The fs module of the JavaScript API

const fs = require('fs')

The implementation tries to follow the CommonJS Filesystem/A/0  specification where possible.

Working Directory

The directory functions below shouldn’t use the current working directory of the server like . or ./test. You will not be able to tell whether the environment the server is running in will permit directory listing, reading or writing of files.

You should either base your directories with getTempPath(), or as a Foxx service use the module.context.basePath.

Single File Directory Manipulation

exists

checks if a file of any type or directory exists fs.exists(path)

Returns true if a file (of any type) or a directory exists at a given path. If the file is a broken symbolic link, returns false.

isFile

tests if path is a file fs.isFile(path)

Returns true if the path points to a file.

isDirectory

tests if path is a directory fs.isDirectory(path)

Returns true if the path points to a directory.

size

gets the size of a file fs.size(path)

Returns the size of the file specified by path.

mtime

gets the last modification time of a file fs.mtime(filename)

Returns the last modification date of the specified file. The date is returned as a Unix timestamp (number of seconds elapsed since January 1 1970).

pathSeparator

fs.pathSeparator

If you want to combine two paths you can use fs.pathSeparator instead of / or \\.

join

fs.join(path, filename)

The function returns the combination of the path and filename, e.g. fs.join('folder', 'file.ext') would return folder/file.ext.

getTempFile

returns the name for a (new) temporary file fs.getTempFile(directory, createFile)

Returns the name for a new temporary file in directory directory. If createFile is true, an empty file will be created so no other process can create a file of the same name.

Note: The directory directory must exist.

getTempPath

returns the temporary directory fs.getTempPath()

Returns the absolute path of the temporary directory

makeAbsolute

makes a given path absolute fs.makeAbsolute(path)

Returns the given string if it is an absolute path, otherwise an absolute path to the same location is returned.

chmod

sets file permissions of specified files fs.chmod(path, mode)

where mode is a string with a leading zero matching the OCTAL-MODE as explained in *nix man chmod.

Returns true on success.

list

returns the directory listing fs.list(path)

The functions returns the names of all the files in a directory, in lexically sorted order. Throws an exception if the directory cannot be traversed (or path is not a directory).

Note: this means that list(“x”) of a directory containing “a” and “b” would return [“a”, “b”], not [“x/a”, “x/b”].

listTree

returns the directory tree fs.listTree(path)

The function returns an array that starts with the given path, and all of the paths relative to the given path, discovered by a depth first traversal of every directory in any visited directory, reporting but not traversing symbolic links to directories. The first path is always "", the path relative to itself.

makeDirectory

creates a directory fs.makeDirectory(path)

Creates the directory specified by path.

makeDirectoryRecursive

creates a directory fs.makeDirectoryRecursive(path)

Creates the directory hierarchy specified by path.

remove

removes a file fs.remove(filename)

Removes the file filename at the given path. Throws an exception if the path corresponds to anything that is not a file or a symbolic link. If “path” refers to a symbolic link, removes the symbolic link.

removeDirectory

removes an empty directory fs.removeDirectory(path)

Removes a directory if it is empty. Throws an exception if the path is not an empty directory.

removeDirectoryRecursive

removes a directory fs.removeDirectoryRecursive(path)

Removes a directory with all subelements. Throws an exception if the path is not a directory.

File IO

read

reads in a file fs.read(filename)

Reads in a file and returns the content as string. Please note that the file content must be encoded in UTF-8.

read64

reads in a file as base64 fs.read64(filename)

Reads in a file and returns the content as string. The file content is Base64 encoded.

readBuffer

reads in a file fs.readBuffer(filename)

Reads in a file and returns its content in a Buffer object.

readFileSync

fs.readFileSync(filename, encoding)

Reads the contents of the file specified in filename. If encoding is specified, the file contents will be returned as a string. Supported encodings are:

• utf8 or utf-8
• ascii
• base64
• ucs2 or ucs-2
• utf16le or utf16be
• hex

If no encoding is specified, the file contents will be returned in a Buffer object.

write

fs.write(filename, content)

Writes the content into a file. Content can be a string or a Buffer object. If the file already exists, it is truncated.

writeFileSync

fs.writeFileSync(filename, content)

This is an alias for fs.write(filename, content).

append

fs.append(filename, content)

Writes the content into a file. Content can be a string or a Buffer object. If the file already exists, the content is appended at the end.

Recursive Manipulation

copyRecursive

copies a directory structure fs.copyRecursive(source, destination)

Copies source to destination. Exceptions will be thrown on:

• Failure to copy the file
• specifying a directory for destination when source is a file
• specifying a directory as source and destination

CopyFile

copies a file into a target file fs.copyFile(source, destination)

Copies source to destination. If Destination is a directory, a file of the same name will be created in that directory, else the copy will get the specified filename.

linkFile

creates a symbolic link from a target in the place of linkpath. fs.linkFile(target, linkpath)

In linkpath a symbolic link to target will be created.

move

renames a file fs.move(source, destination)

Moves source to destination. Failure to move the file, or specifying a directory for destination when source is a file will throw an exception. Likewise, specifying a directory as source and destination will fail.

ZIP

unzipFile

unzips a file fs.unzipFile(filename, outpath, skipPaths, overwrite, password)

Unzips the zip file specified by filename into the path specified by outpath. Overwrites any existing target files if overwrite is set to true.

Returns true if the file was unzipped successfully.

zipFile

zips a file fs.zipFile(filename, chdir, files, password)

Stores the files specified by files in the zip file filename. If the file filename already exists, an error is thrown. The list of input files files must be given as a list of absolute filenames. If chdir is not empty, the chdir prefix will be stripped from the filename in the zip file, so when it is unzipped filenames will be relative. Specifying a password is optional.

Returns true if the file was zipped successfully.