In Bun, the console object is an AsyncIterable that yields lines from stdin.
index.ts
const prompt = "Type something: ";
process.stdout.write(prompt);
for await (const line of console) {
console.log(`You typed: ${line}`);
process.stdout.write(prompt);
}
Running this file starts a never-ending interactive prompt that echoes whatever you type.
bun run index.ts
Type something: hello
You typed: hello
Type something: hello again
You typed: hello again
Bun also exposes stdin as a BunFile, Bun.stdin. Use it to incrementally read large inputs piped into the bun process.
Chunks aren't guaranteed to be split line-by-line.
stdin.ts
for await (const chunk of Bun.stdin.stream()) {
// chunk is Uint8Array
// this converts it to text (assumes UTF-8 encoding)
const chunkText = Buffer.from(chunk).toString();
console.log(`Chunk: ${chunkText}`);
}
Running stdin.ts prints whatever is piped into it.
echo "hello" | bun run stdin.ts
Chunk: hello
See Utils for more utilities.