nodejs/doc/api/path.markdown

Path

Stability: 2 - Stable

This module contains utilities for handling and transforming file paths. Almost all these methods perform only string transformations. The file system is not consulted to check whether paths are valid.

Use require('path') to use this module. The following methods are provided:

path.normalize(p)

Normalize a string path, taking care of '..' and '.' parts.

When multiple slashes are found, they're replaced by a single one; when the path contains a trailing slash, it is preserved. On Windows backslashes are used.

Example:

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

Note: If the path string passed as argument is a zero-length string then '.' will be returned, which represents the current working directory.

path.join([path1][, path2][, ...])

Join all arguments together and normalize the resulting path.

Arguments must be strings. In v0.8, non-string arguments were silently ignored. In v0.10 and up, an exception is thrown.

Example:

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

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

Note: If the arguments to join have zero-length strings, unlike other path module functions, they will be ignored. If the joined path string is a zero-length string then '.' will be returned, which represents the current working directory.

path.resolve([from ...], to)

Resolves to to an absolute path.

If to isn't already absolute from arguments are prepended in right to left order, until an absolute path is found. If after using all from paths still no absolute path is found, the current working directory is used as well. The resulting path is normalized, and trailing slashes are removed unless the path gets resolved to the root directory. Non-string from arguments are ignored.

Another way to think of it is as a sequence of cd commands in a shell.

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

Is similar to:

cd foo/bar
cd /tmp/file/
cd ..
cd a/../subfile
pwd

The difference is that the different paths don't need to exist and may also be files.

Examples:

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 currently in /home/myself/node, it returns
'/home/myself/node/wwwroot/static_files/gif/image.gif'

Note: If the arguments to resolve have zero-length strings then the current working directory will be used instead of them.

path.isAbsolute(path)

Determines whether path is an absolute path. An absolute path will always resolve to the same location, regardless of the working directory.

Posix examples:

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

Windows examples:

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

Note: If the path string passed as parameter is a zero-length string, unlike other path module functions, it will be used as-is and false will be returned.

path.relative(from, to)

Solve the relative path from from to to.

At times we have two absolute paths, and we need to derive the relative path from one to the other. This is actually the reverse transform of path.resolve, which means we see that:

path.resolve(from, path.relative(from, to)) == path.resolve(to)

Examples:

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

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

Note: If the arguments to relative have zero-length strings then the current working directory will be used instead of the zero-length strings. If both the paths are the same then a zero-length string will be returned.

path.dirname(p)

Return the directory name of a path. Similar to the Unix dirname command.

Example:

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

path.basename(p[, ext])

Return the last portion of a path. Similar to the Unix basename command.

Example:

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

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

path.extname(p)

Return the extension of the path, from the last '.' to end of string in the last portion of the path. If there is no '.' in the last portion of the path or the first character of it is '.', then it returns an empty string. Examples:

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
''

path.sep

The platform-specific file separator. '\\' or '/'.

An example on *nix:

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

An example on Windows:

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

path.delimiter

The platform-specific path delimiter, ; or ':'.

An example on *nix:

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']

An example 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.parse(pathString)

Returns an object from a path string.

An example on *nix:

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

An example on Windows:

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

path.format(pathObject)

Returns a path string from an object, the opposite of path.parse above.

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

path.posix

Provide access to aforementioned path methods but always interact in a posix compatible way.

path.win32

Provide access to aforementioned path methods but always interact in a win32 compatible way.