823 lines
24 KiB
Markdown
823 lines
24 KiB
Markdown
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<picture>
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<source media="(prefers-color-scheme: dark)" srcset="media/logo_dark.svg">
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<img alt="execa logo" src="media/logo.svg" width="400">
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</picture>
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<br>
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[![Coverage Status](https://codecov.io/gh/sindresorhus/execa/branch/main/graph/badge.svg)](https://codecov.io/gh/sindresorhus/execa)
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> Process execution for humans
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<br>
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---
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<div align="center">
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<p>
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<p>
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<sup>
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<a href="https://github.com/sponsors/sindresorhus">Sindre's open source work is supported by the community</a>
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</sup>
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</p>
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<sup>Special thanks to:</sup>
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<br>
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<br>
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<a href="https://transloadit.com?utm_source=sindresorhus&utm_medium=referral&utm_campaign=sponsorship&utm_content=execa">
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<picture>
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<source width="360" media="(prefers-color-scheme: dark)" srcset="https://sindresorhus.com/assets/thanks/transloadit-logo-dark.svg">
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<source width="360" media="(prefers-color-scheme: light)" srcset="https://sindresorhus.com/assets/thanks/transloadit-logo.svg">
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<img width="360" src="https://sindresorhus.com/assets/thanks/transloadit-logo.svg" alt="Transloadit logo">
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</picture>
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</a>
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<br>
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<br>
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</p>
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</div>
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---
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<br>
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## Why
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This package improves [`child_process`](https://nodejs.org/api/child_process.html) methods with:
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- [Promise interface](#execacommandcommand-options).
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- [Scripts interface](#scripts-interface), like `zx`.
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- Improved [Windows support](https://github.com/IndigoUnited/node-cross-spawn#why), including [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) binaries.
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- Executes [locally installed binaries](#preferlocal) without `npx`.
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- [Cleans up](#cleanup) child processes when the parent process ends.
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- [Graceful termination](#optionsforcekillaftertimeout).
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- Get [interleaved output](#all) from `stdout` and `stderr` similar to what is printed on the terminal.
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- [Strips the final newline](#stripfinalnewline) from the output so you don't have to do `stdout.trim()`.
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- Convenience methods to pipe processes' [input](#input) and [output](#redirect-output-to-a-file).
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- Can specify file and arguments [as a single string](#execacommandcommand-options) without a shell.
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- [Verbose mode](#verbose-mode) for debugging.
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- More descriptive errors.
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- Higher max buffer: 100 MB instead of 1 MB.
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## Install
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```sh
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npm install execa
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```
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## Usage
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### Promise interface
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```js
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import {execa} from 'execa';
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const {stdout} = await execa('echo', ['unicorns']);
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console.log(stdout);
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//=> 'unicorns'
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```
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### Scripts interface
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For more information about Execa scripts, please see [this page](docs/scripts.md).
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#### Basic
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```js
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import {$} from 'execa';
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const branch = await $`git branch --show-current`;
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await $`dep deploy --branch=${branch}`;
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```
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#### Multiple arguments
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```js
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import {$} from 'execa';
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const args = ['unicorns', '&', 'rainbows!'];
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const {stdout} = await $`echo ${args}`;
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console.log(stdout);
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//=> 'unicorns & rainbows!'
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```
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#### With options
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```js
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import {$} from 'execa';
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await $({stdio: 'inherit'})`echo unicorns`;
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//=> 'unicorns'
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```
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#### Shared options
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```js
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import {$} from 'execa';
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const $$ = $({stdio: 'inherit'});
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await $$`echo unicorns`;
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//=> 'unicorns'
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await $$`echo rainbows`;
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//=> 'rainbows'
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```
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#### Verbose mode
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```sh
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> node file.js
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unicorns
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rainbows
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> NODE_DEBUG=execa node file.js
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[16:50:03.305] echo unicorns
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unicorns
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[16:50:03.308] echo rainbows
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rainbows
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```
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### Input/output
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#### Redirect output to a file
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```js
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import {execa} from 'execa';
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// Similar to `echo unicorns > stdout.txt` in Bash
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await execa('echo', ['unicorns']).pipeStdout('stdout.txt');
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// Similar to `echo unicorns 2> stdout.txt` in Bash
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await execa('echo', ['unicorns']).pipeStderr('stderr.txt');
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// Similar to `echo unicorns &> stdout.txt` in Bash
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await execa('echo', ['unicorns'], {all: true}).pipeAll('all.txt');
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```
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#### Redirect input from a file
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```js
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import {execa} from 'execa';
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// Similar to `cat < stdin.txt` in Bash
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const {stdout} = await execa('cat', {inputFile: 'stdin.txt'});
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console.log(stdout);
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//=> 'unicorns'
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```
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#### Save and pipe output from a child process
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```js
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import {execa} from 'execa';
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const {stdout} = await execa('echo', ['unicorns']).pipeStdout(process.stdout);
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// Prints `unicorns`
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console.log(stdout);
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// Also returns 'unicorns'
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```
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#### Pipe multiple processes
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```js
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import {execa} from 'execa';
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// Similar to `echo unicorns | cat` in Bash
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const {stdout} = await execa('echo', ['unicorns']).pipeStdout(execa('cat'));
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console.log(stdout);
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//=> 'unicorns'
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```
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### Handling Errors
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```js
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import {execa} from 'execa';
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// Catching an error
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try {
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await execa('unknown', ['command']);
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} catch (error) {
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console.log(error);
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/*
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{
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message: 'Command failed with ENOENT: unknown command spawn unknown ENOENT',
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errno: -2,
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code: 'ENOENT',
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syscall: 'spawn unknown',
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path: 'unknown',
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spawnargs: ['command'],
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originalMessage: 'spawn unknown ENOENT',
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shortMessage: 'Command failed with ENOENT: unknown command spawn unknown ENOENT',
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command: 'unknown command',
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escapedCommand: 'unknown command',
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stdout: '',
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stderr: '',
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failed: true,
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timedOut: false,
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isCanceled: false,
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killed: false
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}
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*/
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}
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```
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### Graceful termination
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Using SIGTERM, and after 2 seconds, kill it with SIGKILL.
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```js
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const subprocess = execa('node');
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setTimeout(() => {
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subprocess.kill('SIGTERM', {
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forceKillAfterTimeout: 2000
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});
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}, 1000);
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```
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## API
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### Methods
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#### execa(file, arguments?, options?)
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Executes a command using `file ...arguments`. `arguments` are specified as an array of strings. Returns a [`childProcess`](#childprocess).
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Arguments are [automatically escaped](#shell-syntax). They can contain any character, including spaces.
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This is the preferred method when executing single commands.
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#### execaNode(scriptPath, arguments?, options?)
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Executes a Node.js file using `node scriptPath ...arguments`. `arguments` are specified as an array of strings. Returns a [`childProcess`](#childprocess).
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Arguments are [automatically escaped](#shell-syntax). They can contain any character, including spaces.
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This is the preferred method when executing Node.js files.
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Like [`child_process#fork()`](https://nodejs.org/api/child_process.html#child_process_child_process_fork_modulepath_args_options):
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- the current Node version and options are used. This can be overridden using the [`nodePath`](#nodepath-for-node-only) and [`nodeOptions`](#nodeoptions-for-node-only) options.
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- the [`shell`](#shell) option cannot be used
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- an extra channel [`ipc`](https://nodejs.org/api/child_process.html#child_process_options_stdio) is passed to [`stdio`](#stdio)
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#### $\`command\`
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Executes a command. The `command` string includes both the `file` and its `arguments`. Returns a [`childProcess`](#childprocess).
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Arguments are [automatically escaped](#shell-syntax). They can contain any character, but spaces must use `${}` like `` $`echo ${'has space'}` ``.
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This is the preferred method when executing multiple commands in a script file.
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The `command` string can inject any `${value}` with the following types: string, number, [`childProcess`](#childprocess) or an array of those types. For example: `` $`echo one ${'two'} ${3} ${['four', 'five']}` ``. For `${childProcess}`, the process's `stdout` is used.
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For more information, please see [this section](#scripts-interface) and [this page](docs/scripts.md).
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#### $(options)
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Returns a new instance of [`$`](#command) but with different default `options`. Consecutive calls are merged to previous ones.
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This can be used to either:
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- Set options for a specific command: `` $(options)`command` ``
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- Share options for multiple commands: `` const $$ = $(options); $$`command`; $$`otherCommand`; ``
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#### execaCommand(command, options?)
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Executes a command. The `command` string includes both the `file` and its `arguments`. Returns a [`childProcess`](#childprocess).
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Arguments are [automatically escaped](#shell-syntax). They can contain any character, but spaces must be escaped with a backslash like `execaCommand('echo has\\ space')`.
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This is the preferred method when executing a user-supplied `command` string, such as in a REPL.
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### execaSync(file, arguments?, options?)
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Same as [`execa()`](#execacommandcommand-options) but synchronous.
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Returns or throws a [`childProcessResult`](#childProcessResult).
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### $.sync\`command\`
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Same as [$\`command\`](#command) but synchronous.
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Returns or throws a [`childProcessResult`](#childProcessResult).
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### execaCommandSync(command, options?)
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Same as [`execaCommand()`](#execacommand-command-options) but synchronous.
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Returns or throws a [`childProcessResult`](#childProcessResult).
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### Shell syntax
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For all the [methods above](#methods), no shell interpreter (Bash, cmd.exe, etc.) is used unless the [`shell` option](#shell) is set. This means shell-specific characters and expressions (`$variable`, `&&`, `||`, `;`, `|`, etc.) have no special meaning and do not need to be escaped.
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### childProcess
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The return value of all [asynchronous methods](#methods) is both:
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- a `Promise` resolving or rejecting with a [`childProcessResult`](#childProcessResult).
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- a [`child_process` instance](https://nodejs.org/api/child_process.html#child_process_class_childprocess) with the following additional methods and properties.
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#### kill(signal?, options?)
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Same as the original [`child_process#kill()`](https://nodejs.org/api/child_process.html#child_process_subprocess_kill_signal) except: if `signal` is `SIGTERM` (the default value) and the child process is not terminated after 5 seconds, force it by sending `SIGKILL`.
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Note that this graceful termination does not work on Windows, because Windows [doesn't support signals](https://nodejs.org/api/process.html#process_signal_events) (`SIGKILL` and `SIGTERM` has the same effect of force-killing the process immediately.) If you want to achieve graceful termination on Windows, you have to use other means, such as [`taskkill`](https://github.com/sindresorhus/taskkill).
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##### options.forceKillAfterTimeout
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Type: `number | false`\
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Default: `5000`
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Milliseconds to wait for the child process to terminate before sending `SIGKILL`.
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Can be disabled with `false`.
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#### all
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Type: `ReadableStream | undefined`
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Stream combining/interleaving [`stdout`](https://nodejs.org/api/child_process.html#child_process_subprocess_stdout) and [`stderr`](https://nodejs.org/api/child_process.html#child_process_subprocess_stderr).
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This is `undefined` if either:
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- the [`all` option](#all-2) is `false` (the default value)
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- both [`stdout`](#stdout-1) and [`stderr`](#stderr-1) options are set to [`'inherit'`, `'ipc'`, `Stream` or `integer`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio)
|
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#### pipeStdout(target)
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[Pipe](https://nodejs.org/api/stream.html#readablepipedestination-options) the child process's `stdout` to `target`, which can be:
|
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- Another [`execa()` return value](#pipe-multiple-processes)
|
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- A [writable stream](#save-and-pipe-output-from-a-child-process)
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- A [file path string](#redirect-output-to-a-file)
|
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If the `target` is another [`execa()` return value](#execacommandcommand-options), it is returned. Otherwise, the original `execa()` return value is returned. This allows chaining `pipeStdout()` then `await`ing the [final result](#childprocessresult).
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The [`stdout` option](#stdout-1) must be kept as `pipe`, its default value.
|
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|
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#### pipeStderr(target)
|
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|
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Like [`pipeStdout()`](#pipestdouttarget) but piping the child process's `stderr` instead.
|
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The [`stderr` option](#stderr-1) must be kept as `pipe`, its default value.
|
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#### pipeAll(target)
|
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Combines both [`pipeStdout()`](#pipestdouttarget) and [`pipeStderr()`](#pipestderrtarget).
|
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|
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Either the [`stdout` option](#stdout-1) or the [`stderr` option](#stderr-1) must be kept as `pipe`, their default value. Also, the [`all` option](#all-2) must be set to `true`.
|
||
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### childProcessResult
|
||
|
|
||
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Type: `object`
|
||
|
|
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Result of a child process execution. On success this is a plain object. On failure this is also an `Error` instance.
|
||
|
|
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The child process [fails](#failed) when:
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- its [exit code](#exitcode) is not `0`
|
||
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- it was [killed](#killed) with a [signal](#signal)
|
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- [timing out](#timedout)
|
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- [being canceled](#iscanceled)
|
||
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- there's not enough memory or there are already too many child processes
|
||
|
|
||
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#### command
|
||
|
|
||
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Type: `string`
|
||
|
|
||
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The file and arguments that were run, for logging purposes.
|
||
|
|
||
|
This is not escaped and should not be executed directly as a process, including using [`execa()`](#execafile-arguments-options) or [`execaCommand()`](#execacommandcommand-options).
|
||
|
|
||
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#### escapedCommand
|
||
|
|
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|
Type: `string`
|
||
|
|
||
|
Same as [`command`](#command-1) but escaped.
|
||
|
|
||
|
This is meant to be copy and pasted into a shell, for debugging purposes.
|
||
|
Since the escaping is fairly basic, this should not be executed directly as a process, including using [`execa()`](#execafile-arguments-options) or [`execaCommand()`](#execacommandcommand-options).
|
||
|
|
||
|
#### exitCode
|
||
|
|
||
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Type: `number`
|
||
|
|
||
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The numeric exit code of the process that was run.
|
||
|
|
||
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#### stdout
|
||
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|
||
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Type: `string | Buffer`
|
||
|
|
||
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The output of the process on stdout.
|
||
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|
||
|
#### stderr
|
||
|
|
||
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Type: `string | Buffer`
|
||
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|
||
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The output of the process on stderr.
|
||
|
|
||
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#### all
|
||
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|
||
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Type: `string | Buffer | undefined`
|
||
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|
||
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The output of the process with `stdout` and `stderr` interleaved.
|
||
|
|
||
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This is `undefined` if either:
|
||
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- the [`all` option](#all-2) is `false` (the default value)
|
||
|
- `execaSync()` was used
|
||
|
|
||
|
#### failed
|
||
|
|
||
|
Type: `boolean`
|
||
|
|
||
|
Whether the process failed to run.
|
||
|
|
||
|
#### timedOut
|
||
|
|
||
|
Type: `boolean`
|
||
|
|
||
|
Whether the process timed out.
|
||
|
|
||
|
#### isCanceled
|
||
|
|
||
|
Type: `boolean`
|
||
|
|
||
|
Whether the process was canceled.
|
||
|
|
||
|
You can cancel the spawned process using the [`signal`](#signal-1) option.
|
||
|
|
||
|
#### killed
|
||
|
|
||
|
Type: `boolean`
|
||
|
|
||
|
Whether the process was killed.
|
||
|
|
||
|
#### signal
|
||
|
|
||
|
Type: `string | undefined`
|
||
|
|
||
|
The name of the signal that was used to terminate the process. For example, `SIGFPE`.
|
||
|
|
||
|
If a signal terminated the process, this property is defined and included in the error message. Otherwise it is `undefined`.
|
||
|
|
||
|
#### signalDescription
|
||
|
|
||
|
Type: `string | undefined`
|
||
|
|
||
|
A human-friendly description of the signal that was used to terminate the process. For example, `Floating point arithmetic error`.
|
||
|
|
||
|
If a signal terminated the process, this property is defined and included in the error message. Otherwise it is `undefined`. It is also `undefined` when the signal is very uncommon which should seldomly happen.
|
||
|
|
||
|
#### cwd
|
||
|
|
||
|
Type: `string`
|
||
|
|
||
|
The `cwd` of the command if provided in the [command options](#cwd-1). Otherwise it is `process.cwd()`.
|
||
|
|
||
|
#### message
|
||
|
|
||
|
Type: `string`
|
||
|
|
||
|
Error message when the child process failed to run. In addition to the [underlying error message](#originalMessage), it also contains some information related to why the child process errored.
|
||
|
|
||
|
The child process [stderr](#stderr) then [stdout](#stdout) are appended to the end, separated with newlines and not interleaved.
|
||
|
|
||
|
#### shortMessage
|
||
|
|
||
|
Type: `string`
|
||
|
|
||
|
This is the same as the [`message` property](#message) except it does not include the child process stdout/stderr.
|
||
|
|
||
|
#### originalMessage
|
||
|
|
||
|
Type: `string | undefined`
|
||
|
|
||
|
Original error message. This is the same as the `message` property except it includes neither the child process stdout/stderr nor some additional information added by Execa.
|
||
|
|
||
|
This is `undefined` unless the child process exited due to an `error` event or a timeout.
|
||
|
|
||
|
### options
|
||
|
|
||
|
Type: `object`
|
||
|
|
||
|
#### cleanup
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
Kill the spawned process when the parent process exits unless either:
|
||
|
- the spawned process is [`detached`](https://nodejs.org/api/child_process.html#child_process_options_detached)
|
||
|
- the parent process is terminated abruptly, for example, with `SIGKILL` as opposed to `SIGTERM` or a normal exit
|
||
|
|
||
|
#### preferLocal
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true` with [`$`](#command), `false` otherwise
|
||
|
|
||
|
Prefer locally installed binaries when looking for a binary to execute.\
|
||
|
If you `$ npm install foo`, you can then `execa('foo')`.
|
||
|
|
||
|
#### localDir
|
||
|
|
||
|
Type: `string | URL`\
|
||
|
Default: `process.cwd()`
|
||
|
|
||
|
Preferred path to find locally installed binaries in (use with `preferLocal`).
|
||
|
|
||
|
#### execPath
|
||
|
|
||
|
Type: `string`\
|
||
|
Default: `process.execPath` (Current Node.js executable)
|
||
|
|
||
|
Path to the Node.js executable to use in child processes.
|
||
|
|
||
|
This can be either an absolute path or a path relative to the [`cwd` option](#cwd).
|
||
|
|
||
|
Requires [`preferLocal`](#preferlocal) to be `true`.
|
||
|
|
||
|
For example, this can be used together with [`get-node`](https://github.com/ehmicky/get-node) to run a specific Node.js version in a child process.
|
||
|
|
||
|
#### buffer
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
Buffer the output from the spawned process. When set to `false`, you must read the output of [`stdout`](#stdout-1) and [`stderr`](#stderr-1) (or [`all`](#all) if the [`all`](#all-2) option is `true`). Otherwise the returned promise will not be resolved/rejected.
|
||
|
|
||
|
If the spawned process fails, [`error.stdout`](#stdout), [`error.stderr`](#stderr), and [`error.all`](#all) will contain the buffered data.
|
||
|
|
||
|
#### input
|
||
|
|
||
|
Type: `string | Buffer | stream.Readable`
|
||
|
|
||
|
Write some input to the `stdin` of your binary.\
|
||
|
Streams are not allowed when using the synchronous methods.
|
||
|
|
||
|
If the input is a file, use the [`inputFile` option](#inputfile) instead.
|
||
|
|
||
|
#### inputFile
|
||
|
|
||
|
Type: `string`
|
||
|
|
||
|
Use a file as input to the the `stdin` of your binary.
|
||
|
|
||
|
If the input is not a file, use the [`input` option](#input) instead.
|
||
|
|
||
|
#### stdin
|
||
|
|
||
|
Type: `string | number | Stream | undefined`\
|
||
|
Default: `inherit` with [`$`](#command), `pipe` otherwise
|
||
|
|
||
|
Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio).
|
||
|
|
||
|
#### stdout
|
||
|
|
||
|
Type: `string | number | Stream | undefined`\
|
||
|
Default: `pipe`
|
||
|
|
||
|
Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio).
|
||
|
|
||
|
#### stderr
|
||
|
|
||
|
Type: `string | number | Stream | undefined`\
|
||
|
Default: `pipe`
|
||
|
|
||
|
Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio).
|
||
|
|
||
|
#### all
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `false`
|
||
|
|
||
|
Add an `.all` property on the [promise](#all) and the [resolved value](#all-1). The property contains the output of the process with `stdout` and `stderr` interleaved.
|
||
|
|
||
|
#### reject
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
Setting this to `false` resolves the promise with the error instead of rejecting it.
|
||
|
|
||
|
#### stripFinalNewline
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
Strip the final [newline character](https://en.wikipedia.org/wiki/Newline) from the output.
|
||
|
|
||
|
#### extendEnv
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
Set to `false` if you don't want to extend the environment variables when providing the `env` property.
|
||
|
|
||
|
---
|
||
|
|
||
|
Execa also accepts the below options which are the same as the options for [`child_process#spawn()`](https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options)/[`child_process#exec()`](https://nodejs.org/api/child_process.html#child_process_child_process_exec_command_options_callback)
|
||
|
|
||
|
#### cwd
|
||
|
|
||
|
Type: `string | URL`\
|
||
|
Default: `process.cwd()`
|
||
|
|
||
|
Current working directory of the child process.
|
||
|
|
||
|
#### env
|
||
|
|
||
|
Type: `object`\
|
||
|
Default: `process.env`
|
||
|
|
||
|
Environment key-value pairs. Extends automatically from `process.env`. Set [`extendEnv`](#extendenv) to `false` if you don't want this.
|
||
|
|
||
|
#### argv0
|
||
|
|
||
|
Type: `string`
|
||
|
|
||
|
Explicitly set the value of `argv[0]` sent to the child process. This will be set to `file` if not specified.
|
||
|
|
||
|
#### stdio
|
||
|
|
||
|
Type: `string | string[]`\
|
||
|
Default: `pipe`
|
||
|
|
||
|
Child's [stdio](https://nodejs.org/api/child_process.html#child_process_options_stdio) configuration.
|
||
|
|
||
|
#### serialization
|
||
|
|
||
|
Type: `string`\
|
||
|
Default: `'json'`
|
||
|
|
||
|
Specify the kind of serialization used for sending messages between processes when using the [`stdio: 'ipc'`](#stdio) option or [`execaNode()`](#execanodescriptpath-arguments-options):
|
||
|
- `json`: Uses `JSON.stringify()` and `JSON.parse()`.
|
||
|
- `advanced`: Uses [`v8.serialize()`](https://nodejs.org/api/v8.html#v8_v8_serialize_value)
|
||
|
|
||
|
[More info.](https://nodejs.org/api/child_process.html#child_process_advanced_serialization)
|
||
|
|
||
|
#### detached
|
||
|
|
||
|
Type: `boolean`
|
||
|
|
||
|
Prepare child to run independently of its parent process. Specific behavior [depends on the platform](https://nodejs.org/api/child_process.html#child_process_options_detached).
|
||
|
|
||
|
#### uid
|
||
|
|
||
|
Type: `number`
|
||
|
|
||
|
Sets the user identity of the process.
|
||
|
|
||
|
#### gid
|
||
|
|
||
|
Type: `number`
|
||
|
|
||
|
Sets the group identity of the process.
|
||
|
|
||
|
#### shell
|
||
|
|
||
|
Type: `boolean | string`\
|
||
|
Default: `false`
|
||
|
|
||
|
If `true`, runs `file` inside of a shell. Uses `/bin/sh` on UNIX and `cmd.exe` on Windows. A different shell can be specified as a string. The shell should understand the `-c` switch on UNIX or `/d /s /c` on Windows.
|
||
|
|
||
|
We recommend against using this option since it is:
|
||
|
- not cross-platform, encouraging shell-specific syntax.
|
||
|
- slower, because of the additional shell interpretation.
|
||
|
- unsafe, potentially allowing command injection.
|
||
|
|
||
|
#### encoding
|
||
|
|
||
|
Type: `string | null`\
|
||
|
Default: `utf8`
|
||
|
|
||
|
Specify the character encoding used to decode the `stdout` and `stderr` output. If set to `'buffer'` or `null`, then `stdout` and `stderr` will be a `Buffer` instead of a string.
|
||
|
|
||
|
#### timeout
|
||
|
|
||
|
Type: `number`\
|
||
|
Default: `0`
|
||
|
|
||
|
If timeout is greater than `0`, the parent will send the signal identified by the `killSignal` property (the default is `SIGTERM`) if the child runs longer than timeout milliseconds.
|
||
|
|
||
|
#### maxBuffer
|
||
|
|
||
|
Type: `number`\
|
||
|
Default: `100_000_000` (100 MB)
|
||
|
|
||
|
Largest amount of data in bytes allowed on `stdout` or `stderr`.
|
||
|
|
||
|
#### killSignal
|
||
|
|
||
|
Type: `string | number`\
|
||
|
Default: `SIGTERM`
|
||
|
|
||
|
Signal value to be used when the spawned process will be killed.
|
||
|
|
||
|
#### signal
|
||
|
|
||
|
Type: [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal)
|
||
|
|
||
|
You can abort the spawned process using [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController).
|
||
|
|
||
|
When `AbortController.abort()` is called, [`.isCanceled`](#iscanceled) becomes `true`.
|
||
|
|
||
|
#### windowsVerbatimArguments
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `false`
|
||
|
|
||
|
If `true`, no quoting or escaping of arguments is done on Windows. Ignored on other platforms. This is set to `true` automatically when the `shell` option is `true`.
|
||
|
|
||
|
#### windowsHide
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `true`
|
||
|
|
||
|
On Windows, do not create a new console window. Please note this also prevents `CTRL-C` [from working](https://github.com/nodejs/node/issues/29837) on Windows.
|
||
|
|
||
|
#### verbose
|
||
|
|
||
|
Type: `boolean`\
|
||
|
Default: `false`
|
||
|
|
||
|
[Print each command](#verbose-mode) on `stderr` before executing it.
|
||
|
|
||
|
This can also be enabled by setting the `NODE_DEBUG=execa` environment variable in the current process.
|
||
|
|
||
|
#### nodePath *(For `.node()` only)*
|
||
|
|
||
|
Type: `string`\
|
||
|
Default: [`process.execPath`](https://nodejs.org/api/process.html#process_process_execpath)
|
||
|
|
||
|
Node.js executable used to create the child process.
|
||
|
|
||
|
#### nodeOptions *(For `.node()` only)*
|
||
|
|
||
|
Type: `string[]`\
|
||
|
Default: [`process.execArgv`](https://nodejs.org/api/process.html#process_process_execargv)
|
||
|
|
||
|
List of [CLI options](https://nodejs.org/api/cli.html#cli_options) passed to the Node.js executable.
|
||
|
|
||
|
## Tips
|
||
|
|
||
|
### Retry on error
|
||
|
|
||
|
Gracefully handle failures by using automatic retries and exponential backoff with the [`p-retry`](https://github.com/sindresorhus/p-retry) package:
|
||
|
|
||
|
```js
|
||
|
import pRetry from 'p-retry';
|
||
|
|
||
|
const run = async () => {
|
||
|
const results = await execa('curl', ['-sSL', 'https://sindresorhus.com/unicorn']);
|
||
|
return results;
|
||
|
};
|
||
|
|
||
|
console.log(await pRetry(run, {retries: 5}));
|
||
|
```
|
||
|
|
||
|
### Cancelling a spawned process
|
||
|
|
||
|
```js
|
||
|
import {execa} from 'execa';
|
||
|
|
||
|
const abortController = new AbortController();
|
||
|
const subprocess = execa('node', [], {signal: abortController.signal});
|
||
|
|
||
|
setTimeout(() => {
|
||
|
abortController.abort();
|
||
|
}, 1000);
|
||
|
|
||
|
try {
|
||
|
await subprocess;
|
||
|
} catch (error) {
|
||
|
console.log(subprocess.killed); // true
|
||
|
console.log(error.isCanceled); // true
|
||
|
}
|
||
|
```
|
||
|
|
||
|
### Execute the current package's binary
|
||
|
|
||
|
```js
|
||
|
import {getBinPath} from 'get-bin-path';
|
||
|
|
||
|
const binPath = await getBinPath();
|
||
|
await execa(binPath);
|
||
|
```
|
||
|
|
||
|
`execa` can be combined with [`get-bin-path`](https://github.com/ehmicky/get-bin-path) to test the current package's binary. As opposed to hard-coding the path to the binary, this validates that the `package.json` `bin` field is correctly set up.
|
||
|
|
||
|
## Related
|
||
|
|
||
|
- [gulp-execa](https://github.com/ehmicky/gulp-execa) - Gulp plugin for `execa`
|
||
|
- [nvexeca](https://github.com/ehmicky/nvexeca) - Run `execa` using any Node.js version
|
||
|
- [sudo-prompt](https://github.com/jorangreef/sudo-prompt) - Run commands with elevated privileges.
|
||
|
|
||
|
## Maintainers
|
||
|
|
||
|
- [Sindre Sorhus](https://github.com/sindresorhus)
|
||
|
- [@ehmicky](https://github.com/ehmicky)
|
||
|
|
||
|
---
|
||
|
|
||
|
<div align="center">
|
||
|
<b>
|
||
|
<a href="https://tidelift.com/subscription/pkg/npm-execa?utm_source=npm-execa&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
|
||
|
</b>
|
||
|
<br>
|
||
|
<sub>
|
||
|
Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
|
||
|
</sub>
|
||
|
</div>
|