tinyexec 📟

> A minimal package for executing commands

This package was created to provide a minimal way of interacting with child
processes without having to manually deal with streams, piping, etc.

Installing

``sh
$ npm i -S tinyexec
`

Usage

A process can be spawned and awaited like so:

`ts
import {x} from 'tinyexec';

const result = await x('ls', ['-l']);

// result.stdout - the stdout as a string
// result.stderr - the stderr as a string
// result.exitCode - the process exit code as a number
`

By default, tinyexec does not throw on non‑zero exit codes. Check result.exitCode or pass {throwOnError: true}.

Output is returned exactly as produced; trailing newlines are not trimmed. If you need trimming, do it explicitly:

`ts
const clean = result.stdout.replace(/\r?\n$/, '');
`

You may also iterate over the lines of output via an async loop:

`ts
import {x} from 'tinyexec';

const proc = x('ls', ['-l']);

for await (const line of proc) {
// line will be from stderr/stdout in the order you'd see it in a term
}
`

$3

Options can be passed to have finer control over spawning of the process:

`ts
await x('ls', [], {
timeout: 1000
});
`

The options object can have the following properties:

- signal - an AbortSignal to allow aborting of the execution
- timeout - time in milliseconds at which the process will be forceably killed
- persist - if true, the process will continue after the host exits
- stdin - another Result can be used as the input to this process
- nodeOptions - any valid options to node's underlying spawn function
- throwOnError - if true, non-zero exit codes will throw an error

$3

You can pipe a process to another via the pipe method:

`ts
const proc1 = x('ls', ['-l']);
const proc2 = proc1.pipe('grep', ['.js']);
const result = await proc2;

console.log(result.stdout);
`

pipe takes the same options as a regular execution. For example, you can
pass a timeout to the pipe call:

`ts
proc1.pipe('grep', ['.js'], {
timeout: 2000
});
`

$3

You can kill the process via the kill method:

`ts
const proc = x('ls');

proc.kill();

// or with a signal
proc.kill('SIGHUP');
`

$3

By default, node's available binaries from node_modules will be accessible
in your command.

For example, in a repo which has eslint installed:

`ts
await x('eslint', ['.']);
`

In this example, eslint will come from the locally installed node_modules.

$3

An abort signal can be passed to a process in order to abort it at a later
time. This will result in the process being killed and aborted being set
to true.

`ts
const aborter = new AbortController();
const proc = x('node', ['./foo.mjs'], {
signal: aborter.signal
});

// elsewhere...
aborter.abort();

await proc;

proc.aborted; // true
proc.killed; // true
`

$3

If you need to continue supporting commands as strings (e.g. "command arg0 arg1"),
you can use args-tokenizer,
a lightweight library for parsing shell command strings into an array.

`ts
import {x} from 'tinyexec';
import {tokenizeArgs} from 'args-tokenizer';

const commandString = 'echo "Hello, World!"';
const [command, ...args] = tokenizeArgs(commandString);
const result = await x(command, args);

result.stdout; // Hello, World!
`

API

Calling x(command[, args]) returns an awaitable Result which has the
following API methods and properties available:

$3

Pipes the current command to another. For example:

`ts
x('ls', ['-l'])
.pipe('grep', ['js']);
`

The parameters are as follows:

- command - the command to execute (_without any arguments_)
- args - an array of arguments
- options - options object

$3

The underlying Node.js ChildProcess. tinyexec keeps the surface minimal and does not re‑expose every child_process method/event. Use proc.process for advanced access (streams, events, etc.).

`ts
const proc = x('node', ['./foo.mjs']);

proc.process?.stdout?.on('data', (chunk) => {
// ...
});
proc.process?.once('close', (code) => {
// ...
});
`

$3

Kills the current process with the specified signal. By default, this will
use the SIGTERM signal.

For example:

`ts
const proc = x('ls');

proc.kill();
`

$3

The current process ID. For example:

`ts
const proc = x('ls');

proc.pid; // number
`

$3

Whether the process has been aborted or not (via the signal originally
passed in the options object).

For example:

`ts
const proc = x('ls');

proc.aborted; // bool
`

$3

Whether the process has been killed or not (e.g. via kill() or an abort
signal).

For example:

`ts
const proc = x('ls');

proc.killed; // bool
`

$3

The exit code received when the process completed execution.

For example:

`ts
const proc = x('ls');

proc.exitCode; // number (e.g. 1)
`

Comparison with other libraries

tinyexec aims to provide a lightweight layer on top of Node's own
child_process API.

Some clear benefits compared to other libraries are that tinyexec will be much lighter, have a much
smaller footprint and will have a less abstract interface (less "magic"). It
will also have equal security and cross-platform support to popular
alternatives.

There are various features other libraries include which we are unlikely
to ever implement, as they would prevent us from providing a lightweight layer.

For example, if you'd like write scripts rather than individual commands, and
prefer to use templating, we'd definitely recommend
zx. zx is a much higher level library which
does some of the same work tinyexec does but behind a template string
interface.

Similarly, libraries like execa` will provide helpers for various things
like passing files as input to processes. We opt not to support features like
this since many of them are easy to do yourself (using Node's own APIs).