Brunobkr/llama.cpp_AlgMor24_github

1# Commander.js2 3[![Build Status](https://github.com/tj/commander.js/workflows/build/badge.svg)](https://github.com/tj/commander.js/actions?query=workflow%3A%22build%22)4[![NPM Version](http://img.shields.io/npm/v/commander.svg?style=flat)](https://www.npmjs.org/package/commander)5[![NPM Downloads](https://img.shields.io/npm/dm/commander.svg?style=flat)](https://npmcharts.com/compare/commander?minimal=true)6[![Install Size](https://packagephobia.now.sh/badge?p=commander)](https://packagephobia.now.sh/result?p=commander)7 8The complete solution for [node.js](http://nodejs.org) command-line interfaces.9 10Read this in other languages: English | [简体中文](./Readme_zh-CN.md)11 12- [Commander.js](#commanderjs)13  - [Installation](#installation)14  - [Declaring _program_ variable](#declaring-program-variable)15  - [Options](#options)16    - [Common option types, boolean and value](#common-option-types-boolean-and-value)17    - [Default option value](#default-option-value)18    - [Other option types, negatable boolean and boolean|value](#other-option-types-negatable-boolean-and-booleanvalue)19    - [Required option](#required-option)20    - [Variadic option](#variadic-option)21    - [Version option](#version-option)22    - [More configuration](#more-configuration)23    - [Custom option processing](#custom-option-processing)24  - [Commands](#commands)25    - [Command-arguments](#command-arguments)26      - [More configuration](#more-configuration-1)27      - [Custom argument processing](#custom-argument-processing)28    - [Action handler](#action-handler)29    - [Stand-alone executable (sub)commands](#stand-alone-executable-subcommands)30    - [Life cycle hooks](#life-cycle-hooks)31  - [Automated help](#automated-help)32    - [Custom help](#custom-help)33    - [Display help after errors](#display-help-after-errors)34    - [Display help from code](#display-help-from-code)35    - [.usage and .name](#usage-and-name)36    - [.helpOption(flags, description)](#helpoptionflags-description)37    - [.addHelpCommand()](#addhelpcommand)38    - [More configuration](#more-configuration-2)39  - [Custom event listeners](#custom-event-listeners)40  - [Bits and pieces](#bits-and-pieces)41    - [.parse() and .parseAsync()](#parse-and-parseasync)42    - [Parsing Configuration](#parsing-configuration)43    - [Legacy options as properties](#legacy-options-as-properties)44    - [TypeScript](#typescript)45    - [createCommand()](#createcommand)46    - [Node options such as `--harmony`](#node-options-such-as---harmony)47    - [Debugging stand-alone executable subcommands](#debugging-stand-alone-executable-subcommands)48    - [Override exit and output handling](#override-exit-and-output-handling)49    - [Additional documentation](#additional-documentation)50  - [Examples](#examples)51  - [Support](#support)52    - [Commander for enterprise](#commander-for-enterprise)53 54For information about terms used in this document see: [terminology](./docs/terminology.md)55 56## Installation57 58```bash59npm install commander60```61 62## Declaring _program_ variable63 64Commander exports a global object which is convenient for quick programs.65This is used in the examples in this README for brevity.66 67```js68const { program } = require('commander');69program.version('0.0.1');70```71 72For larger programs which may use commander in multiple ways, including unit testing, it is better to create a local Command object to use.73 74```js75const { Command } = require('commander');76const program = new Command();77program.version('0.0.1');78```79 80For named imports in ECMAScript modules, import from `commander/esm.mjs`.81 82```js83// index.mjs84import { Command } from 'commander/esm.mjs';85const program = new Command();86```87 88And in TypeScript:89 90```ts91// index.ts92import { Command } from 'commander';93const program = new Command();94```95 96## Options97 98Options are defined with the `.option()` method, also serving as documentation for the options. Each option can have a short flag (single character) and a long name, separated by a comma or space or vertical bar ('|').99 100The parsed options can be accessed by calling `.opts()` on a `Command` object, and are passed to the action handler.101(You can also use `.getOptionValue()` and `.setOptionValue()` to work with a single option value,102and `.getOptionValueSource()` and `.setOptionValueWithSource()` when it matters where the option value came from.)103 104Multi-word options such as "--template-engine" are camel-cased, becoming `program.opts().templateEngine` etc.105 106Multiple short flags may optionally be combined in a single argument following the dash: boolean flags, followed by a single option taking a value (possibly followed by the value).107For example `-a -b -p 80` may be written as `-ab -p80` or even `-abp80`.108 109You can use `--` to indicate the end of the options, and any remaining arguments will be used without being interpreted.110 111By default options on the command line are not positional, and can be specified before or after other arguments.112 113### Common option types, boolean and value114 115The two most used option types are a boolean option, and an option which takes its value116from the following argument (declared with angle brackets like `--expect <value>`). Both are `undefined` unless specified on command line.117 118Example file: [options-common.js](./examples/options-common.js)119 120```js121program122  .option('-d, --debug', 'output extra debugging')123  .option('-s, --small', 'small pizza size')124  .option('-p, --pizza-type <type>', 'flavour of pizza');125 126program.parse(process.argv);127 128const options = program.opts();129if (options.debug) console.log(options);130console.log('pizza details:');131if (options.small) console.log('- small pizza size');132if (options.pizzaType) console.log(`- ${options.pizzaType}`);133```134 135```bash136$ pizza-options -p137error: option '-p, --pizza-type <type>' argument missing138$ pizza-options -d -s -p vegetarian139{ debug: true, small: true, pizzaType: 'vegetarian' }140pizza details:141- small pizza size142- vegetarian143$ pizza-options --pizza-type=cheese144pizza details:145- cheese146```147 148`program.parse(arguments)` processes the arguments, leaving any args not consumed by the program options in the `program.args` array. The parameter is optional and defaults to `process.argv`.149 150### Default option value151 152You can specify a default value for an option which takes a value.153 154Example file: [options-defaults.js](./examples/options-defaults.js)155 156```js157program158  .option('-c, --cheese <type>', 'add the specified type of cheese', 'blue');159 160program.parse();161 162console.log(`cheese: ${program.opts().cheese}`);163```164 165```bash166$ pizza-options167cheese: blue168$ pizza-options --cheese stilton169cheese: stilton170```171 172### Other option types, negatable boolean and boolean|value173 174You can define a boolean option long name with a leading `no-` to set the option value to false when used.175Defined alone this also makes the option true by default.176 177If you define `--foo` first, adding `--no-foo` does not change the default value from what it would178otherwise be. You can specify a default boolean value for a boolean option and it can be overridden on command line.179 180Example file: [options-negatable.js](./examples/options-negatable.js)181 182```js183program184  .option('--no-sauce', 'Remove sauce')185  .option('--cheese <flavour>', 'cheese flavour', 'mozzarella')186  .option('--no-cheese', 'plain with no cheese')187  .parse();188 189const options = program.opts();190const sauceStr = options.sauce ? 'sauce' : 'no sauce';191const cheeseStr = (options.cheese === false) ? 'no cheese' : `${options.cheese} cheese`;192console.log(`You ordered a pizza with ${sauceStr} and ${cheeseStr}`);193```194 195```bash196$ pizza-options197You ordered a pizza with sauce and mozzarella cheese198$ pizza-options --sauce199error: unknown option '--sauce'200$ pizza-options --cheese=blue201You ordered a pizza with sauce and blue cheese202$ pizza-options --no-sauce --no-cheese203You ordered a pizza with no sauce and no cheese204```205 206You can specify an option which may be used as a boolean option but may optionally take an option-argument207(declared with square brackets like `--optional [value]`).208 209Example file: [options-boolean-or-value.js](./examples/options-boolean-or-value.js)210 211```js212program213  .option('-c, --cheese [type]', 'Add cheese with optional type');214 215program.parse(process.argv);216 217const options = program.opts();218if (options.cheese === undefined) console.log('no cheese');219else if (options.cheese === true) console.log('add cheese');220else console.log(`add cheese type ${options.cheese}`);221```222 223```bash224$ pizza-options225no cheese226$ pizza-options --cheese227add cheese228$ pizza-options --cheese mozzarella229add cheese type mozzarella230```231 232For information about possible ambiguous cases, see [options taking varying arguments](./docs/options-taking-varying-arguments.md).233 234### Required option235 236You may specify a required (mandatory) option using `.requiredOption`. The option must have a value after parsing, usually specified on the command line, or perhaps from a default value (say from environment). The method is otherwise the same as `.option` in format, taking flags and description, and optional default value or custom processing.237 238Example file: [options-required.js](./examples/options-required.js)239 240```js241program242  .requiredOption('-c, --cheese <type>', 'pizza must have cheese');243 244program.parse();245```246 247```bash248$ pizza249error: required option '-c, --cheese <type>' not specified250```251 252### Variadic option253 254You may make an option variadic by appending `...` to the value placeholder when declaring the option. On the command line you255can then specify multiple option-arguments, and the parsed option value will be an array. The extra arguments256are read until the first argument starting with a dash. The special argument `--` stops option processing entirely. If a value257is specified in the same argument as the option then no further values are read.258 259Example file: [options-variadic.js](./examples/options-variadic.js)260 261```js262program263  .option('-n, --number <numbers...>', 'specify numbers')264  .option('-l, --letter [letters...]', 'specify letters');265 266program.parse();267 268console.log('Options: ', program.opts());269console.log('Remaining arguments: ', program.args);270```271 272```bash273$ collect -n 1 2 3 --letter a b c274Options:  { number: [ '1', '2', '3' ], letter: [ 'a', 'b', 'c' ] }275Remaining arguments:  []276$ collect --letter=A -n80 operand277Options:  { number: [ '80' ], letter: [ 'A' ] }278Remaining arguments:  [ 'operand' ]279$ collect --letter -n 1 -n 2 3 -- operand280Options:  { number: [ '1', '2', '3' ], letter: true }281Remaining arguments:  [ 'operand' ]282```283 284For information about possible ambiguous cases, see [options taking varying arguments](./docs/options-taking-varying-arguments.md).285 286### Version option287 288The optional `version` method adds handling for displaying the command version. The default option flags are `-V` and `--version`, and when present the command prints the version number and exits.289 290```js291program.version('0.0.1');292```293 294```bash295$ ./examples/pizza -V2960.0.1297```298 299You may change the flags and description by passing additional parameters to the `version` method, using300the same syntax for flags as the `option` method.301 302```js303program.version('0.0.1', '-v, --vers', 'output the current version');304```305 306### More configuration307 308You can add most options using the `.option()` method, but there are some additional features available309by constructing an `Option` explicitly for less common cases.310 311Example files: [options-extra.js](./examples/options-extra.js), [options-env.js](./examples/options-env.js)312 313```js314program315  .addOption(new Option('-s, --secret').hideHelp())316  .addOption(new Option('-t, --timeout <delay>', 'timeout in seconds').default(60, 'one minute'))317  .addOption(new Option('-d, --drink <size>', 'drink size').choices(['small', 'medium', 'large']))318  .addOption(new Option('-p, --port <number>', 'port number').env('PORT'));319```320 321```bash322$ extra --help323Usage: help [options]324 325Options:326  -t, --timeout <delay>  timeout in seconds (default: one minute)327  -d, --drink <size>     drink cup size (choices: "small", "medium", "large")328  -p, --port <number>    port number (env: PORT)329  -h, --help             display help for command330 331$ extra --drink huge332error: option '-d, --drink <size>' argument 'huge' is invalid. Allowed choices are small, medium, large.333 334$ PORT=80 extra 335Options:  { timeout: 60, port: '80' }336```337 338### Custom option processing339 340You may specify a function to do custom processing of option-arguments. The callback function receives two parameters,341the user specified option-argument and the previous value for the option. It returns the new value for the option.342 343This allows you to coerce the option-argument to the desired type, or accumulate values, or do entirely custom processing.344 345You can optionally specify the default/starting value for the option after the function parameter.346 347Example file: [options-custom-processing.js](./examples/options-custom-processing.js)348 349```js350function myParseInt(value, dummyPrevious) {351  // parseInt takes a string and a radix352  const parsedValue = parseInt(value, 10);353  if (isNaN(parsedValue)) {354    throw new commander.InvalidArgumentError('Not a number.');355  }356  return parsedValue;357}358 359function increaseVerbosity(dummyValue, previous) {360  return previous + 1;361}362 363function collect(value, previous) {364  return previous.concat([value]);365}366 367function commaSeparatedList(value, dummyPrevious) {368  return value.split(',');369}370 371program372  .option('-f, --float <number>', 'float argument', parseFloat)373  .option('-i, --integer <number>', 'integer argument', myParseInt)374  .option('-v, --verbose', 'verbosity that can be increased', increaseVerbosity, 0)375  .option('-c, --collect <value>', 'repeatable value', collect, [])376  .option('-l, --list <items>', 'comma separated list', commaSeparatedList)377;378 379program.parse();380 381const options = program.opts();382if (options.float !== undefined) console.log(`float: ${options.float}`);383if (options.integer !== undefined) console.log(`integer: ${options.integer}`);384if (options.verbose > 0) console.log(`verbosity: ${options.verbose}`);385if (options.collect.length > 0) console.log(options.collect);386if (options.list !== undefined) console.log(options.list);387```388 389```bash390$ custom -f 1e2391float: 100392$ custom --integer 2393integer: 2394$ custom -v -v -v395verbose: 3396$ custom -c a -c b -c c397[ 'a', 'b', 'c' ]398$ custom --list x,y,z399[ 'x', 'y', 'z' ]400```401 402## Commands403 404You can specify (sub)commands using `.command()` or `.addCommand()`. There are two ways these can be implemented: using an action handler attached to the command, or as a stand-alone executable file (described in more detail later). The subcommands may be nested ([example](./examples/nestedCommands.js)).405 406In the first parameter to `.command()` you specify the command name. You may append the command-arguments after the command name, or specify them separately using `.argument()`. The arguments may be `<required>` or `[optional]`, and the last argument may also be `variadic...`.407 408You can use `.addCommand()` to add an already configured subcommand to the program.409 410For example:411 412```js413// Command implemented using action handler (description is supplied separately to `.command`)414// Returns new command for configuring.415program416  .command('clone <source> [destination]')417  .description('clone a repository into a newly created directory')418  .action((source, destination) => {419    console.log('clone command called');420  });421 422// Command implemented using stand-alone executable file, indicated by adding description as second parameter to `.command`.423// Returns `this` for adding more commands.424program425  .command('start <service>', 'start named service')426  .command('stop [service]', 'stop named service, or all if no name supplied');427 428// Command prepared separately.429// Returns `this` for adding more commands.430program431  .addCommand(build.makeBuildCommand());432```433 434Configuration options can be passed with the call to `.command()` and `.addCommand()`. Specifying `hidden: true` will435remove the command from the generated help output. Specifying `isDefault: true` will run the subcommand if no other436subcommand is specified ([example](./examples/defaultCommand.js)).437 438### Command-arguments439 440For subcommands, you can specify the argument syntax in the call to `.command()` (as shown above). This441is the only method usable for subcommands implemented using a stand-alone executable, but for other subcommands442you can instead use the following method.443 444To configure a command, you can use `.argument()` to specify each expected command-argument.445You supply the argument name and an optional description. The argument may be `<required>` or `[optional]`.446You can specify a default value for an optional command-argument.447 448Example file: [argument.js](./examples/argument.js)449 450```js451program452  .version('0.1.0')453  .argument('<username>', 'user to login')454  .argument('[password]', 'password for user, if required', 'no password given')455  .action((username, password) => {456    console.log('username:', username);457    console.log('password:', password);458  });459```460 461 The last argument of a command can be variadic, and only the last argument.  To make an argument variadic you462 append `...` to the argument name. A variadic argument is passed to the action handler as an array. For example:463 464```js465program466  .version('0.1.0')467  .command('rmdir')468  .argument('<dirs...>')469  .action(function (dirs) {470    dirs.forEach((dir) => {471      console.log('rmdir %s', dir);472    });473  });474```475 476There is a convenience method to add multiple arguments at once, but without descriptions:477 478```js479program480  .arguments('<username> <password>');481```482 483#### More configuration484 485There are some additional features available by constructing an `Argument` explicitly for less common cases.486 487Example file: [arguments-extra.js](./examples/arguments-extra.js)488 489```js490program491  .addArgument(new commander.Argument('<drink-size>', 'drink cup size').choices(['small', 'medium', 'large']))492  .addArgument(new commander.Argument('[timeout]', 'timeout in seconds').default(60, 'one minute'))493```494 495#### Custom argument processing496 497You may specify a function to do custom processing of command-arguments (like for option-arguments).498The callback function receives two parameters, the user specified command-argument and the previous value for the argument.499It returns the new value for the argument.500 501The processed argument values are passed to the action handler, and saved as `.processedArgs`.502 503You can optionally specify the default/starting value for the argument after the function parameter.504 505Example file: [arguments-custom-processing.js](./examples/arguments-custom-processing.js)506 507```js508program509  .command('add')510  .argument('<first>', 'integer argument', myParseInt)511  .argument('[second]', 'integer argument', myParseInt, 1000)512  .action((first, second) => {513    console.log(`${first} + ${second} = ${first + second}`);514  })515;516```517 518### Action handler519 520The action handler gets passed a parameter for each command-argument you declared, and two additional parameters521which are the parsed options and the command object itself.522 523Example file: [thank.js](./examples/thank.js)524 525```js526program527  .argument('<name>')528  .option('-t, --title <honorific>', 'title to use before name')529  .option('-d, --debug', 'display some debugging')530  .action((name, options, command) => {531    if (options.debug) {532      console.error('Called %s with options %o', command.name(), options);533    }534    const title = options.title ? `${options.title} ` : '';535    console.log(`Thank-you ${title}${name}`);536  });537```538 539You may supply an `async` action handler, in which case you call `.parseAsync` rather than `.parse`.540 541```js542async function run() { /* code goes here */ }543 544async function main() {545  program546    .command('run')547    .action(run);548  await program.parseAsync(process.argv);549}550```551 552A command's options and arguments on the command line are validated when the command is used. Any unknown options or missing arguments will be reported as an error. You can suppress the unknown option checks with `.allowUnknownOption()`. By default it is not an error to553pass more arguments than declared, but you can make this an error with `.allowExcessArguments(false)`.554 555### Stand-alone executable (sub)commands556 557When `.command()` is invoked with a description argument, this tells Commander that you're going to use stand-alone executables for subcommands.558Commander will search the executables in the directory of the entry script (like `./examples/pm`) with the name `program-subcommand`, like `pm-install`, `pm-search`.559You can specify a custom name with the `executableFile` configuration option.560 561You handle the options for an executable (sub)command in the executable, and don't declare them at the top-level.562 563Example file: [pm](./examples/pm)564 565```js566program567  .version('0.1.0')568  .command('install [name]', 'install one or more packages')569  .command('search [query]', 'search with optional query')570  .command('update', 'update installed packages', { executableFile: 'myUpdateSubCommand' })571  .command('list', 'list packages installed', { isDefault: true });572 573program.parse(process.argv);574```575 576If the program is designed to be installed globally, make sure the executables have proper modes, like `755`.577 578### Life cycle hooks579 580You can add callback hooks to a command for life cycle events.581 582Example file: [hook.js](./examples/hook.js)583 584```js585program586  .option('-t, --trace', 'display trace statements for commands')587  .hook('preAction', (thisCommand, actionCommand) => {588    if (thisCommand.opts().trace) {589      console.log(`About to call action handler for subcommand: ${actionCommand.name()}`);590      console.log('arguments: %O', actionCommand.args);591      console.log('options: %o', actionCommand.opts());592    }593  });594```595 596The callback hook can be `async`, in which case you call `.parseAsync` rather than `.parse`. You can add multiple hooks per event.597 598The supported events are:599 600- `preAction`: called before action handler for this command and its subcommands601- `postAction`: called after action handler for this command and its subcommands602 603The hook is passed the command it was added to, and the command running the action handler.604 605## Automated help606 607The help information is auto-generated based on the information commander already knows about your program. The default608help option is `-h,--help`.609 610Example file: [pizza](./examples/pizza)611 612```bash613$ node ./examples/pizza --help614Usage: pizza [options]615 616An application for pizza ordering617 618Options:619  -p, --peppers        Add peppers620  -c, --cheese <type>  Add the specified type of cheese (default: "marble")621  -C, --no-cheese      You do not want any cheese622  -h, --help           display help for command623```624 625A `help` command is added by default if your command has subcommands. It can be used alone, or with a subcommand name to show626further help for the subcommand. These are effectively the same if the `shell` program has implicit help:627 628```bash629shell help630shell --help631 632shell help spawn633shell spawn --help634```635 636### Custom help637 638You can add extra text to be displayed along with the built-in help.639 640Example file: [custom-help](./examples/custom-help)641 642```js643program644  .option('-f, --foo', 'enable some foo');645 646program.addHelpText('after', `647 648Example call:649  $ custom-help --help`);650```651 652Yields the following help output:653 654```Text655Usage: custom-help [options]656 657Options:658  -f, --foo   enable some foo659  -h, --help  display help for command660 661Example call:662  $ custom-help --help663```664 665The positions in order displayed are:666 667- `beforeAll`: add to the program for a global banner or header668- `before`: display extra information before built-in help669- `after`: display extra information after built-in help670- `afterAll`: add to the program for a global footer (epilog)671 672The positions "beforeAll" and "afterAll" apply to the command and all its subcommands.673 674The second parameter can be a string, or a function returning a string. The function is passed a context object for your convenience. The properties are:675 676- error: a boolean for whether the help is being displayed due to a usage error677- command: the Command which is displaying the help678 679### Display help after errors680 681The default behaviour for usage errors is to just display a short error message.682You can change the behaviour to show the full help or a custom help message after an error.683 684```js685program.showHelpAfterError();686// or687program.showHelpAfterError('(add --help for additional information)');688```689 690```sh691$ pizza --unknown692error: unknown option '--unknown'693(add --help for additional information)694```695 696You can also show suggestions after an error for an unknown command or option.697 698```js699program.showSuggestionAfterError();700```701 702```sh703$ pizza --hepl704error: unknown option '--hepl'705(Did you mean --help?)706```707 708### Display help from code709 710`.help()`: display help information and exit immediately. You can optionally pass `{ error: true }` to display on stderr and exit with an error status.711 712`.outputHelp()`: output help information without exiting. You can optionally pass `{ error: true }` to display on stderr.713 714`.helpInformation()`: get the built-in command help information as a string for processing or displaying yourself.715 716### .usage and .name717 718These allow you to customise the usage description in the first line of the help. The name is otherwise719deduced from the (full) program arguments. Given:720 721```js722program723  .name("my-command")724  .usage("[global options] command")725```726 727The help will start with:728 729```Text730Usage: my-command [global options] command731```732 733### .helpOption(flags, description)734 735By default every command has a help option. Override the default help flags and description. Pass false to disable the built-in help option.736 737```js738program739  .helpOption('-e, --HELP', 'read more information');740```741 742### .addHelpCommand()743 744A help command is added by default if your command has subcommands. You can explicitly turn on or off the implicit help command with `.addHelpCommand()` and `.addHelpCommand(false)`.745 746You can both turn on and customise the help command by supplying the name and description:747 748```js749program.addHelpCommand('assist [command]', 'show assistance');750```751 752### More configuration753 754The built-in help is formatted using the Help class.755You can configure the Help behaviour by modifying data properties and methods using `.configureHelp()`, or by subclassing using `.createHelp()` if you prefer.756 757The data properties are:758 759- `helpWidth`: specify the wrap width, useful for unit tests760- `sortSubcommands`: sort the subcommands alphabetically761- `sortOptions`: sort the options alphabetically762 763There are methods getting the visible lists of arguments, options, and subcommands. There are methods for formatting the items in the lists, with each item having a _term_ and _description_. Take a look at `.formatHelp()` to see how they are used.764 765Example file: [configure-help.js](./examples/configure-help.js)766 767```js768program.configureHelp({769  sortSubcommands: true,770  subcommandTerm: (cmd) => cmd.name() // Just show the name, instead of short usage.771});772```773 774## Custom event listeners775 776You can execute custom actions by listening to command and option events.777 778```js779program.on('option:verbose', function () {780  process.env.VERBOSE = this.opts().verbose;781});782```783 784## Bits and pieces785 786### .parse() and .parseAsync()787 788The first argument to `.parse` is the array of strings to parse. You may omit the parameter to implicitly use `process.argv`.789 790If the arguments follow different conventions than node you can pass a `from` option in the second parameter:791 792- 'node': default, `argv[0]` is the application and `argv[1]` is the script being run, with user parameters after that793- 'electron': `argv[1]` varies depending on whether the electron application is packaged794- 'user': all of the arguments from the user795 796For example:797 798```js799program.parse(process.argv); // Explicit, node conventions800program.parse(); // Implicit, and auto-detect electron801program.parse(['-f', 'filename'], { from: 'user' });802```803 804### Parsing Configuration805 806If the default parsing does not suit your needs, there are some behaviours to support other usage patterns.807 808By default program options are recognised before and after subcommands. To only look for program options before subcommands, use `.enablePositionalOptions()`. This lets you use809an option for a different purpose in subcommands.810 811Example file: [positional-options.js](./examples/positional-options.js)812 813With positional options, the `-b` is a program option in the first line and a subcommand option in the second line:814 815```sh816program -b subcommand817program subcommand -b818```819 820By default options are recognised before and after command-arguments. To only process options that come821before the command-arguments, use `.passThroughOptions()`. This lets you pass the  arguments and following options through to another program822without needing to use `--` to end the option processing.823To use pass through options in a subcommand, the program needs to enable positional options.824 825Example file: [pass-through-options.js](./examples/pass-through-options.js)826 827With pass through options, the `--port=80` is a program option in the first line and passed through as a command-argument in the second line:828 829```sh830program --port=80 arg831program arg --port=80832```833 834By default the option processing shows an error for an unknown option. To have an unknown option treated as an ordinary command-argument and continue looking for options, use `.allowUnknownOption()`. This lets you mix known and unknown options.835 836By default the argument processing does not display an error for more command-arguments than expected.837To display an error for excess arguments, use`.allowExcessArguments(false)`.838 839### Legacy options as properties840 841Before Commander 7, the option values were stored as properties on the command.842This was convenient to code but the downside was possible clashes with843existing properties of `Command`. You can revert to the old behaviour to run unmodified legacy code by using `.storeOptionsAsProperties()`.844 845```js846program847  .storeOptionsAsProperties()848  .option('-d, --debug')849  .action((commandAndOptions) => {850    if (commandAndOptions.debug) {851      console.error(`Called ${commandAndOptions.name()}`);852    }853  });854```855 856### TypeScript857 858If you use `ts-node` and  stand-alone executable subcommands written as `.ts` files, you need to call your program through node to get the subcommands called correctly. e.g.859 860```bash861node -r ts-node/register pm.ts862```863 864### createCommand()865 866This factory function creates a new command. It is exported and may be used instead of using `new`, like:867 868```js869const { createCommand } = require('commander');870const program = createCommand();871```872 873`createCommand` is also a method of the Command object, and creates a new command rather than a subcommand. This gets used internally874when creating subcommands using `.command()`, and you may override it to875customise the new subcommand (example file [custom-command-class.js](./examples/custom-command-class.js)).876 877### Node options such as `--harmony`878 879You can enable `--harmony` option in two ways:880 881- Use `#! /usr/bin/env node --harmony` in the subcommands scripts. (Note Windows does not support this pattern.)882- Use the `--harmony` option when call the command, like `node --harmony examples/pm publish`. The `--harmony` option will be preserved when spawning subcommand process.883 884### Debugging stand-alone executable subcommands885 886An executable subcommand is launched as a separate child process.887 888If you are using the node inspector for [debugging](https://nodejs.org/en/docs/guides/debugging-getting-started/) executable subcommands using `node --inspect` et al,889the inspector port is incremented by 1 for the spawned subcommand.890 891If you are using VSCode to debug executable subcommands you need to set the `"autoAttachChildProcesses": true` flag in your launch.json configuration.892 893### Override exit and output handling894 895By default Commander calls `process.exit` when it detects errors, or after displaying the help or version. You can override896this behaviour and optionally supply a callback. The default override throws a `CommanderError`.897 898The override callback is passed a `CommanderError` with properties `exitCode` number, `code` string, and `message`. The default override behaviour is to throw the error, except for async handling of executable subcommand completion which carries on. The normal display of error messages or version or help899is not affected by the override which is called after the display.900 901```js902program.exitOverride();903 904try {905  program.parse(process.argv);906} catch (err) {907  // custom processing...908}909```910 911By default Commander is configured for a command-line application and writes to stdout and stderr.912You can modify this behaviour for custom applications. In addition, you can modify the display of error messages.913 914Example file: [configure-output.js](./examples/configure-output.js)915 916```js917function errorColor(str) {918  // Add ANSI escape codes to display text in red.919  return `\x1b[31m${str}\x1b[0m`;920}921 922program923  .configureOutput({924    // Visibly override write routines as example!925    writeOut: (str) => process.stdout.write(`[OUT] ${str}`),926    writeErr: (str) => process.stdout.write(`[ERR] ${str}`),927    // Highlight errors in color.928    outputError: (str, write) => write(errorColor(str))929  });930```931 932### Additional documentation933 934There is more information available about:935 936- [deprecated](./docs/deprecated.md) features still supported for backwards compatibility937- [options taking varying arguments](./docs/options-taking-varying-arguments.md)938 939## Examples940 941In a single command program, you might not need an action handler.942 943Example file: [pizza](./examples/pizza)944 945```js946const { program } = require('commander');947 948program949  .description('An application for pizza ordering')950  .option('-p, --peppers', 'Add peppers')951  .option('-c, --cheese <type>', 'Add the specified type of cheese', 'marble')952  .option('-C, --no-cheese', 'You do not want any cheese');953 954program.parse();955 956const options = program.opts();957console.log('you ordered a pizza with:');958if (options.peppers) console.log('  - peppers');959const cheese = !options.cheese ? 'no' : options.cheese;960console.log('  - %s cheese', cheese);961```962 963In a multi-command program, you will have action handlers for each command (or stand-alone executables for the commands).964 965Example file: [deploy](./examples/deploy)966 967```js968const { Command } = require('commander');969const program = new Command();970 971program972  .version('0.0.1')973  .option('-c, --config <path>', 'set config path', './deploy.conf');974 975program976  .command('setup [env]')977  .description('run setup commands for all envs')978  .option('-s, --setup_mode <mode>', 'Which setup mode to use', 'normal')979  .action((env, options) => {980    env = env || 'all';981    console.log('read config from %s', program.opts().config);982    console.log('setup for %s env(s) with %s mode', env, options.setup_mode);983  });984 985program986  .command('exec <script>')987  .alias('ex')988  .description('execute the given remote cmd')989  .option('-e, --exec_mode <mode>', 'Which exec mode to use', 'fast')990  .action((script, options) => {991    console.log('read config from %s', program.opts().config);992    console.log('exec "%s" using %s mode and config %s', script, options.exec_mode, program.opts().config);993  }).addHelpText('after', `994Examples:995  $ deploy exec sequential996  $ deploy exec async`997  );998 999program.parse(process.argv);1000```1001 1002More samples can be found in the [examples](https://github.com/tj/commander.js/tree/master/examples) directory.1003 1004## Support1005 1006The current version of Commander is fully supported on Long Term Support versions of node, and requires at least node v12.1007(For older versions of node, use an older version of Commander. Commander version 2.x has the widest support.)1008 1009The main forum for free and community support is the project [Issues](https://github.com/tj/commander.js/issues) on GitHub.1010 1011### Commander for enterprise1012 1013Available as part of the Tidelift Subscription1014 1015The maintainers of Commander and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. [Learn more.](https://tidelift.com/subscription/pkg/npm-commander?utm_source=npm-commander&utm_medium=referral&utm_campaign=enterprise&utm_term=repo)1016