readme.md (24960B)
1 <picture> 2 <source media="(prefers-color-scheme: dark)" srcset="media/logo_dark.svg"> 3 <img alt="execa logo" src="media/logo.svg" width="400"> 4 </picture> 5 <br> 6 7 [](https://codecov.io/gh/sindresorhus/execa) 8 9 > Process execution for humans 10 11 <br> 12 13 --- 14 15 <div align="center"> 16 <p> 17 <p> 18 <sup> 19 <a href="https://github.com/sponsors/sindresorhus">Sindre's open source work is supported by the community</a> 20 </sup> 21 </p> 22 <sup>Special thanks to:</sup> 23 <br> 24 <br> 25 <a href="https://transloadit.com"> 26 <picture> 27 <source width="360" media="(prefers-color-scheme: dark)" srcset="https://sindresorhus.com/assets/thanks/transloadit-logo-dark.svg"> 28 <source width="360" media="(prefers-color-scheme: light)" srcset="https://sindresorhus.com/assets/thanks/transloadit-logo.svg"> 29 <img width="360" src="https://sindresorhus.com/assets/thanks/transloadit-logo.svg" alt="Transloadit logo"> 30 </picture> 31 </a> 32 <br> 33 <br> 34 </p> 35 </div> 36 37 --- 38 39 <br> 40 41 ## Why 42 43 This package improves [`child_process`](https://nodejs.org/api/child_process.html) methods with: 44 45 - [Promise interface](#execacommandcommand-options). 46 - [Scripts interface](#scripts-interface), like `zx`. 47 - Improved [Windows support](https://github.com/IndigoUnited/node-cross-spawn#why), including [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) binaries. 48 - Executes [locally installed binaries](#preferlocal) without `npx`. 49 - [Cleans up](#cleanup) child processes when the parent process ends. 50 - [Graceful termination](#optionsforcekillaftertimeout). 51 - Get [interleaved output](#all) from `stdout` and `stderr` similar to what is printed on the terminal. 52 - [Strips the final newline](#stripfinalnewline) from the output so you don't have to do `stdout.trim()`. 53 - Convenience methods to pipe processes' [input](#input) and [output](#redirect-output-to-a-file). 54 - Can specify file and arguments [as a single string](#execacommandcommand-options) without a shell. 55 - [Verbose mode](#verbose-mode) for debugging. 56 - More descriptive errors. 57 - Higher max buffer: 100 MB instead of 1 MB. 58 59 ## Install 60 61 ```sh 62 npm install execa 63 ``` 64 65 ## Usage 66 67 ### Promise interface 68 69 ```js 70 import {execa} from 'execa'; 71 72 const {stdout} = await execa('echo', ['unicorns']); 73 console.log(stdout); 74 //=> 'unicorns' 75 ``` 76 77 ### Scripts interface 78 79 For more information about Execa scripts, please see [this page](docs/scripts.md). 80 81 #### Basic 82 83 ```js 84 import {$} from 'execa'; 85 86 const branch = await $`git branch --show-current`; 87 await $`dep deploy --branch=${branch}`; 88 ``` 89 90 #### Multiple arguments 91 92 ```js 93 import {$} from 'execa'; 94 95 const args = ['unicorns', '&', 'rainbows!']; 96 const {stdout} = await $`echo ${args}`; 97 console.log(stdout); 98 //=> 'unicorns & rainbows!' 99 ``` 100 101 #### With options 102 103 ```js 104 import {$} from 'execa'; 105 106 await $({stdio: 'inherit'})`echo unicorns`; 107 //=> 'unicorns' 108 ``` 109 110 #### Shared options 111 112 ```js 113 import {$} from 'execa'; 114 115 const $$ = $({stdio: 'inherit'}); 116 117 await $$`echo unicorns`; 118 //=> 'unicorns' 119 120 await $$`echo rainbows`; 121 //=> 'rainbows' 122 ``` 123 124 #### Verbose mode 125 126 ```sh 127 > node file.js 128 unicorns 129 rainbows 130 131 > NODE_DEBUG=execa node file.js 132 [16:50:03.305] echo unicorns 133 unicorns 134 [16:50:03.308] echo rainbows 135 rainbows 136 ``` 137 138 ### Input/output 139 140 #### Redirect output to a file 141 142 ```js 143 import {execa} from 'execa'; 144 145 // Similar to `echo unicorns > stdout.txt` in Bash 146 await execa('echo', ['unicorns']).pipeStdout('stdout.txt'); 147 148 // Similar to `echo unicorns 2> stdout.txt` in Bash 149 await execa('echo', ['unicorns']).pipeStderr('stderr.txt'); 150 151 // Similar to `echo unicorns &> stdout.txt` in Bash 152 await execa('echo', ['unicorns'], {all: true}).pipeAll('all.txt'); 153 ``` 154 155 #### Redirect input from a file 156 157 ```js 158 import {execa} from 'execa'; 159 160 // Similar to `cat < stdin.txt` in Bash 161 const {stdout} = await execa('cat', {inputFile: 'stdin.txt'}); 162 console.log(stdout); 163 //=> 'unicorns' 164 ``` 165 166 #### Save and pipe output from a child process 167 168 ```js 169 import {execa} from 'execa'; 170 171 const {stdout} = await execa('echo', ['unicorns']).pipeStdout(process.stdout); 172 // Prints `unicorns` 173 console.log(stdout); 174 // Also returns 'unicorns' 175 ``` 176 177 #### Pipe multiple processes 178 179 ```js 180 import {execa} from 'execa'; 181 182 // Similar to `echo unicorns | cat` in Bash 183 const {stdout} = await execa('echo', ['unicorns']).pipeStdout(execa('cat')); 184 console.log(stdout); 185 //=> 'unicorns' 186 ``` 187 188 ### Handling Errors 189 190 ```js 191 import {execa} from 'execa'; 192 193 // Catching an error 194 try { 195 await execa('unknown', ['command']); 196 } catch (error) { 197 console.log(error); 198 /* 199 { 200 message: 'Command failed with ENOENT: unknown command spawn unknown ENOENT', 201 errno: -2, 202 code: 'ENOENT', 203 syscall: 'spawn unknown', 204 path: 'unknown', 205 spawnargs: ['command'], 206 originalMessage: 'spawn unknown ENOENT', 207 shortMessage: 'Command failed with ENOENT: unknown command spawn unknown ENOENT', 208 command: 'unknown command', 209 escapedCommand: 'unknown command', 210 stdout: '', 211 stderr: '', 212 failed: true, 213 timedOut: false, 214 isCanceled: false, 215 killed: false 216 } 217 */ 218 } 219 ``` 220 221 ### Graceful termination 222 223 Using SIGTERM, and after 2 seconds, kill it with SIGKILL. 224 225 ```js 226 const subprocess = execa('node'); 227 228 setTimeout(() => { 229 subprocess.kill('SIGTERM', { 230 forceKillAfterTimeout: 2000 231 }); 232 }, 1000); 233 ``` 234 235 ## API 236 237 ### Methods 238 239 #### execa(file, arguments?, options?) 240 241 Executes a command using `file ...arguments`. `arguments` are specified as an array of strings. Returns a [`childProcess`](#childprocess). 242 243 Arguments are [automatically escaped](#shell-syntax). They can contain any character, including spaces. 244 245 This is the preferred method when executing single commands. 246 247 #### execaNode(scriptPath, arguments?, options?) 248 249 Executes a Node.js file using `node scriptPath ...arguments`. `arguments` are specified as an array of strings. Returns a [`childProcess`](#childprocess). 250 251 Arguments are [automatically escaped](#shell-syntax). They can contain any character, including spaces. 252 253 This is the preferred method when executing Node.js files. 254 255 Like [`child_process#fork()`](https://nodejs.org/api/child_process.html#child_process_child_process_fork_modulepath_args_options): 256 - 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. 257 - the [`shell`](#shell) option cannot be used 258 - an extra channel [`ipc`](https://nodejs.org/api/child_process.html#child_process_options_stdio) is passed to [`stdio`](#stdio) 259 260 #### $\`command\` 261 262 Executes a command. The `command` string includes both the `file` and its `arguments`. Returns a [`childProcess`](#childprocess). 263 264 Arguments are [automatically escaped](#shell-syntax). They can contain any character, but spaces must use `${}` like `` $`echo ${'has space'}` ``. 265 266 This is the preferred method when executing multiple commands in a script file. 267 268 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. 269 270 For more information, please see [this section](#scripts-interface) and [this page](docs/scripts.md). 271 272 #### $(options) 273 274 Returns a new instance of [`$`](#command) but with different default `options`. Consecutive calls are merged to previous ones. 275 276 This can be used to either: 277 - Set options for a specific command: `` $(options)`command` `` 278 - Share options for multiple commands: `` const $$ = $(options); $$`command`; $$`otherCommand`; `` 279 280 #### execaCommand(command, options?) 281 282 Executes a command. The `command` string includes both the `file` and its `arguments`. Returns a [`childProcess`](#childprocess). 283 284 Arguments are [automatically escaped](#shell-syntax). They can contain any character, but spaces must be escaped with a backslash like `execaCommand('echo has\\ space')`. 285 286 This is the preferred method when executing a user-supplied `command` string, such as in a REPL. 287 288 ### execaSync(file, arguments?, options?) 289 290 Same as [`execa()`](#execacommandcommand-options) but synchronous. 291 292 Returns or throws a [`childProcessResult`](#childProcessResult). 293 294 ### $.sync\`command\` 295 296 Same as [$\`command\`](#command) but synchronous. 297 298 Returns or throws a [`childProcessResult`](#childProcessResult). 299 300 ### execaCommandSync(command, options?) 301 302 Same as [`execaCommand()`](#execacommand-command-options) but synchronous. 303 304 Returns or throws a [`childProcessResult`](#childProcessResult). 305 306 ### Shell syntax 307 308 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. 309 310 ### childProcess 311 312 The return value of all [asynchronous methods](#methods) is both: 313 - a `Promise` resolving or rejecting with a [`childProcessResult`](#childProcessResult). 314 - a [`child_process` instance](https://nodejs.org/api/child_process.html#child_process_class_childprocess) with the following additional methods and properties. 315 316 #### kill(signal?, options?) 317 318 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`. 319 320 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). 321 322 ##### options.forceKillAfterTimeout 323 324 Type: `number | false`\ 325 Default: `5000` 326 327 Milliseconds to wait for the child process to terminate before sending `SIGKILL`. 328 329 Can be disabled with `false`. 330 331 #### all 332 333 Type: `ReadableStream | undefined` 334 335 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). 336 337 This is `undefined` if either: 338 - the [`all` option](#all-2) is `false` (the default value) 339 - 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) 340 341 #### pipeStdout(target) 342 343 [Pipe](https://nodejs.org/api/stream.html#readablepipedestination-options) the child process's `stdout` to `target`, which can be: 344 - Another [`execa()` return value](#pipe-multiple-processes) 345 - A [writable stream](#save-and-pipe-output-from-a-child-process) 346 - A [file path string](#redirect-output-to-a-file) 347 348 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). 349 350 The [`stdout` option](#stdout-1) must be kept as `pipe`, its default value. 351 352 #### pipeStderr(target) 353 354 Like [`pipeStdout()`](#pipestdouttarget) but piping the child process's `stderr` instead. 355 356 The [`stderr` option](#stderr-1) must be kept as `pipe`, its default value. 357 358 #### pipeAll(target) 359 360 Combines both [`pipeStdout()`](#pipestdouttarget) and [`pipeStderr()`](#pipestderrtarget). 361 362 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`. 363 364 ### childProcessResult 365 366 Type: `object` 367 368 Result of a child process execution. On success this is a plain object. On failure this is also an `Error` instance. 369 370 The child process [fails](#failed) when: 371 - its [exit code](#exitcode) is not `0` 372 - it was [killed](#killed) with a [signal](#signal) 373 - [timing out](#timedout) 374 - [being canceled](#iscanceled) 375 - there's not enough memory or there are already too many child processes 376 377 #### command 378 379 Type: `string` 380 381 The file and arguments that were run, for logging purposes. 382 383 This is not escaped and should not be executed directly as a process, including using [`execa()`](#execafile-arguments-options) or [`execaCommand()`](#execacommandcommand-options). 384 385 #### escapedCommand 386 387 Type: `string` 388 389 Same as [`command`](#command-1) but escaped. 390 391 This is meant to be copy and pasted into a shell, for debugging purposes. 392 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). 393 394 #### exitCode 395 396 Type: `number` 397 398 The numeric exit code of the process that was run. 399 400 #### stdout 401 402 Type: `string | Buffer` 403 404 The output of the process on stdout. 405 406 #### stderr 407 408 Type: `string | Buffer` 409 410 The output of the process on stderr. 411 412 #### all 413 414 Type: `string | Buffer | undefined` 415 416 The output of the process with `stdout` and `stderr` interleaved. 417 418 This is `undefined` if either: 419 - the [`all` option](#all-2) is `false` (the default value) 420 - `execaSync()` was used 421 422 #### failed 423 424 Type: `boolean` 425 426 Whether the process failed to run. 427 428 #### timedOut 429 430 Type: `boolean` 431 432 Whether the process timed out. 433 434 #### isCanceled 435 436 Type: `boolean` 437 438 Whether the process was canceled. 439 440 You can cancel the spawned process using the [`signal`](#signal-1) option. 441 442 #### killed 443 444 Type: `boolean` 445 446 Whether the process was killed. 447 448 #### signal 449 450 Type: `string | undefined` 451 452 The name of the signal that was used to terminate the process. For example, `SIGFPE`. 453 454 If a signal terminated the process, this property is defined and included in the error message. Otherwise it is `undefined`. 455 456 #### signalDescription 457 458 Type: `string | undefined` 459 460 A human-friendly description of the signal that was used to terminate the process. For example, `Floating point arithmetic error`. 461 462 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. 463 464 #### cwd 465 466 Type: `string` 467 468 The `cwd` of the command if provided in the [command options](#cwd-1). Otherwise it is `process.cwd()`. 469 470 #### message 471 472 Type: `string` 473 474 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. 475 476 The child process [stderr](#stderr) then [stdout](#stdout) are appended to the end, separated with newlines and not interleaved. 477 478 #### shortMessage 479 480 Type: `string` 481 482 This is the same as the [`message` property](#message) except it does not include the child process stdout/stderr. 483 484 #### originalMessage 485 486 Type: `string | undefined` 487 488 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. 489 490 This is `undefined` unless the child process exited due to an `error` event or a timeout. 491 492 ### options 493 494 Type: `object` 495 496 #### cleanup 497 498 Type: `boolean`\ 499 Default: `true` 500 501 Kill the spawned process when the parent process exits unless either: 502 - the spawned process is [`detached`](https://nodejs.org/api/child_process.html#child_process_options_detached) 503 - the parent process is terminated abruptly, for example, with `SIGKILL` as opposed to `SIGTERM` or a normal exit 504 505 #### preferLocal 506 507 Type: `boolean`\ 508 Default: `true` with [`$`](#command), `false` otherwise 509 510 Prefer locally installed binaries when looking for a binary to execute.\ 511 If you `$ npm install foo`, you can then `execa('foo')`. 512 513 #### localDir 514 515 Type: `string | URL`\ 516 Default: `process.cwd()` 517 518 Preferred path to find locally installed binaries in (use with `preferLocal`). 519 520 #### execPath 521 522 Type: `string`\ 523 Default: `process.execPath` (Current Node.js executable) 524 525 Path to the Node.js executable to use in child processes. 526 527 This can be either an absolute path or a path relative to the [`cwd` option](#cwd). 528 529 Requires [`preferLocal`](#preferlocal) to be `true`. 530 531 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. 532 533 #### buffer 534 535 Type: `boolean`\ 536 Default: `true` 537 538 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. 539 540 If the spawned process fails, [`error.stdout`](#stdout), [`error.stderr`](#stderr), and [`error.all`](#all) will contain the buffered data. 541 542 #### input 543 544 Type: `string | Buffer | stream.Readable` 545 546 Write some input to the `stdin` of your binary.\ 547 Streams are not allowed when using the synchronous methods. 548 549 If the input is a file, use the [`inputFile` option](#inputfile) instead. 550 551 #### inputFile 552 553 Type: `string` 554 555 Use a file as input to the the `stdin` of your binary. 556 557 If the input is not a file, use the [`input` option](#input) instead. 558 559 #### stdin 560 561 Type: `string | number | Stream | undefined`\ 562 Default: `inherit` with [`$`](#command), `pipe` otherwise 563 564 Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio). 565 566 #### stdout 567 568 Type: `string | number | Stream | undefined`\ 569 Default: `pipe` 570 571 Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio). 572 573 #### stderr 574 575 Type: `string | number | Stream | undefined`\ 576 Default: `pipe` 577 578 Same options as [`stdio`](https://nodejs.org/dist/latest-v6.x/docs/api/child_process.html#child_process_options_stdio). 579 580 #### all 581 582 Type: `boolean`\ 583 Default: `false` 584 585 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. 586 587 #### reject 588 589 Type: `boolean`\ 590 Default: `true` 591 592 Setting this to `false` resolves the promise with the error instead of rejecting it. 593 594 #### stripFinalNewline 595 596 Type: `boolean`\ 597 Default: `true` 598 599 Strip the final [newline character](https://en.wikipedia.org/wiki/Newline) from the output. 600 601 #### extendEnv 602 603 Type: `boolean`\ 604 Default: `true` 605 606 Set to `false` if you don't want to extend the environment variables when providing the `env` property. 607 608 --- 609 610 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) 611 612 #### cwd 613 614 Type: `string | URL`\ 615 Default: `process.cwd()` 616 617 Current working directory of the child process. 618 619 #### env 620 621 Type: `object`\ 622 Default: `process.env` 623 624 Environment key-value pairs. Extends automatically from `process.env`. Set [`extendEnv`](#extendenv) to `false` if you don't want this. 625 626 #### argv0 627 628 Type: `string` 629 630 Explicitly set the value of `argv[0]` sent to the child process. This will be set to `file` if not specified. 631 632 #### stdio 633 634 Type: `string | string[]`\ 635 Default: `pipe` 636 637 Child's [stdio](https://nodejs.org/api/child_process.html#child_process_options_stdio) configuration. 638 639 #### serialization 640 641 Type: `string`\ 642 Default: `'json'` 643 644 Specify the kind of serialization used for sending messages between processes when using the [`stdio: 'ipc'`](#stdio) option or [`execaNode()`](#execanodescriptpath-arguments-options): 645 - `json`: Uses `JSON.stringify()` and `JSON.parse()`. 646 - `advanced`: Uses [`v8.serialize()`](https://nodejs.org/api/v8.html#v8_v8_serialize_value) 647 648 [More info.](https://nodejs.org/api/child_process.html#child_process_advanced_serialization) 649 650 #### detached 651 652 Type: `boolean` 653 654 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). 655 656 #### uid 657 658 Type: `number` 659 660 Sets the user identity of the process. 661 662 #### gid 663 664 Type: `number` 665 666 Sets the group identity of the process. 667 668 #### shell 669 670 Type: `boolean | string`\ 671 Default: `false` 672 673 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. 674 675 We recommend against using this option since it is: 676 - not cross-platform, encouraging shell-specific syntax. 677 - slower, because of the additional shell interpretation. 678 - unsafe, potentially allowing command injection. 679 680 #### encoding 681 682 Type: `string | null`\ 683 Default: `utf8` 684 685 Specify the character encoding used to decode the `stdout` and `stderr` output. If set to `null`, then `stdout` and `stderr` will be a `Buffer` instead of a string. 686 687 #### timeout 688 689 Type: `number`\ 690 Default: `0` 691 692 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. 693 694 #### maxBuffer 695 696 Type: `number`\ 697 Default: `100_000_000` (100 MB) 698 699 Largest amount of data in bytes allowed on `stdout` or `stderr`. 700 701 #### killSignal 702 703 Type: `string | number`\ 704 Default: `SIGTERM` 705 706 Signal value to be used when the spawned process will be killed. 707 708 #### signal 709 710 Type: [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal) 711 712 You can abort the spawned process using [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController). 713 714 When `AbortController.abort()` is called, [`.isCanceled`](#iscanceled) becomes `false`. 715 716 *Requires Node.js 16 or later.* 717 718 #### windowsVerbatimArguments 719 720 Type: `boolean`\ 721 Default: `false` 722 723 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`. 724 725 #### windowsHide 726 727 Type: `boolean`\ 728 Default: `true` 729 730 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. 731 732 #### verbose 733 734 Type: `boolean`\ 735 Default: `false` 736 737 [Print each command](#verbose-mode) on `stderr` before executing it. 738 739 This can also be enabled by setting the `NODE_DEBUG=execa` environment variable in the current process. 740 741 #### nodePath *(For `.node()` only)* 742 743 Type: `string`\ 744 Default: [`process.execPath`](https://nodejs.org/api/process.html#process_process_execpath) 745 746 Node.js executable used to create the child process. 747 748 #### nodeOptions *(For `.node()` only)* 749 750 Type: `string[]`\ 751 Default: [`process.execArgv`](https://nodejs.org/api/process.html#process_process_execargv) 752 753 List of [CLI options](https://nodejs.org/api/cli.html#cli_options) passed to the Node.js executable. 754 755 ## Tips 756 757 ### Retry on error 758 759 Gracefully handle failures by using automatic retries and exponential backoff with the [`p-retry`](https://github.com/sindresorhus/p-retry) package: 760 761 ```js 762 import pRetry from 'p-retry'; 763 764 const run = async () => { 765 const results = await execa('curl', ['-sSL', 'https://sindresorhus.com/unicorn']); 766 return results; 767 }; 768 769 console.log(await pRetry(run, {retries: 5})); 770 ``` 771 772 ### Cancelling a spawned process 773 774 ```js 775 import {execa} from 'execa'; 776 777 const abortController = new AbortController(); 778 const subprocess = execa('node', [], {signal: abortController.signal}); 779 780 setTimeout(() => { 781 abortController.abort(); 782 }, 1000); 783 784 try { 785 await subprocess; 786 } catch (error) { 787 console.log(subprocess.killed); // true 788 console.log(error.isCanceled); // true 789 } 790 ``` 791 792 ### Execute the current package's binary 793 794 ```js 795 import {getBinPath} from 'get-bin-path'; 796 797 const binPath = await getBinPath(); 798 await execa(binPath); 799 ``` 800 801 `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. 802 803 ## Related 804 805 - [gulp-execa](https://github.com/ehmicky/gulp-execa) - Gulp plugin for `execa` 806 - [nvexeca](https://github.com/ehmicky/nvexeca) - Run `execa` using any Node.js version 807 - [sudo-prompt](https://github.com/jorangreef/sudo-prompt) - Run commands with elevated privileges. 808 809 ## Maintainers 810 811 - [Sindre Sorhus](https://github.com/sindresorhus) 812 - [@ehmicky](https://github.com/ehmicky) 813 814 --- 815 816 <div align="center"> 817 <b> 818 <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> 819 </b> 820 <br> 821 <sub> 822 Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies. 823 </sub> 824 </div>