File and Stream Guide: [
nsIScriptableIO | Accessing Files | Getting File Information | Reading from Files | Writing to Files | Moving, Copying and Deleting Files | Uploading and Downloading Files | Working With Directories ]
nsIScriptableIO), which was not available in any released version of the platform (pending some fixes). There are alternative XPCOM APIs you can use, your help in updating this pages to use the supported API is very much welcome!
Other documentation on files and I/O not using the unavailable nsIScriptableIO APIs: Code snippets: File I/O, Open and Save Dialogs, Reading textual data, Writing textual data, List of file-related error codes.
Files and Streams
This section describes how to access and get information about files, read from files and create and write files.
A XUL application or extension may access files on disk, and either read or write to files. A file is accessed via a File object. To get a reference to a File object use
nsIScriptableIO.getFile(). The following example will retrieve a reference to a file located in the profile directory named
var file = IO.getFile("Profile", "sample.txt");
nsIScriptableIO object is a global object always available within an application or extension. It provides a number of useful functions for dealing with files.
- Retrieve a File Object
- For information about getting a File Object, see Accessing Files
- Get Information about a File
- Available information about a file include the permissions, size, and last modified date of a file. See Getting File Information for more details.
- Reading from a File
- For information about reading from text and binary files, see Reading from Files.
- Writing to a File
- For information about writing to text and binary files, see Writing to Files.
- Copying and Moving Files
- Files may be moved and copied on disk. For details, see Copying a File and Moving a File.
- Deleting Files
- To learn how to delete a file, see Deleting a File.
- Open and Save Dialogs
- You can show a dialog to the user to allow them to select a file to open or enter a filename for saving. For details about this, see Open and Save Dialogs.
- File Errors
- See File Errors for a list of errors that might occur while using files.
Working With Directories
Directories may be accessed in a similar manner using
nsIScriptableIO.getFile(). For instance, in the following example, a subdirectory is retrieved. If the name 'subdirname' refers to a directory, then the returned object will refer to this directory. The returned value is still a
nsIFile object, however a number of methods may be used which are only of value for subdirectories.
var file = IO.getFile("Profile", "subdirname");
For more information about using directories, see Working with Directories. Specifically, to create a directory, see Creating Directories and to retrieve a list of files or subdirectories within a directory, see Iterating over the Files in a Directory.