nodejs/doc/api/path.md

Path

Stability: 2 - Stable

The path module provides utilities for working with file and directory paths. It can be accessed using:

const path = require('path');

Windows vs. POSIX

The default operation of the path module varies based on the operating system on which a Node.js application is running. Specifically, when running on a Windows operating system, the path module will assume that Windows-style paths are being used.

For example, using the path.basename() function with the Windows file path C:\temp\myfile.html, will yield different results when running on POSIX than when run on Windows:

On POSIX:

path.basename('C:\\temp\\myfile.html');
  // returns 'C:\temp\myfile.html'

On Windows:

path.basename('C:\\temp\\myfile.html');
  // returns 'myfile.html'

To achieve consistent results when working with Windows file paths on any operating system, use path.win32:

On POSIX and Windows:

path.win32.basename('C:\\temp\\myfile.html');
  // returns 'myfile.html'

To achieve consistent results when working with POSIX file paths on any operating system, use path.posix:

On POSIX and Windows:

path.posix.basename('/tmp/myfile.html');
  // returns 'myfile.html'

path.basename(path[, ext])

• path {String}
• ext {String} An optional file extension
• Returns: {String}

The path.basename() methods returns the last portion of a path, similar to the Unix basename command.

For example:

path.basename('/foo/bar/baz/asdf/quux.html')
  // returns 'quux.html'

path.basename('/foo/bar/baz/asdf/quux.html', '.html')
  // returns 'quux'

A TypeError is thrown if path is not a string or if ext is given and is not a string.

path.delimiter

• {String}

Provides the platform-specific path delimiter:

• ; for Windows
• : for POSIX

For example, on POSIX:

console.log(process.env.PATH)
// '/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin'

process.env.PATH.split(path.delimiter)
// returns ['/usr/bin', '/bin', '/usr/sbin', '/sbin', '/usr/local/bin']

On Windows:

console.log(process.env.PATH)
// 'C:\Windows\system32;C:\Windows;C:\Program Files\node\'

process.env.PATH.split(path.delimiter)
// returns ['C:\\Windows\\system32', 'C:\\Windows', 'C:\\Program Files\\node\\']

path.dirname(path)

• path {String}
• Returns: {String}

The path.dirname() method returns the directory name of a path, similar to the Unix dirname command.

For example:

path.dirname('/foo/bar/baz/asdf/quux')
// returns '/foo/bar/baz/asdf'

A TypeError is thrown if path is not a string.

path.extname(path)

• path {String}
• Returns: {String}

The path.extname() method returns the extension of the path, from the last occurrence of the . (period) character to end of string in the last portion of the path. If there is no . in the last portion of the path, or if the first character of the basename of path (see path.basename()) is ., then an empty string is returned.

For example:

path.extname('index.html')
// returns '.html'

path.extname('index.coffee.md')
// returns '.md'

path.extname('index.')
// returns '.'

path.extname('index')
// returns ''

path.extname('.index')
// returns ''

A TypeError is thrown if path is not a string.

path.format(pathObject)

• pathObject {Object}
  • dir {String}
  • root {String}
  • base {String}
  • name {String}
  • ext {String}
• Returns: {String}

The path.format() method returns a path string from an object. This is the opposite of path.parse().

The following process is used when constructing the path string:

• output is set to an empty string.
• If pathObject.dir is specified, pathObject.dir is appended to output followed by the value of path.sep;
• Otherwise, if pathObject.root is specified, pathObject.root is appended to output.
• If pathObject.base is specified, pathObject.base is appended to output;
• Otherwise:
  • If pathObject.name is specified, pathObject.name is appended to output
  • If pathObject.ext is specified, pathObject.ext is appended to output.
• Return output

For example, on POSIX:

// If `dir` and `base` are provided,
// `${dir}${path.sep}${base}`
// will be returned.
path.format({
  dir: '/home/user/dir',
  base: 'file.txt'
});
// returns '/home/user/dir/file.txt'

// `root` will be used if `dir` is not specified.
// If only `root` is provided or `dir` is equal to `root` then the
// platform separator will not be included.
path.format({
  root: '/',
  base: 'file.txt'
});
// returns '/file.txt'

// `name` + `ext` will be used if `base` is not specified.
path.format({
  root: '/',
  name: 'file',
  ext: '.txt'
});
// returns '/file.txt'

// `base` will be returned if `dir` or `root` are not provided.
path.format({
  base: 'file.txt'
});
// returns 'file.txt'

On Windows:

path.format({
    root : "C:\\",
    dir : "C:\\path\\dir",
    base : "file.txt",
    ext : ".txt",
    name : "file"
});
// returns 'C:\\path\\dir\\file.txt'

path.isAbsolute(path)

• path {String}
• Returns: {Boolean}

The path.isAbsolute() method determines if path is an absolute path.

If the given path is a zero-length string, false will be returned.

For example on POSIX:

path.isAbsolute('/foo/bar') // true
path.isAbsolute('/baz/..')  // true
path.isAbsolute('qux/')     // false
path.isAbsolute('.')        // false

On Windows:

path.isAbsolute('//server')    // true
path.isAbsolute('\\\\server')  // true
path.isAbsolute('C:/foo/..')   // true
path.isAbsolute('C:\\foo\\..') // true
path.isAbsolute('bar\\baz')    // false
path.isAbsolute('bar/baz')     // false
path.isAbsolute('.')           // false

A TypeError is thrown if path is not a string.

path.join([...paths])

• ...paths {String} A sequence of path segments
• Returns: {String}

The path.join() method joins all given path segments together using the platform specific separator as a delimiter, then normalizes the resulting path.

Zero-length path segments are ignored. If the joined path string is a zero-length string then '.' will be returned, representing the current working directory.

For example:

path.join('/foo', 'bar', 'baz/asdf', 'quux', '..')
// returns '/foo/bar/baz/asdf'

path.join('foo', {}, 'bar')
// throws TypeError: Arguments to path.join must be strings

A TypeError is thrown if any of the path segments is not a string.

path.normalize(path)

• path {String}
• Returns: {String}

The path.normalize() method normalizes the given path, resolving '..' and '.' segments.

When multiple, sequential path segment separation characters are found (e.g. / on POSIX and \ on Windows), they are replaced by a single instance of the platform specific path segment separator. Trailing separators are preserved.

If the path is a zero-length string, '.' is returned, representing the current working directory.

For example on POSIX:

path.normalize('/foo/bar//baz/asdf/quux/..')
// returns '/foo/bar/baz/asdf'

On Windows:

path.normalize('C:\\temp\\\\foo\\bar\\..\\');
// returns 'C:\\temp\\foo\\'

A TypeError is thrown if path is not a string.

path.parse(path)

• path {String}
• Returns: {Object}

The path.parse() method returns an object whose properties represent significant elements of the path.

The returned object will have the following properties:

• root {String}
• dir {String}
• base {String}
• ext {String}
• name {String}

For example on POSIX:

path.parse('/home/user/dir/file.txt')
// returns
// {
//    root : "/",
//    dir : "/home/user/dir",
//    base : "file.txt",
//    ext : ".txt",
//    name : "file"
// }

┌─────────────────────┬────────────┐
│          dir        │    base    │
├──────┬              ├──────┬─────┤
│ root │              │ name │ ext │
"  /    home/user/dir / file  .txt "
└──────┴──────────────┴──────┴─────┘
(all spaces in the "" line should be ignored -- they are purely for formatting)

On Windows:

path.parse('C:\\path\\dir\\file.txt')
// returns
// {
//    root : "C:\\",
//    dir : "C:\\path\\dir",
//    base : "file.txt",
//    ext : ".txt",
//    name : "file"
// }

┌─────────────────────┬────────────┐
│          dir        │    base    │
├──────┬              ├──────┬─────┤
│ root │              │ name │ ext │
" C:\      path\dir   \ file  .txt "
└──────┴──────────────┴──────┴─────┘
(all spaces in the "" line should be ignored -- they are purely for formatting)

A TypeError is thrown if path is not a string.

path.posix

• {Object}

The path.posix property provides access to POSIX specific implementations of the path methods.

path.relative(from, to)

• from {String}
• to {String}
• Returns: {String}

The path.relative() method returns the relative path from from to to. If from and to each resolve to the same path (after calling path.resolve() on each), a zero-length string is returned.

If a zero-length string is passed as from or to, the current working directory will be used instead of the zero-length strings.

For example on POSIX:

path.relative('/data/orandea/test/aaa', '/data/orandea/impl/bbb')
// returns '../../impl/bbb'

On Windows:

path.relative('C:\\orandea\\test\\aaa', 'C:\\orandea\\impl\\bbb')
// returns '..\\..\\impl\\bbb'

A TypeError is thrown if neither from nor to is a string.

path.resolve([...paths])

• ...paths {String} A sequence of paths or path segments
• Returns: {String}

The path.resolve() method resolves a sequence of paths or path segments into an absolute path.

The given sequence of paths is processed from right to left, with each subsequent path prepended until an absolute path is constructed. For instance, given the sequence of path segments: /foo, /bar, baz, calling path.resolve('/foo', '/bar', 'baz') would return /bar/baz.

If after processing all given path segments an absolute path has not yet been generated, the current working directory is used.

The resulting path is normalized and trailing slashes are removed unless the path is resolved to the root directory.

Zero-length path segments are ignored.

If no path segments are passed, path.resolve() will return the absolute path of the current working directory.

For example:

path.resolve('/foo/bar', './baz')
// returns '/foo/bar/baz'

path.resolve('/foo/bar', '/tmp/file/')
// returns '/tmp/file'

path.resolve('wwwroot', 'static_files/png/', '../gif/image.gif')
// if the current working directory is /home/myself/node,
// this returns '/home/myself/node/wwwroot/static_files/gif/image.gif'

A TypeError is thrown if any of the arguments is not a string.

path.sep

• {String}

Provides the platform-specific path segment separator:

• \ on Windows
• / on POSIX

For example on POSIX:

'foo/bar/baz'.split(path.sep)
// returns ['foo', 'bar', 'baz']

On Windows:

'foo\\bar\\baz'.split(path.sep)
// returns ['foo', 'bar', 'baz']

path.win32

• {Object}

The path.win32 property provides access to Windows-specific implementations of the path methods.

Note: On Windows, both the forward slash (/) and backward slash (\) characters are accepted as path delimiters; however, only the backward slash (\) will be used in return values.