# nanoprocess > Maintain a child process as a nanoresource Latest version **0.8.5** (published 2020-03-17) · MIT license · 0 weekly downloads ## Install ```sh npm install nanoprocess pnpm add nanoprocess yarn add nanoprocess bun add nanoprocess ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support; pre 1.0. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 0.8.5 | | Published | 2020-03-17 | | First published | 2019-10-27 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 10 | | Unpacked size | 25.4 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 6 | | Author | Joseph Werle | | Maintainers | werle | | Keywords | nano, resource, child, process | ## Links - npm: https://www.npmjs.com/package/nanoprocess - Repository: https://github.com/little-core-labs/nanoprocess - Homepage: https://github.com/little-core-labs/nanoprocess#readme - Issues: https://github.com/little-core-labs/nanoprocess/issues - npm.io page: https://npm.io/package/nanoprocess ## Dependencies (10) - [once](https://npm.io/package/once.md) ^1.4.0 - [batch](https://npm.io/package/batch.md) ^0.6.1 - [fkill](https://npm.io/package/fkill.md) ^7.0.0 - [pidtree](https://npm.io/package/pidtree.md) ^0.3.0 - [pidusage](https://npm.io/package/pidusage.md) ^2.0.17 - [is-running](https://npm.io/package/is-running.md) ^2.1.0 - [nanoassert](https://npm.io/package/nanoassert.md) ^2.0.0 - [cross-spawn](https://npm.io/package/cross-spawn.md) ^7.0.1 - [find-process](https://npm.io/package/find-process.md) ^1.4.2 - [nanoresource](https://npm.io/package/nanoresource.md) ^1.2.0 ## Alternatives - [@sindresorhus/slugify](https://npm.io/package/@sindresorhus/slugify.md) — 3.7M weekly downloads - [solid-js](https://npm.io/package/solid-js.md) — 2.7M weekly downloads - [expo-glass-effect](https://npm.io/package/expo-glass-effect.md) — 2.5M weekly downloads - [nanoassert](https://npm.io/package/nanoassert.md) — 780.8K weekly downloads - [@ffmpeg/ffmpeg](https://npm.io/package/@ffmpeg/ffmpeg.md) — 529.5K weekly downloads ## Recent versions - 0.8.5 (latest) — 2020-03-17 - 0.8.4 — 2020-03-16 - 0.8.3 — 2020-03-16 - 0.8.2 — 2020-03-16 - 0.8.1 — 2019-12-04 - 0.8.0 — 2019-11-28 - 0.7.0 — 2019-10-31 - 0.6.0 — 2019-10-31 - 0.5.0 — 2019-10-31 - 0.4.1 — 2019-10-31 - 0.4.0 — 2019-10-31 - 0.3.0 — 2019-10-31 - 0.2.2 — 2019-10-28 - 0.2.1 — 2019-10-27 - 0.2.0 — 2019-10-27 - … 2 more at https://npm.io/package/nanoprocess/versions ## README nanoprocess =========== > Maintain a child process as a [nanoresource][nanoresource] ## Installation ```sh $ npm install nanoprocess ``` ## Status > **Stable** > [![Actions Status](https://github.com/little-core-labs/nanoprocess/workflows/Node%20CI/badge.svg)](https://github.com/little-core-labs/nanoprocess/actions) ## Usage ```js const nanoprocess = require('nanoprocess') // spawn a comand const child = nanoprocess(command, args, opts) // open process and query for stats child.open((err) => { child.stat((err, stats) => { console.log(stats) }) }) ``` ## Example The following example spawns a node process that spawns a `sleep` command running for 2 seconds while also doing a lot of work (`Array(10e7).fill(crypto.randomBytes(1024));`). The example will query for process stats and leverage the [progress][progress] module to output process memory and CPU usage. ```js const prettyBytes = require('pretty-bytes') const nanoprocess = require('nanoprocess') const prettyTime = require('pretty-ms') const Progress = require('progress') const template = [ '> :name (:pid)', 'up for :uptime', 'CPU: :cpu%', 'MEM: :mem', ':pidsCount child process(es)' ].join(' | ') const sleep = nanoprocess('node', [ '-e', 'process.title = "sleep";' + 'require("cross-spawn")("sleep", [2]);' + 'Array(10e7).fill(crypto.randomBytes(1024));' ]) const bar = new Progress(template, { width: 20, total: 1 }) sleep.open((err) => { console.log('> opened') let timer = 0 sleep.stat(function onstat(err, stats) { if (stats) { bar.update(0, { pidsCount: stats.pids.length, uptime: prettyTime(stats.uptime), name: stats.name, mem: prettyBytes(stats.memory), cpu: Math.floor(stats.cpu), pid: stats.pid, }) } if (stats && stats.uptime > 2000 && 0 === stats.cpu) { bar.update(1, stats) sleep.close() } else if (!err) { clearTimeout(timer) timer = setTimeout(() => sleep.stat(onstat), 100) } }) sleep.process.on('close', () => { console.log('') console.log('> closed') }) }) ``` ```sh $ node example.js > opened > sleep (33153) | up for 5.2s | CPU: 99% | MEM: 1.25 GB | 1 child process(es) > closed ``` ## API ### `const nanoprocess = require('nanoprocess')` The `nanoprocess` function returns a new [`Process`](#child-process) instance that extends [nanoresource][nanoresource]. ```js const child = nanoprocess('sleep', [2]) child.open((err) => { // process is opened }) ``` ### `const child = nanoprocess(command[, args[, options]])` Create a new [`Process`](#child-process) instance from `command` with optional `args` and `options` that are given to [cross-spawn][cross-spawn] when the [child process is opened](#child-open). ```js const ls = nanoprocess('ls', ['.']) ls.open((err) => { ls.process.stdout.pipe(process.stdout) }) ``` ### `const { Process } = require('nanoprocess')` The `nanoprocess` exports the [`Process`](#child-process) class that can be extended. ```js const { Process } = require('nanoprocess') class InstallDependencies extends Process { constructor(dirname) { super('npm', ['install'], { cwd: dirname }) } } const install = new InstallDependencies('path/to/dir') install.open(() => { // stat loop install.stat(function onstat(err, stats) { console.log(stats) // Stats { cpu: 14.23, ... } install.stat(onstat) }) install.process.on('close', (err) => { console.log('closed') }) }) ``` ### `const child = new Process(command[, args[, options]])` Create a new [`Process`](#child-process) instance from `command` with optional `args` and `options` that are given to [cross-spawn][cross-spawn] when the [child process is opened](#child-open). #### `child.options` The initial `options` given to the [`Process`](#child-process) instance constructor which are given to [cross-spawn][cross-spawn] when the [child process is opened](#child-open). #### `child.command` The command to [spawn][cross-spawn] when the [child process is opened](#child-open). #### `child.process` When the child process is opened, this will be an instance of [`child_process.ChildProcess`]( https://nodejs.org/api/child_process.html#child_process_class_childprocess). #### `child.pid` The child process ID. #### `child.ppid` The child process parent process ID. #### `child.stdin` The child process `stdin` stream. This may be `null`. #### `child.stdout` The child process `stdout` stream. This may be `null`. #### `child.stderr` The child process `stderr` stream. This may be `null`. #### `child.channel` The child process `channel` object. This may be `null`. #### `child.connected` The child process connection state. #### `child.killed` The child process killed state. #### `child.signal` The child process exit signal. This value can be `null`. Check this after the child process has closed. #### `child.code` The child process exit code. This value can be `null`. Check this after the child process has closed. #### `child.args` The arguments for the child process [command](#child-command) given to [cross-spawn][cross-spawn] when the [child process is opened](#child-open). #### `child.open(callback)` Opens the child process by [spawning][cross-spawn] a [command](#child-command) with optional [arguments](#child-args) and [options](#child-options) calling `callback(err)` when opened or if an error occurs during the spawning of the child process. #### `child.close([allowActive[, callback]])` Closes the child process and all decedent child process in the process tree calling `callback(err)` when closed or if an error occurs during the closing of the spawned child process. Setting `allowActive` to `false` (default) will cause a `'SIGTERM'` to be sent to the child process causing it to close. You can call `child.kill({ force: true })` prior to calling this method if you want force the processed to be killed. Set `allowActive` to `true` to wait for the process to close on its and mark the [nanoresource][nanoresource] instance **inactive**. #### `child.kill([opts], callback)` Kill the child process calling `callback` when killed or if can error occurs. Set `opts.true` to force the processed to be killed. #### `child.stat(callback)` Queries for statistics about the running child process for information like [cpu usage](#child-stat-cpu) and [memory consumption](#child-stat-memory) calling `callback(err, stats)` with a stats object or if an error occurs. ```js child.stat((err, stats) => { // handle stats }) ``` The output of the `stats` object may look something like: ```js Stats { bin: 'sleep', uid: 1000, gid: 1000, cpu: 138.46153845657875, pid: 33792, ppid: 33785, pids: [ 33810 ], name: 'sleep', atime: 1572118184405, uptime: 680, memory: 241070080, command: 'node' } ``` ##### `stats.bin` The initial binary used invoke the child process. ##### `stats.uid` The user ID of the child process. ##### `stats.gid` The group ID of the child process. ##### `stats.cpu` The current CPU usage as a percentage of the child process. ##### `stats.pid` The child process ID. ##### `stats.ppid` The parent process ID of the child process. ##### `stats.pids` The child process IDs of the child process ##### `stats.name` The name of process ##### `stats.atime` The time stamp in milliseconds this stat was accessed. ##### `stats.uptime` Time in milliseconds since process spawned ##### `stats.memory` Memory usage in bytes ##### `stats.command` The command used to start the process ##### `stats.isRunning` `true` if the process or any child process in the [pidtree][pidtree] for the root child process [is still running][is-running]. ## See Also - [nanoresource][nanoresource] - [find-process][find-process] - [cross-spawn][cross-spawn] - [pidusage][pidusage] - [pidtree][pidtree] ## License MIT [nanoresource]: https://github.com/mafintosh/nanoresource [find-process]: https://github.com/yibn2008/find-process [cross-spawn]: https://github.com/moxystudio/node-cross-spawn [is-running]: https://github.com/nisaacson/is-running [progress]: https://github.com/visionmedia/node-progress [pidusage]: https://github.com/soyuka/pidusage [pidtree]: https://github.com/simonepri/pidtree --- _Source: https://npm.io/package/nanoprocess · Machine-readable twin of the npm.io package page. 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