# Filesystem > Filesystem APIs.
## Usage ```javascript var fs = require( '@stdlib/fs' ); ``` #### fs Namespace for filesystem APIs. ```javascript var f = fs; // returns {...} ```
- [`close( fd, clbk )`][@stdlib/fs/close]: close a file descriptor. - [`exists( path, clbk )`][@stdlib/fs/exists]: test whether a path exists on the filesystem. - [`open( path[, flags[, mode]], clbk )`][@stdlib/fs/open]: open a file. - [`readDir( path, clbk )`][@stdlib/fs/read-dir]: read the contents of a directory. - [`readFileList( filepaths[, options], clbk )`][@stdlib/fs/read-file-list]: read the entire contents of each file in a file list. - [`readFile( file[, options], clbk )`][@stdlib/fs/read-file]: read the entire contents of a file. - [`readJSON( file[, options], clbk )`][@stdlib/fs/read-json]: read a file as JSON. - [`readWASM( file[, options], clbk )`][@stdlib/fs/read-wasm]: read a file as WebAssembly. - [`rename( oldPath, newPath, clbk )`][@stdlib/fs/rename]: rename a file. - [`resolveParentPathBy( path[, options], predicate, clbk )`][@stdlib/fs/resolve-parent-path-by]: resolve a path according to a predicate function by walking parent directories. - [`resolveParentPath( path[, options], clbk )`][@stdlib/fs/resolve-parent-path]: resolve a path by walking parent directories. - [`unlink( path, clbk )`][@stdlib/fs/unlink]: remove a directory entry. - [`writeFile( file, data[, options], clbk )`][@stdlib/fs/write-file]: write data to a file.
## Examples ```javascript var objectKeys = require( '@stdlib/utils/keys' ); var fs = require( '@stdlib/fs' ); console.log( objectKeys( fs ) ); ```
[@stdlib/fs/close]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/close [@stdlib/fs/exists]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/exists [@stdlib/fs/open]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/open [@stdlib/fs/read-dir]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/read-dir [@stdlib/fs/read-file-list]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/read-file-list [@stdlib/fs/read-file]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/read-file [@stdlib/fs/read-json]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/read-json [@stdlib/fs/read-wasm]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/read-wasm [@stdlib/fs/rename]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/rename [@stdlib/fs/resolve-parent-path-by]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/resolve-parent-path-by [@stdlib/fs/resolve-parent-path]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/resolve-parent-path [@stdlib/fs/unlink]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/unlink [@stdlib/fs/write-file]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/fs/write-file