Append data to a file.
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> Append data to a file.
To use as a general utility, install the CLI package globally
``bash`
npm install -g @stdlib/fs-append-file-cli
`text
Usage: append-file [options]
Options:
-h, --help Print this message.
-V, --version Print the package version.
--enc, --encoding encoding Encoding. Default: 'utf8'.
--flag flag Flag. Default: 'a'.
--mode mode Mode. Default: 0o666.
`
- Relative output file paths are resolved relative to the current working directory.
- Errors are written to stderr.stdin
- File contents should be provided over as part of a [standard stream][standard-stream] pipeline.
`bash`
$ printf 'beep boop\n' | append-file ./examples/fixtures/file.txt
- [@stdlib/fs-append-file][@stdlib/fs-append-file]: append data to a file.
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[cli-section]: https://github.com/stdlib-js/fs-append-file#cli
[cli-url]: https://github.com/stdlib-js/fs-append-file/tree/cli
[@stdlib/fs-append-file]: https://www.npmjs.com/package/@stdlib/fs-append-file
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/fs-append-file/tree/deno
[deno-readme]: https://github.com/stdlib-js/fs-append-file/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/fs-append-file/tree/umd
[umd-readme]: https://github.com/stdlib-js/fs-append-file/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/fs-append-file/tree/esm
[esm-readme]: https://github.com/stdlib-js/fs-append-file/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/fs-append-file/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-append-file/main/LICENSE
[node-fs]: https://nodejs.org/api/fs.html
[@stdlib/buffer/ctor]: https://www.npmjs.com/package/@stdlib/buffer-ctor
[standard-stream]: https://en.wikipedia.org/wiki/Pipeline_%28Unix%29