Read from stdin

Command line tools that work in pipelines read their input from stdin. Try this example with some piped input, for instance: echo "hello" | ende run https://docs.ende.sh/examples/scripts/reading_stdin.ts

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For interactive prompts there are global helpers, no stream handling needed. (They return null when stdin is not a terminal.)

if (Ende.stdin.isTerminal()) {
  const name = prompt("What is your name?");
  console.log(`Hello, ${name}!`);
}

To read all of stdin as a string, collect its readable stream with a Response. This waits until the input ends.

const input = await new Response(Ende.stdin.readable).text();
console.log(`Read ${input.length} characters`);

For line-by-line processing, decode the byte stream into text and split it into lines with the standard library. This processes input as it arrives instead of waiting for the end, which suits large or endless pipelines.

import { TextLineStream } from "jsr:@ende/streams";

async function processLines() {
  const lines = Ende.stdin.readable
    .pipeThrough(new TextDecoderStream())
    .pipeThrough(new TextLineStream());

  for await (const line of lines) {
    console.log(`line: ${line}`);
  }
}

Note that a stream can only be consumed once: pick one of the approaches above per program run.

Run this example locally using the Ende CLI:

ende run https://docs.ende.sh/examples/scripts/reading_stdin.ts

Read from stdin

Additional resources