IDBFS is provides a POSIX-like file system interface for browser-based JavaScript. * [idbfs.js](https://raw.github.com/js-platform/idbfs/develop/dist/idbfs.js) * [idbfs.min.js](https://raw.github.com/js-platform/idbfs/develop/dist/idbfs.min.js) ### Getting Started IDBFS is partly based on the `fs` module from node.js. The API is asynchronous and most methods require the caller to provide a callback function. Errors are passed to callbacks through the first parameter. To create a new file system or open an existing one, create a new `FileSystem` instance and pass the name of the file system. A new IndexedDB database is created for each file system. #### Example ```` ```` As with node.js, there is no guarantee that file system operations will be executed in the order they are invoked. Ensure proper ordering by chaining operations in callbacks. ### API Reference Callbacks for methods that accept them are non-optional. The first callback parameter is reserved for passing errors. It will be `undefined` if no errors occurred and should always be checked. #### IDBFS.FileSystem(name, flags) File system constructor, invoked to open an existing file system or create a new one. Accepts a name and optional flags. Use `'FORMAT'` to force IDBFS for format the file system. #### fs.stat(path, callback) Asynchronous stat(2). Callback gets `(error, stats)`, where `stats` is an object like { node: // internal node id (unique) dev: // file system name size: // file size in bytes nlinks: // number of links atime: // last access time mtime: // last modified time ctime: // creation time type: // file type (FILE, DIRECTORY, ...) } #### fs.fstat(fd, callback) Asynchronous stat(2). Callback gets `(error, stats)`. See `fs.stat`. #### fs.link(oldpath, newpath, callback) Asynchronous link(2). Callback gets no additional agruments. #### fs.unlink(path, callback) Asynchronous unlink(2). Callback gets no additional agruments. #### fs.rmdir(path, callback) Asynchronous rmdir(2). Callback gets no additional agruments. #### fs.mkdir(path, callback) Asynchronous mkdir(2). Callback gets no additional agruments. #### fs.close(fd, callback) Asynchronous close(2). Callback gets no additional agruments. #### fs.open(path, flags, callback) Asynchronous open(2). Flags can be * `'r'`: Open file for reading. An exception occurs if the file does not exist. * `'r+'`: Open file for reading and writing. An exception occurs if the file does not exist. * `'w'`: Open file for writing. The file is created (if it does not exist) or truncated (if it exists). * `'w+'`: Open file for reading and writing. The file is created (if it does not exist) or truncated (if it exists). * `'a'`: Open file for appending. The file is created if it does not exist. * `'a+'`: Open file for reading and appending. The file is created if it does not exist. Callback gets `(error, fd)`, where `fd` is the file descriptor. Unlike node.js, IDBFS does not accept the optional `mode` parameter since it doesn't yet implement file permissions. #### fs.write(fd, buffer, offset, length, position, callback) Write bytes from `buffer` to the file specified by `fd`, where `offset` and `length` describe the part of the buffer to be written. The `position` refers to the offset from the beginning of the file where this data should be written. If `position` is `null`, the data will be written at the current position. See pwrite(2). The callback gets `(error, nbytes)`, where `nbytes` is the number of bytes written. #### fs.writeFile(filename, data, [options], callback) Asynchronously writes data to a file. `data` can be a string or a buffer, in which case any encoding option is ignored. The `options` argument is optional, and can take the form `"utf8"` (i.e., an encoding) or be an object literal: `{ encoding: "utf8", flag: "w" }`. If no encoding is specified, and `data` is a string, the encoding defaults to `'utf8'`. The callback gets `(error)`. ```javascript // Write UTF8 text file fs.writeFile('/myfile.txt', "...data...", function (err) { if (err) throw err; }); // Write binary file fs.writeFile('/myfile', buffer, function (err) { if (err) throw err; }); ``` #### fs.read(fd, buffer, offset, length, position, callback) Read bytes from the file specified by `fd` into `buffer`, where `offset` and `length` describe the part of the buffer to be used. The `position` refers to the offset from the beginning of the file where this data should be read. If `position` is `null`, the data will be written at the current position. See pread(2). The callback gets `(error, nbytes)`, where `nbytes` is the number of bytes read. #### fs.readFile(filename, [options], callback) Asynchronously reads the entire contents of a file. The `options` argument is optional, and can take the form `"utf8"` (i.e., an encoding) or be an object literal: `{ encoding: "utf8", flag: "r" }`. If no encoding is specified, the raw binary buffer is returned on the callback. The callback gets `(error, data)`, where data is the contents of the file. ```javascript // Read UTF8 text file fs.readFile('/myfile.txt', 'utf8', function (err, data) { if (err) throw err; console.log(data); }); // Read binary file fs.readFile('/myfile.txt', function (err, data) { if (err) throw err; console.log(data); }); ``` #### fs.lseek(fd, offset, whence, callback) Asynchronous lseek(2), where `whence` can be `SET`, `CUR`, or `END`. Callback gets `(error, pos)`, where `pos` is the resulting offset, in bytes, from the beginning of the file. #### fs.readdir(path, callback) Asynchronous readdir(3). Reads the contents of a directory. Callback gets `(error, files)`, where `files` is an array containing the names of each file in the directory, excluding `.` and `..`.