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Welcome to Bun Installation Quickstart TypeScript TypeScript 6 and 7

Watch Mode Debugging REPL bunfig.toml File Types Module Resolution JSX Auto-install Plugins File System Router

Cookies File I/O Streams Binary Data Archive SQL SQLite S3 Redis Workers Environment Variables Shell Spawn WebView Cron Node-API FFI C Compiler Transpiler CSRF Protection Secrets Console TOML YAML Markdown JSON5 JSONL HTMLRewriter Image Hashing Glob Semver Color Utils Globals Bun APIs Web APIs Node.js Compatibility

Read a file to an ArrayBuffer Read a file to a Buffer Check if a file exists Read a JSON file Get the MIME type of a file Read a file as a ReadableStream Read a file as a string Read a file to a Uint8Array Watch a directory for changes

File SystemRead file

Watch a directory for changes

Bun implements the node:fs module, including the fs.watch function for listening for file system changes.

Read a file to a Uint8Array

The Bun.file() function accepts a path and returns a BunFile instance. BunFile extends Blob , so you can read the file lazily in a variety of formats.

Append content to a file

Bun implements the node:fs module, which includes the fs.appendFile and fs.appendFileSync functions for appending content to files.