I/O APIs. Specifically, the following types can not be read from the resources directory: .html, .htm, .3gp, .lua, .m4v, .mp4, .png, .jpg, and .ttf.

Because of this limitation, if you have files of these types bundled in the core directory that you need to copy to another directory, you must change the file name so it can be accessed by the file I/O APIs. For example, if you want to move cat.png from the resource directory to the documents directory, it must be renamed cat.png.txt to be copied. See the Reading and Writing Files guide for more information and examples.

Examples

Get Path to Specific File
local path = system.pathForFile( "data.txt", system.DocumentsDirectory )
local fhd = io.open( path )
 
-- Determine if file exists
if fhd then
   print( "File exists" )
   fhd:close()
else
    print( "File does not exist!" )
end
Get Path to Base Directory
local path = system.pathForFile( nil, system.DocumentsDirectory )
print( path )