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Module

x/deno/cli/tsc/dts/lib.deno.ns.d.ts>Deno.Command

A modern runtime for JavaScript and TypeScript.
denoland/deno
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class Deno.Command
import { Deno } from "https://deno.land/x/deno@v1.32.3/cli/tsc/dts/lib.deno.ns.d.ts";
const { Command } = Deno;

Create a child process.

If any stdio options are not set to "piped", accessing the corresponding field on the Command or its CommandOutput will throw a TypeError.

If stdin is set to "piped", the stdin WritableStream needs to be closed manually.

Examples

Spawn a subprocess and pipe the output to a file

const command = new Deno.Command(Deno.execPath(), {
  args: [
    "eval",
    "console.log('Hello World')",
  ],
  stdin: "piped",
});
const child = command.spawn();

// open a file and pipe the subprocess output to it.
child.stdout.pipeTo(Deno.openSync("output").writable);

// manually close stdin
child.stdin.close();
const status = await child.status;

Spawn a subprocess and collect its output

const command = new Deno.Command(Deno.execPath(), {
  args: [
    "eval",
    "console.log('hello'); console.error('world')",
  ],
});
const { code, stdout, stderr } = await command.output();
console.assert(code === 0);
console.assert("hello\n" === new TextDecoder().decode(stdout));
console.assert("world\n" === new TextDecoder().decode(stderr));

Spawn a subprocess and collect its output synchronously

const command = new Deno.Command(Deno.execPath(), {
  args: [
    "eval",
    "console.log('hello'); console.error('world')",
  ],
});
const { code, stdout, stderr } = command.outputSync();
console.assert(code === 0);
console.assert("hello\n" === new TextDecoder().decode(stdout));
console.assert("world\n" === new TextDecoder().decode(stderr));

Constructors

new
Command(command: string | URL, options?: CommandOptions)

Methods

output(): Promise<CommandOutput>

Executes the Deno.Command, waiting for it to finish and collecting all of its output. If spawn() was called, calling this function will collect the remaining output.

Will throw an error if stdin: "piped" is set.

If options stdout or stderr are not set to "piped", accessing the corresponding field on Deno.CommandOutput will throw a TypeError.

outputSync(): CommandOutput

Synchronously executes the Deno.Command, waiting for it to finish and collecting all of its output.

Will throw an error if stdin: "piped" is set.

If options stdout or stderr are not set to "piped", accessing the corresponding field on Deno.CommandOutput will throw a TypeError.

spawn(): ChildProcess

Spawns a streamable subprocess, allowing to use the other methods.