Deno.stderr - Deno

variable Deno.stderr

A reference to stderr which can be used to write directly to stderr. It implements the Deno specific Writer, WriterSync, and Closer interfaces as well as provides a WritableStream interface.

These are low level constructs, and the console interface is a more straight forward way to interact with stdout and stderr.

Properties

readonly



writable: WritableStream<Uint8Array>

A writable stream interface to stderr.

Methods



write(p: Uint8Array): Promise<number>

Write the contents of the array buffer (p) to stderr.

Resolves to the number of bytes written.

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

const encoder = new TextEncoder();
const data = encoder.encode("Hello world");
const bytesWritten = await Deno.stderr.write(data); // 11



writeSync(p: Uint8Array): number

Synchronously write the contents of the array buffer (p) to stderr.

Returns the number of bytes written.

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

const encoder = new TextEncoder();
const data = encoder.encode("Hello world");
const bytesWritten = Deno.stderr.writeSync(data); // 11



close(): void

Closes stderr, freeing the resource.

Deno.stderr.close();



isTerminal(): boolean

Checks if stderr is a TTY (terminal).

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