The Path Module in Node.js

1. Windows vs POSIX

The default behavior of path depends on the operating system. For consistent results:

• path.win32: Windows-specific methods.
• path.posix: POSIX-specific methods.

2. Basic Methods

• path.basename(path[, suffix]): Returns the last portion of a path (file name).
• path.dirname(path): Returns the directory name.
• path.extname(path): Returns the file extension.

path.basename('/foo/bar/file.txt'); // 'file.txt'
path.dirname('/foo/bar/file.txt');  // '/foo/bar'
path.extname('index.html');         // '.html'

3. Constructing and Parsing Paths

• path.format(pathObject): Builds a path string from an object.
• path.parse(path): Breaks a path into root, dir, base, name, and ext.

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

4. Joining and Normalizing

• path.join([...paths]): Joins path segments.
• path.normalize(path): Normalizes a path (resolves .. and .).
• path.resolve([...paths]): Resolves segments into an absolute path.

path.join('/foo', 'bar', 'baz'); // '/foo/bar/baz'
path.normalize('/foo/bar//baz/..'); // '/foo/bar'
path.resolve('www', 'static/img');  // '/home/user/www/static/img'

5. Path Checks

• path.isAbsolute(path): Checks if a path is absolute.
• path.relative(from, to): Returns the relative path between two paths.

path.isAbsolute('/foo/bar'); // true
path.relative('/data/test', '/data/impl'); // '../impl'

6. OS-Specific Constants

• path.delimiter: Path delimiter in environment variables (: on POSIX, ; on Windows).
• path.sep: Path segment separator (/ on POSIX, \ on Windows).

7. Windows-Specific Features

• path.toNamespacedPath(path): Converts to a namespace-prefixed path (Windows only).
• path.win32: Windows-specific implementation of path methods.

Conclusion

The path module in Node.js provides powerful tools for managing file and directory paths across different operating systems. With its methods, developers can parse, construct, normalize, and validate paths, ensuring cross-platform compatibility in applications.