Keycode

ANSI key code parser.

Usage

The keycode module exports a parse() method which accepts an ansi string and return an array of KeyCode.

import { parse } from "https://deno.land/x/cliffy@v0.25.0/keycode/mod.ts";

console.log(
  parse(
    "\x1b[A\x1b[B\x1b[C\x1b[D\x1b[E\x1b[F\x1b[H",
  ),
);Copy

$ deno run --unstable https://deno.land/x/cliffy@v0.25.0/examples/keycode/example.tsCopy

Output:

[
  { name: "up", sequence: "\x1b[A", code: "[A", ctrl: false, meta: false, shift: false },
  { name: "down", sequence: "\x1b[B", code: "[B", ctrl: false, meta: false, shift: false },
  { name: "right", sequence: "\x1b[C", code: "[C", ctrl: false, meta: false, shift: false },
  { name: "left", sequence: "\x1b[D", code: "[D", ctrl: false, meta: false, shift: false },
  { name: "clear", sequence: "\x1b[E", code: "[E", ctrl: false, meta: false, shift: false },
  { name: "end", sequence: "\x1b[F", code: "[F", ctrl: false, meta: false, shift: false },
  { name: "home", sequence: "\x1b[H", code: "[H", ctrl: false, meta: false, shift: false }
]Copy

Example

i

❗ For this example the --unstable flag is required to make Deno.setRaw() available. The module itself does not require the --unstable flag.

import { KeyCode, parse } from "https://deno.land/x/cliffy@v0.25.0/keycode/mod.ts";

async function* keypress(): AsyncGenerator<KeyCode, void> {
  while (true) {
    const data = new Uint8Array(8);

    Deno.setRaw(Deno.stdin.rid, true);
    const nread = await Deno.stdin.read(data);
    Deno.setRaw(Deno.stdin.rid, false);

    if (nread === null) {
      return;
    }

    const keys: Array<KeyCode> = parse(data.subarray(0, nread));

    for (const key of keys) {
      yield key;
    }
  }
}

console.log("Hit ctrl + c to exit.");

for await (const key of keypress()) {
  if (key.ctrl && key.name === "c") {
    console.log("exit");
    break;
  }
  console.log(key);
}Copy

$ deno run --unstable https://deno.land/x/cliffy@v0.25.0/examples/keycode/read_key.tsCopy

← OS signals Keypress →

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