lazy-command.js

Rust-like Command wrapper over node.js child_process

It provides simple & unified builder for Node.js child_process

Overview

Defaults

• Inherits parent's environment.
• Inherits parent's current directory.

Execution methods

• spawn - Equal to child_process.spawn or child_process.spawnSync.
• exec - Equal to child_process.exec or child_process.execSync.
• execFile - Equal to child_process.execFile or child_process.execFileSync.
• output - Equal to child_process.spawnSync but returns only status, stdout and stderr.
• status - Equal to child_process.execSync but returns only status.

Sync vs Async

By default Command executes asynchronously.

In order to configure command for synchronous execution you need to call method sync

For example to perform exec synchronously:

const status = require('lazy-command.js')('git -status').sync().exec()

For asynchronous version you need to omit sync.

const status = require('lazy-command.js')('git -status').exec()

Async callback

Setting of callback is optional but method callback can be used to provide it.

The signature of callback is the same as for any corresponding child_process functions.

For example:

const cb = (err, stdout, stderr) => {
    console.log("Err=%s | stdout=%s | stderr=%s", err, stdout, stderr);
};
const status = require('lazy-command.js')('git -status').callback(cb).exec()

Examples

Collect all output of command

const Command = require('lazy-command.js');

const result = Command("git -status").encoding('utf-8').output();

console.log("status=% | stdout=%s | stderr=%s",
            result.status, result.stdout, result.stderr);

Just get status code

const Command = require('lazy-command.js');

const result = Command("git -status").stdio_ignore().status();;

console.log("Status=%s", result);

Let's make lot of configuration

const Command = require('lazy-command.js');

const result = Command("git").stdio_ignore()
                             .arg("-status")
                             .current_dir("lib/");
                             .timeout(1000)
                             .status();;

console.log("Status=%s", result);