Subprocesses

import { Command } from "runtime:system";

const { success, code, stdout, stderr } = await new Command("git", {
  args: ["rev-parse", "HEAD"],
}).output();

const sha = new TextDecoder().decode(stdout).trim();

import { Command } from "runtime:system";

const child = await new Command("ffmpeg", {
  args: ["-i", "pipe:0", "-f", "mp3", "pipe:1"],
  stdin: request.body,                     // string, bytes, Blob, Response, stream
  stderr: "inherit",                       // straight to this process's stderr
}).spawn();

return new Response(child.stdout);

const child = await new Command("cat", { stdin: "piped" }).spawn();
const writer = child.stdin.getWriter();
await writer.write(new TextEncoder().encode("a line\n"));
await writer.close();                      // the child's EOF

for await (const chunk of child.stdout.pipeThrough(new TextDecoderStream())) {
  console.log(chunk);
}

import { Command } from "runtime:system";
import { env } from "runtime:process";

// Explicit: the child sees these two variables and nothing else.
await new Command("./deploy.sh", {
  env: { PATH: env.PATH, API_TOKEN: env.API_TOKEN },
}).output();

// Or inherit the lot — needs the Env capability as well as Run.
await new Command("git", { args: ["status"], inheritEnv: true }).output();

const child = await new Command("sleep", { args: ["300"] }).spawn();
await child.kill("SIGTERM");
const { signal } = await child.status;     // "SIGTERM"

// Rejects with a TimeoutError; the child is killed with killSignal.
await new Command("slow-tool", { timeout: 30_000, killSignal: "SIGKILL" }).output();

// Or share a signal with the rest of the request.
await new Command("slow-tool", { signal: request.signal }).output();