Expo FileSystem

A library that provides access to the local file system on the device.

Android

iOS

tvOS

Included in Expo Go

Bundled version:

~18.1.11

expo-file-system provides access to a file system stored locally on the device. It is also capable of uploading and downloading files from network URLs.

Diagram explaining how expo-file-system interacts with different resources

Diagram of the various pieces of expo-file-system and how they interact with different resources

How expo-file-system works differently inside of the Expo Go app

Within Expo Go, each project has a separate file system scope and has no access to the file system of other projects.

Installation

Terminal

- npx expo install expo-file-system

If you are installing this in an existing React Native app, make sure to install expo in your project.

Usage

Downloading files

Component.js

const callback = downloadProgress => {
  const progress = downloadProgress.totalBytesWritten / downloadProgress.totalBytesExpectedToWrite;
  this.setState({
    downloadProgress: progress,
  });
};

const downloadResumable = FileSystem.createDownloadResumable(
  'http://techslides.com/demos/sample-videos/small.mp4',
  FileSystem.documentDirectory + 'small.mp4',
  {},
  callback
);

try {
  const { uri } = await downloadResumable.downloadAsync();
  console.log('Finished downloading to ', uri);
} catch (e) {
  console.error(e);
}

try {
  await downloadResumable.pauseAsync();
  console.log('Paused download operation, saving for future retrieval');
  AsyncStorage.setItem('pausedDownload', JSON.stringify(downloadResumable.savable()));
} catch (e) {
  console.error(e);
}

try {
  const { uri } = await downloadResumable.resumeAsync();
  console.log('Finished downloading to ', uri);
} catch (e) {
  console.error(e);
}

//To resume a download across app restarts, assuming the DownloadResumable.savable() object was stored:
const downloadSnapshotJson = await AsyncStorage.getItem('pausedDownload');
const downloadSnapshot = JSON.parse(downloadSnapshotJson);
const downloadResumable = new FileSystem.DownloadResumable(
  downloadSnapshot.url,
  downloadSnapshot.fileUri,
  downloadSnapshot.options,
  callback,
  downloadSnapshot.resumeData
);

try {
  const { uri } = await downloadResumable.resumeAsync();
  console.log('Finished downloading to ', uri);
} catch (e) {
  console.error(e);
}

Managing Giphy's

Giphy example

import * as FileSystem from 'expo-file-system';

const gifDir = FileSystem.cacheDirectory + 'giphy/';
const gifFileUri = (gifId: string) => gifDir + `gif_${gifId}_200.gif`;
const gifUrl = (gifId: string) => `https://media1.giphy.com/media/${gifId}/200.gif`;

// Checks if gif directory exists. If not, creates it
async function ensureDirExists() {
  const dirInfo = await FileSystem.getInfoAsync(gifDir);
  if (!dirInfo.exists) {
    console.log("Gif directory doesn't exist, creating…");
    await FileSystem.makeDirectoryAsync(gifDir, { intermediates: true });
  }
}

// Downloads all gifs specified as array of IDs
export async function addMultipleGifs(gifIds: string[]) {
  try {
    await ensureDirExists();

    console.log('Downloading', gifIds.length, 'gif files…');
    await Promise.all(gifIds.map(id => FileSystem.downloadAsync(gifUrl(id), gifFileUri(id))));
  } catch (e) {
    console.error("Couldn't download gif files:", e);
  }
}

// Returns URI to our local gif file
// If our gif doesn't exist locally, it downloads it
export async function getSingleGif(gifId: string) {
  await ensureDirExists();

  const fileUri = gifFileUri(gifId);
  const fileInfo = await FileSystem.getInfoAsync(fileUri);

  if (!fileInfo.exists) {
    console.log("Gif isn't cached locally. Downloading…");
    await FileSystem.downloadAsync(gifUrl(gifId), fileUri);
  }

  return fileUri;
}

// Exports shareable URI - it can be shared outside your app
export async function getGifContentUri(gifId: string) {
  return FileSystem.getContentUriAsync(await getSingleGif(gifId));
}

// Deletes whole giphy directory with all its content
export async function deleteAllGifs() {
  console.log('Deleting all GIF files…');
  await FileSystem.deleteAsync(gifDir);
}

Server: handling multipart requests

The simple server in Node.js, which can save uploaded images to disk:

index.js

const express = require('express');
const app = express();
const fs = require('fs');
const multer = require('multer');
const upload = multer({ dest: 'uploads/' });

// This method will save the binary content of the request as a file.
app.patch('/binary-upload', (req, res) => {
  req.pipe(fs.createWriteStream('./uploads/image' + Date.now() + '.png'));
  res.end('OK');
});

// This method will save a "photo" field from the request as a file.
app.patch('/multipart-upload', upload.single('photo'), (req, res) => {
  // You can access other HTTP parameters. They are located in the body object.
  console.log(req.body);
  res.end('OK');
});

app.listen(3000, () => {
  console.log('Working on port 3000');
});

API

import * as FileSystem from 'expo-file-system';

Directories

The API takes file:// URIs pointing to local files on the device to identify files. Each app only has read and write access to locations under the following directories:

So, for example, the URI to a file named 'myFile' under 'myDirectory' in the app's user documents directory would be FileSystem.documentDirectory + 'myDirectory/myFile'.

Expo APIs that create files generally operate within these directories. This includes Audio recordings, Camera photos, ImagePicker results, SQLite databases and takeSnapShotAsync() results. This allows their use with the FileSystem API.

Some FileSystem functions are able to read from (but not write to) other locations.

SAF URI

A SAF URI is a URI that is compatible with the Storage Access Framework. It should look like this content://com.android.externalstorage.*. The easiest way to obtain such URI is by requestDirectoryPermissionsAsync method.

Classes

`Directory`

Android

iOS

tvOS

Type: Class extends FileSystemDirectory

Represents a directory on the filesystem.

A Directory instance can be created for any path, and does not need to exist on the filesystem during creation.

The constructor accepts an array of strings that are joined to create the directory URI. The first argument can also be a Directory instance (like Paths.cache).

Example

const directory = new Directory(Paths.cache, "subdirName");

Directory Properties

`exists`

Android

iOS

tvOS

Type: boolean

A boolean representing if a directory exists and can be accessed.

`size`

Android

iOS

tvOS

Literal type: union

A size of the directory in bytes. Null if the directory does not exist, or it cannot be read.

Acceptable values are: null | number

`uri`

Android

iOS

tvOS

Read Only • Type: string

Represents the directory URI. The field is read-only, but it may change as a result of calling some methods such as move.

`name`

Android

iOS

tvOS

Type: string

Directory name.

`parentDirectory`

Android

iOS

tvOS

Type: Directory

Directory containing the file.

Directory Methods

`copy(destination)`

Android

iOS

tvOS

Parameter	Type
destination	`Directory \| File`

Copies a directory.

Returns:

void

`create(options)`

Android

iOS

tvOS

Parameter	Type
options(optional)	`DirectoryCreateOptions`

Creates a directory that the current uri points to.

Returns:

void

`createDirectory(name)`

Android

iOS

tvOS

Parameter	Type
name	`string`

Returns:

Directory

`createFile(name, mimeType)`

Android

iOS

tvOS

Parameter	Type
name	`string`
mimeType	`null \| string`

Returns:

File

`delete()`

Android

iOS

tvOS

Deletes a directory. Also deletes all files and directories inside the directory.

Returns:

void

`info()`

Android

iOS

tvOS

Retrieves an object containing properties of a directory.

Returns:

DirectoryInfo

An object with directory metadata (for example, size, creation date, and so on).

`list()`

Android

iOS

tvOS

Lists the contents of a directory. Calling this method if the parent directory does not exist will throw an error.

Returns:

(File | Directory)[]

An array of Directory and File instances.

`move(destination)`

Android

iOS

tvOS

Parameter	Type
destination	`Directory \| File`

Moves a directory. Updates the uri property that now points to the new location.

Returns:

void

`pickDirectoryAsync(initialUri)`

Android

iOS

tvOS

Parameter	Type	Description
initialUri(optional)	`string`	An optional uri pointing to an initial folder on which the directory picker is opened.

A static method that opens a file picker to select a directory.

On iOS, the selected directory grants temporary read and write access for the current app session only. After the app restarts, you must prompt the user again to regain access.

Returns:

Promise<Directory>

a Directory instance. On Android, the underlying uri will be a content URI.

`rename(newName)`

Android

iOS

tvOS

Parameter	Type
newName	`string`

Renames a directory.

Returns:

void

`File`

Android

iOS

tvOS

Type: Class extends FileSystemFile implements Blob

Represents a file on the filesystem.

A File instance can be created for any path, and does not need to exist on the filesystem during creation.

The constructor accepts an array of strings that are joined to create the file URI. The first argument can also be a Directory instance (like Paths.cache) or a File instance (which creates a new reference to the same file).

Example

const file = new File(Paths.cache, "subdirName", "file.txt");

File Properties

`creationTime`

Android

iOS

tvOS

Literal type: union

A creation time of the file expressed in milliseconds since epoch. Returns null if the file does not exist, cannot be read or the Android version is earlier than API 26.

Acceptable values are: null | number

`exists`

Android

iOS

tvOS

Type: boolean

A boolean representing if a file exists. true if the file exists, false otherwise. Also, false if the application does not have read access to the file.

`md5`

Android

iOS

tvOS

Literal type: union

A md5 hash of the file. Null if the file does not exist, or it cannot be read.

Acceptable values are: null | string

`modificationTime`

Android

iOS

tvOS

Literal type: union

A last modification time of the file expressed in milliseconds since epoch. Returns a Null if the file does not exist, or it cannot be read.

Acceptable values are: null | number

`size`

Android

iOS

tvOS

Type: number

A size of the file in bytes. 0 if the file does not exist, or it cannot be read.

`type`

Android

iOS

tvOS

Type: string

A mime type of the file. An empty string if the file does not exist, or it cannot be read.

`uri`

Android

iOS

tvOS

Read Only • Type: string

Represents the file URI. The field is read-only, but it may change as a result of calling some methods such as move.

`extension`

Android

iOS

tvOS

Type: string

File extension.

Example

'.png'

`name`

Android

iOS

tvOS

Type: string

File name. Includes the extension.

`parentDirectory`

Android

iOS

tvOS

Type: Directory

Directory containing the file.

File Methods

`arrayBuffer()`

Android

iOS

tvOS

The arrayBuffer() method of the Blob interface returns a Promise that resolves with the contents of the blob as binary data contained in an ArrayBuffer.

MDN Reference

Returns:

Promise<ArrayBuffer>

`base64()`

Android

iOS

tvOS

Retrieves content of the file as base64.

Returns:

Promise<string>

A promise that resolves with the contents of the file as a base64 string.

`base64Sync()`

Android

iOS

tvOS

Retrieves content of the file as base64.

Returns:

string

The contents of the file as a base64 string.

`bytes()`

Android

iOS

tvOS

Retrieves byte content of the entire file.

Returns:

Promise<Uint8Array<ArrayBuffer>>

A promise that resolves with the contents of the file as a Uint8Array.

`bytesSync()`

Android

iOS

tvOS

Retrieves byte content of the entire file.

Returns:

Uint8Array

The contents of the file as a Uint8Array.

`copy(destination)`

Android

iOS

tvOS

Parameter	Type
destination	`Directory \| File`

Copies a file.

Returns:

void

`create(options)`

Android

iOS

tvOS

Parameter	Type
options(optional)	`FileCreateOptions`

Creates a file.

Returns:

void

`delete()`

Android

iOS

tvOS

Deletes a file.

Returns:

void

`downloadFileAsync(url, destination, options)`

Android

iOS

tvOS

Parameter	Type	Description
url	`string`	The URL of the file to download.
destination	`Directory \| File`	The destination directory or file. If a directory is provided, the resulting filename will be determined based on the response headers.
options(optional)	`DownloadOptions`	Download options. When the destination already contains a file, the promise rejects with a `DestinationAlreadyExists` error unless `options.idempotent` is set to `true`. With `idempotent: true`, the download overwrites the existing file instead of failing.

A static method that downloads a file from the network.

On Android, the response body streams directly into the target file. If the download fails after it starts, a partially written file may remain at the destination. On iOS, the download first completes in a temporary location and the file is moved into place only after success, so no file is left behind when the request fails.

Returns:

Promise<File>

A promise that resolves to the downloaded file. When the server responds with a non-2xx HTTP status, the promise rejects with an UnableToDownload error whose message includes the status code. No file is created in that scenario.

Example

const file = await File.downloadFileAsync("https://example.com/image.png", new Directory(Paths.document));

`info(options)`

Android

iOS

tvOS

Parameter	Type
options(optional)	`InfoOptions`

Retrieves an object containing properties of a file

Returns:

FileInfo

An object with file metadata (for example, size, creation date, and so on).

`move(destination)`

Android

iOS

tvOS

Parameter	Type
destination	`Directory \| File`

Moves a directory. Updates the uri property that now points to the new location.

Returns:

void

`open()`

Android

iOS

tvOS

Returns A FileHandle object that can be used to read and write data to the file.

Returns:

FileHandle

`pickFileAsync(initialUri, mimeType)`

Android

iOS

tvOS

Parameter	Type	Description
initialUri(optional)	`string`	An optional URI pointing to an initial folder on which the file picker is opened.
mimeType(optional)	`string`	A mime type that is used to filter out files that can be picked out.

A static method that opens a file picker to select a single file of specified type. On iOS, it returns a temporary copy of the file leaving the original file untouched.

Selecting multiple files is not supported yet.

Returns:

Promise<File | File[]>

A File instance or an array of File instances.

`readableStream()`

Android

iOS

tvOS

Returns:

ReadableStream<Uint8Array<ArrayBuffer>>

`rename(newName)`

Android

iOS

tvOS

Parameter	Type
newName	`string`

Renames a file.

Returns:

void

`slice(start, end, contentType)`

Android

iOS

tvOS

Parameter	Type
start(optional)	`number`
end(optional)	`number`
contentType(optional)	`string`

The slice() method of the Blob interface creates and returns a new Blob object which contains data from a subset of the blob on which it's called.

MDN Reference

Returns:

Blob

`stream()`

Android

iOS

tvOS

The stream() method of the Blob interface returns a ReadableStream which upon reading returns the data contained within the Blob.

MDN Reference

Returns:

ReadableStream<Uint8Array<ArrayBuffer>>

`text()`

Android

iOS

tvOS

Retrieves text from the file.

Returns:

Promise<string>

A promise that resolves with the contents of the file as string.

`textSync()`

Android

iOS

tvOS

Retrieves text from the file.

Returns:

string

The contents of the file as string.

`writableStream()`

Android

iOS

tvOS

Returns:

WritableStream<Uint8Array>

`write(content)`

Android

iOS

tvOS

Parameter	Type	Description
content	`string \| Uint8Array`	The content to write into the file.

Writes content to the file.

Returns:

void

`FileHandle`

Android

iOS

tvOS

FileHandle Properties

`offset`

Android

iOS

tvOS

Literal type: union

A property that indicates the current byte offset in the file. Calling readBytes or writeBytes will read or write a specified amount of bytes starting from this offset. The offset is incremented by the number of bytes read or written. The offset can be set to any value within the file size. If the offset is set to a value greater than the file size, the next write operation will append data to the end of the file. Null if the file handle is closed.

Acceptable values are: null | number

`size`

Android

iOS

tvOS

Literal type: union

A size of the file in bytes or null if the file handle is closed.

Acceptable values are: null | number

FileHandle Methods

`close()`

Android

iOS

tvOS

Closes the file handle. This allows the file to be deleted, moved or read by a different process. Subsequent calls to readBytes or writeBytes will throw an error.

Returns:

void

`readBytes(length)`

Android

iOS

tvOS

Parameter	Type	Description
length	`number`	The number of bytes to read.

Reads the specified amount of bytes from the file at the current offset.

Returns:

Uint8Array<ArrayBuffer>

`writeBytes(bytes)`

Android

iOS

tvOS

Parameter	Type	Description
bytes	`Uint8Array`	A `Uint8Array` array containing bytes to write.

Writes the specified bytes to the file at the current offset.

Returns:

void

`Paths`

Android

iOS

tvOS

Type: Class extends PathUtilities

Paths Properties

`appleSharedContainers`

Android

iOS

tvOS

Type: Record<string, Directory>

`availableDiskSpace`

Android

iOS

tvOS

Type: number

A property that represents the available space on device's internal storage, represented in bytes.

`bundle`

Android

iOS

tvOS

Type: Directory

A property containing the bundle directory – the directory where assets bundled with the application are stored.

`cache`

Android

iOS

tvOS

Type: Directory

A property containing the cache directory – a place to store files that can be deleted by the system when the device runs low on storage.

`document`

Android

iOS

tvOS

Type: Directory

A property containing the document directory – a place to store files that are safe from being deleted by the system.

`totalDiskSpace`

Android

iOS

tvOS

Type: number

A property that represents the total space on device's internal storage, represented in bytes.

Paths Methods

`basename(path, ext)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to get the base name from.
ext(optional)	`string`	An optional file extension.

Returns the base name of a path.

Returns:

string

A string representing the base name.

`dirname(path)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to get the directory name from.

Returns the directory name of a path.

Returns:

string

A string representing the directory name.

`extname(path)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to get the extension from.

Returns the extension of a path.

Returns:

string

A string representing the extension.

`info(...uris)`

Android

iOS

tvOS

Parameter	Type
...uris	`string[]`

Returns an object that indicates if the specified path represents a directory.

Returns:

PathInfo

`isAbsolute(path)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to check.

Checks if a path is absolute.

Returns:

boolean

true if the path is absolute, false otherwise.

`join(...paths)`

Android

iOS

tvOS

Parameter	Type	Description
...paths	`(string \| File \| Directory)[]`	An array of path segments.

Joins path segments into a single path.

Returns:

string

A string representing the joined path.

`normalize(path)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to normalize.

Normalizes a path.

Returns:

string

A string representing the normalized path.

`parse(path)`

Android

iOS

tvOS

Parameter	Type	Description
path	`string \| File \| Directory`	The path to parse.

Parses a path into its components.

Returns:

{
  base: string, 
  dir: string, 
  ext: string, 
  name: string, 
  root: string
}

An object containing the parsed path components.

`relative(from, to)`

Android

iOS

tvOS

Parameter	Type	Description
from	`string \| File \| Directory`	The base path.
to	`string \| File \| Directory`	The relative path.

Resolves a relative path to an absolute path.

Returns:

string

A string representing the resolved path.

Methods

Deprecated: Use new File().copy() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.copyAsync(options)`

Android

iOS

tvOS

Parameter	Type
options	`RelocatingOptions`

Returns:

Promise<void>

Deprecated: Import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.createDownloadResumable(uri, fileUri, options, callback, resumeData)`

Android

iOS

tvOS

Parameter	Type
uri	`string`
fileUri	`string`
options(optional)	`DownloadOptions`
callback(optional)	`FileSystemNetworkTaskProgressCallback<DownloadProgressData>`
resumeData(optional)	`string`

Returns:

any

Deprecated: Import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.createUploadTask(url, fileUri, options, callback)`

Android

iOS

tvOS

Parameter	Type
url	`string`
fileUri	`string`
options(optional)	`FileSystemUploadOptions`
callback(optional)	`FileSystemNetworkTaskProgressCallback<UploadProgressData>`

Returns:

any

Deprecated: Use new File().delete() or new Directory().delete() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.deleteAsync(fileUri, options)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`
options(optional)	`DeletingOptions`

Returns:

Promise<void>

Deprecated

`FileSystem.deleteLegacyDocumentDirectoryAndroid()`

Android

iOS

tvOS

Returns:

Promise<void>

Deprecated: Use File.downloadFileAsync or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.downloadAsync(uri, fileUri, options)`

Android

iOS

tvOS

Parameter	Type
uri	`string`
fileUri	`string`
options(optional)	`DownloadOptions`

Returns:

Promise<FileSystemDownloadResult>

Deprecated: Import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.getContentUriAsync(fileUri)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`

Returns:

Promise<string>

Deprecated: Use Paths.availableDiskSpace or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.getFreeDiskStorageAsync()`

Android

iOS

tvOS

Returns:

Promise<number>

Deprecated: Use new File().info or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.getInfoAsync(fileUri, options)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`
options(optional)	`InfoOptions`

Returns:

Promise<FileInfo>

Deprecated: Use Paths.totalDiskSpace or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.getTotalDiskCapacityAsync()`

Android

iOS

tvOS

Returns:

Promise<number>

Deprecated: Use new Directory().create() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.makeDirectoryAsync(fileUri, options)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`
options(optional)	`MakeDirectoryOptions`

Returns:

Promise<void>

Deprecated: Use new File().move() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.moveAsync(options)`

Android

iOS

tvOS

Parameter	Type
options	`RelocatingOptions`

Returns:

Promise<void>

Deprecated: Use new File().text() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.readAsStringAsync(fileUri, options)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`
options(optional)	`ReadingOptions`

Returns:

Promise<string>

Deprecated: Use new Directory().list() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.readDirectoryAsync(fileUri)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`

Returns:

Promise<string[]>

Deprecated: Use @expo/fetch or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.uploadAsync(url, fileUri, options)`

Android

iOS

tvOS

Parameter	Type
url	`string`
fileUri	`string`
options(optional)	`FileSystemUploadOptions`

Returns:

Promise<FileSystemUploadResult>

Deprecated: Use new File().write() or import this method from expo-file-system/legacy. This method will throw in runtime.

`FileSystem.writeAsStringAsync(fileUri, contents, options)`

Android

iOS

tvOS

Parameter	Type
fileUri	`string`
contents	`string`
options(optional)	`WritingOptions`

Returns:

Promise<void>

Types

`DirectoryCreateOptions`

Android

iOS

tvOS

Property	Type	Description
idempotent(optional)	`boolean`	This flag controls whether the `create` operation is idempotent (safe to call multiple times without error). If `true`, creating a file or directory that already exists will succeed silently. If `false`, an error will be thrown when the target already exists. Default:`false`
intermediates(optional)	`boolean`	Whether to create intermediate directories if they do not exist. Default:`false`
overwrite(optional)	`boolean`	Whether to overwrite the directory if it exists. Default:`false`

`DirectoryInfo`

Android

iOS

tvOS

Property	Type	Description
creationTime(optional)	`number`	A creation time of the directory expressed in milliseconds since epoch. Returns null if the Android version is earlier than API 26.
exists	`boolean`	Indicates whether the directory exists.
files(optional)	`string[]`	A list of file names contained within a directory.
modificationTime(optional)	`number`	The last modification time of the directory expressed in milliseconds since epoch.
size(optional)	`number`	The size of the file in bytes.
uri(optional)	`string`	A `file://` URI pointing to the directory.

`DownloadOptions`

Android

iOS

tvOS

Property	Type	Description
headers(optional)	`undefined`	The headers to send with the request.
idempotent(optional)	`boolean`	This flag controls whether the `download` operation is idempotent (safe to call multiple times without error). If `true`, downloading a file that already exists overwrites the previous one. If `false`, an error is thrown when the target file already exists. Default:`false`

`FileCreateOptions`

Android

iOS

tvOS

Property	Type	Description
intermediates(optional)	`boolean`	Whether to create intermediate directories if they do not exist. Default:`false`
overwrite(optional)	`boolean`	Whether to overwrite the file if it exists. Default:`false`

`FileInfo`

Android

iOS

tvOS

Property	Type	Description
creationTime(optional)	`number`	A creation time of the file expressed in milliseconds since epoch. Returns null if the Android version is earlier than API 26.
exists	`boolean`	Indicates whether the file exists.
md5(optional)	`string`	Present if the `md5` option was truthy. Contains the MD5 hash of the file.
modificationTime(optional)	`number`	The last modification time of the file expressed in milliseconds since epoch.
size(optional)	`number`	The size of the file in bytes.
uri(optional)	`string`	A `file://` URI pointing to the file. This is the same as the `fileUri` input parameter.

`InfoOptions`

Android

iOS

tvOS

Property	Type	Description
md5(optional)	`boolean`	Whether to return the MD5 hash of the file. Default:`false`

`PathInfo`

Android

iOS

tvOS

Property	Type	Description
exists	`boolean`	Indicates whether the path exists. Returns true if it exists; false if the path does not exist or if there is no read permission.
isDirectory	`boolean \| null`	Indicates whether the path is a directory. Returns true or false if the path exists; otherwise, returns null.

Supported URI schemes

In this table, you can see what type of URI can be handled by each method. For example, if you have an URI, which begins with content://, you cannot use FileSystem.readAsStringAsync(), but you can use FileSystem.copyAsync() which supports this scheme.

Method name	Android	iOS
`getInfoAsync`	`file:///`, `content://`, `asset://`, no scheme	`file://`, `ph://`, `assets-library://`
`readAsStringAsync`	`file:///`, `asset://`, SAF URI	`file://`
`writeAsStringAsync`	`file:///`, SAF URI	`file://`
`deleteAsync`	`file:///`, SAF URI	`file://`
`moveAsync`	Source: `file:///`, SAF URI Destination: `file://`	Source: `file://` Destination: `file://`
`copyAsync`	Source: `file:///`, `content://`, `asset://`, SAF URI, no scheme Destination: `file://`	Source: `file://`, `ph://`, `assets-library://` Destination: `file://`
`makeDirectoryAsync`	`file:///`	`file://`
`readDirectoryAsync`	`file:///`	`file://`
`downloadAsync`	Source: `http://`, `https://` Destination: `file:///`	Source: `http://`, `https://` Destination: `file://`
`uploadAsync`	Source: `file:///` Destination: `http://` `https://`	Source: `file://` Destination: `http://` `https://`
`createDownloadResumable`	Source: `http://`, `https://` Destination: `file:///`	Source: `http://`, `https://` Destination: `file://`

On Android no scheme defaults to a bundled resource.

Permissions

Android

The following permissions are added automatically through this library's AndroidManifest.xml.

Android Permission	Description
`READ_EXTERNAL_STORAGE`	Allows an application to read from external storage.
`WRITE_EXTERNAL_STORAGE`	Allows an application to write to external storage.
`INTERNET`	Allows applications to open network sockets.

iOS

No permissions required.