Deno.stdin - Deno - Deno Docs

variable Deno.stdin

A reference to stdin which can be used to read directly from stdin.

It implements the Deno specific Reader, ReaderSync, and Closer interfaces as well as provides a ReadableStream interface.

Reading chunks from the readable stream

const decoder = new TextDecoder();
for await (const chunk of Deno.stdin.readable) {
  const text = decoder.decode(chunk);
  // do something with the text
}

Properties

readonly



readable: ReadableStream<Uint8Array>

A readable stream interface to stdin.

Methods



read(p: Uint8Array): Promise<number | null>

Read the incoming data from stdin into an array buffer (p).

Resolves to either the number of bytes read during the operation or EOF (null) if there was nothing more to read.

It is possible for a read to successfully return with 0 bytes. This does not indicate EOF.

It is not guaranteed that the full buffer will be read in a single call.

// If the text "hello world" is piped into the script:
const buf = new Uint8Array(100);
const numberOfBytesRead = await Deno.stdin.read(buf); // 11 bytes
const text = new TextDecoder().decode(buf);  // "hello world"



readSync(p: Uint8Array): number | null

Synchronously read from the incoming data from stdin into an array buffer (p).

Returns either the number of bytes read during the operation or EOF (null) if there was nothing more to read.

It is possible for a read to successfully return with 0 bytes. This does not indicate EOF.

It is not guaranteed that the full buffer will be read in a single call.

// If the text "hello world" is piped into the script:
const buf = new Uint8Array(100);
const numberOfBytesRead = Deno.stdin.readSync(buf); // 11 bytes
const text = new TextDecoder().decode(buf);  // "hello world"



close(): void

Closes stdin, freeing the resource.

Deno.stdin.close();



setRaw(mode: boolean,
options?: SetRawOptions,
): void

Set TTY to be under raw mode or not. In raw mode, characters are read and returned as is, without being processed. All special processing of characters by the terminal is disabled, including echoing input characters. Reading from a TTY device in raw mode is faster than reading from a TTY device in canonical mode.

Deno.stdin.setRaw(true, { cbreak: true });



isTerminal(): boolean

Checks if stdin is a TTY (terminal).

// This example is system and context specific
Deno.stdin.isTerminal(); // true