You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1244 lines
31 KiB
1244 lines
31 KiB
yargs
|
|
========
|
|
|
|
Yargs be a node.js library fer hearties tryin' ter parse optstrings.
|
|
|
|
With yargs, ye be havin' a map that leads straight to yer treasure! Treasure of course, being a simple option hash.
|
|
|
|
[![Build Status][travis-image]][travis-url]
|
|
[![Dependency Status][gemnasium-image]][gemnasium-url]
|
|
[![Coverage Status][coveralls-image]][coveralls-url]
|
|
[![NPM version][npm-image]][npm-url]
|
|
[![Windows Tests][windows-image]][windows-url]
|
|
|
|
> Yargs is the official successor to optimist. Please feel free to submit issues and pull requests. If you'd like to contribute and don't know where to start, have a look at [the issue list](https://github.com/bcoe/yargs/issues) :)
|
|
|
|
examples
|
|
========
|
|
|
|
With yargs, the options be just a hash!
|
|
-------------------------------------------------------------------
|
|
|
|
plunder.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs').argv;
|
|
|
|
if (argv.ships > 3 && argv.distance < 53.5) {
|
|
console.log('Plunder more riffiwobbles!');
|
|
}
|
|
else {
|
|
console.log('Retreat from the xupptumblers!');
|
|
}
|
|
````
|
|
|
|
***
|
|
|
|
$ ./plunder.js --ships=4 --distance=22
|
|
Plunder more riffiwobbles!
|
|
|
|
$ ./plunder.js --ships 12 --distance 98.7
|
|
Retreat from the xupptumblers!
|
|
|
|
|
|
|
|
But don't walk the plank just yet! There be more! You can do short options:
|
|
-------------------------------------------------
|
|
|
|
short.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs').argv;
|
|
console.log('(%d,%d)', argv.x, argv.y);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./short.js -x 10 -y 21
|
|
(10,21)
|
|
|
|
And booleans, both long, short, and even grouped:
|
|
----------------------------------
|
|
|
|
bool.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs').argv;
|
|
|
|
if (argv.s) {
|
|
process.stdout.write(argv.fr ? 'Le perroquet dit: ' : 'The parrot says: ');
|
|
}
|
|
console.log(
|
|
(argv.fr ? 'couac' : 'squawk') + (argv.p ? '!' : '')
|
|
);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./bool.js -s
|
|
The parrot says: squawk
|
|
|
|
$ ./bool.js -sp
|
|
The parrot says: squawk!
|
|
|
|
$ ./bool.js -sp --fr
|
|
Le perroquet dit: couac!
|
|
|
|
And non-hyphenated options too! Just use `argv._`!
|
|
-------------------------------------------------
|
|
|
|
nonopt.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs').argv;
|
|
console.log('(%d,%d)', argv.x, argv.y);
|
|
console.log(argv._);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./nonopt.js -x 6.82 -y 3.35 rum
|
|
(6.82,3.35)
|
|
[ 'rum' ]
|
|
|
|
$ ./nonopt.js "me hearties" -x 0.54 yo -y 1.12 ho
|
|
(0.54,1.12)
|
|
[ 'me hearties', 'yo', 'ho' ]
|
|
|
|
Yargs even counts your booleans!
|
|
----------------------------------------------------------------------
|
|
|
|
count.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.count('verbose')
|
|
.alias('v', 'verbose')
|
|
.argv;
|
|
|
|
VERBOSE_LEVEL = argv.verbose;
|
|
|
|
function WARN() { VERBOSE_LEVEL >= 0 && console.log.apply(console, arguments); }
|
|
function INFO() { VERBOSE_LEVEL >= 1 && console.log.apply(console, arguments); }
|
|
function DEBUG() { VERBOSE_LEVEL >= 2 && console.log.apply(console, arguments); }
|
|
|
|
WARN("Showing only important stuff");
|
|
INFO("Showing semi-important stuff too");
|
|
DEBUG("Extra chatty mode");
|
|
````
|
|
|
|
***
|
|
$ node count.js
|
|
Showing only important stuff
|
|
|
|
$ node count.js -v
|
|
Showing only important stuff
|
|
Showing semi-important stuff too
|
|
|
|
$ node count.js -vv
|
|
Showing only important stuff
|
|
Showing semi-important stuff too
|
|
Extra chatty mode
|
|
|
|
$ node count.js -v --verbose
|
|
Showing only important stuff
|
|
Showing semi-important stuff too
|
|
Extra chatty mode
|
|
|
|
Tell users how to use yer options and make demands.
|
|
-------------------------------------------------
|
|
|
|
area.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.usage('Usage: $0 -w [num] -h [num]')
|
|
.demand(['w','h'])
|
|
.argv;
|
|
|
|
console.log("The area is:", argv.w * argv.h);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./area.js -w 55 -h 11
|
|
The area is: 605
|
|
|
|
$ node ./area.js -w 4.91 -w 2.51
|
|
Usage: area.js -w [num] -h [num]
|
|
|
|
Options:
|
|
-w [required]
|
|
-h [required]
|
|
|
|
Missing required arguments: h
|
|
|
|
After yer demands have been met, demand more! Ask for non-hyphenated arguments!
|
|
-----------------------------------------
|
|
|
|
demand_count.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.demand(2)
|
|
.argv;
|
|
console.dir(argv);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./demand_count.js a
|
|
|
|
Not enough non-option arguments: got 1, need at least 2
|
|
|
|
$ ./demand_count.js a b
|
|
{ _: [ 'a', 'b' ], '$0': 'demand_count.js' }
|
|
|
|
$ ./demand_count.js a b c
|
|
{ _: [ 'a', 'b', 'c' ], '$0': 'demand_count.js' }
|
|
|
|
EVEN MORE SHIVER ME TIMBERS!
|
|
------------------
|
|
|
|
default_singles.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.default('x', 10)
|
|
.default('y', 10)
|
|
.argv
|
|
;
|
|
console.log(argv.x + argv.y);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./default_singles.js -x 5
|
|
15
|
|
|
|
default_hash.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.default({ x : 10, y : 10 })
|
|
.argv
|
|
;
|
|
console.log(argv.x + argv.y);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./default_hash.js -y 7
|
|
17
|
|
|
|
And if you really want to get all descriptive about it...
|
|
---------------------------------------------------------
|
|
|
|
boolean_single.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.boolean('v')
|
|
.argv
|
|
;
|
|
console.dir(argv.v);
|
|
console.dir(argv._);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./boolean_single.js -v "me hearties" yo ho
|
|
true
|
|
[ 'me hearties', 'yo', 'ho' ]
|
|
|
|
|
|
boolean_double.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.boolean(['x','y','z'])
|
|
.argv
|
|
;
|
|
console.dir([ argv.x, argv.y, argv.z ]);
|
|
console.dir(argv._);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./boolean_double.js -x -z one two three
|
|
[ true, false, true ]
|
|
[ 'one', 'two', 'three' ]
|
|
|
|
Yargs is here to help you...
|
|
---------------------------
|
|
|
|
Ye can describe parameters fer help messages and set aliases. Yargs figures
|
|
out how ter format a handy help string automatically.
|
|
|
|
line_count.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.usage('Usage: $0 <command> [options]')
|
|
.command('count', 'Count the lines in a file')
|
|
.demand(1)
|
|
.example('$0 count -f foo.js', 'count the lines in the given file')
|
|
.demand('f')
|
|
.alias('f', 'file')
|
|
.nargs('f', 1)
|
|
.describe('f', 'Load a file')
|
|
.help('h')
|
|
.alias('h', 'help')
|
|
.epilog('copyright 2015')
|
|
.argv;
|
|
|
|
var fs = require('fs');
|
|
var s = fs.createReadStream(argv.file);
|
|
|
|
var lines = 0;
|
|
s.on('data', function (buf) {
|
|
lines += buf.toString().match(/\n/g).length;
|
|
});
|
|
|
|
s.on('end', function () {
|
|
console.log(lines);
|
|
});
|
|
````
|
|
|
|
***
|
|
$ node line_count.js count
|
|
Usage: line_count.js <command> [options]
|
|
|
|
Commands:
|
|
count Count the lines in a file
|
|
|
|
Options:
|
|
-f, --file Load a file [required]
|
|
-h, --help Show help [boolean]
|
|
|
|
Examples:
|
|
line_count.js count -f foo.js count the lines in the given file
|
|
|
|
copyright 2015
|
|
|
|
Missing required arguments: f
|
|
|
|
$ node line_count.js count --file line_count.js
|
|
26
|
|
|
|
$ node line_count.js count -f line_count.js
|
|
26
|
|
|
|
methods
|
|
=======
|
|
|
|
By itself,
|
|
|
|
````javascript
|
|
require('yargs').argv
|
|
````
|
|
|
|
will use the `process.argv` array to construct the `argv` object.
|
|
|
|
You can pass in the `process.argv` yourself:
|
|
|
|
````javascript
|
|
require('yargs')([ '-x', '1', '-y', '2' ]).argv
|
|
````
|
|
|
|
or use `.parse()` to do the same thing:
|
|
|
|
````javascript
|
|
require('yargs').parse([ '-x', '1', '-y', '2' ])
|
|
````
|
|
|
|
The rest of these methods below come in just before the terminating `.argv`.
|
|
|
|
<a name="alias"></a>.alias(key, alias)
|
|
------------------
|
|
|
|
Set key names as equivalent such that updates to a key will propagate to aliases
|
|
and vice-versa.
|
|
|
|
Optionally `.alias()` can take an object that maps keys to aliases.
|
|
Each key of this object should be the canonical version of the option, and each
|
|
value should be a string or an array of strings.
|
|
|
|
.argv
|
|
-----
|
|
|
|
Get the arguments as a plain old object.
|
|
|
|
Arguments without a corresponding flag show up in the `argv._` array.
|
|
|
|
The script name or node command is available at `argv.$0` similarly to how `$0`
|
|
works in bash or perl.
|
|
|
|
If `yargs` is executed in an environment that embeds node and there's no script name (e.g.
|
|
[Electron](http://electron.atom.io/) or [nw.js](http://nwjs.io/)), it will ignore the first parameter since it
|
|
expects it to be the script name. In order to override this behavior, use `.parse(process.argv.slice(1))`
|
|
instead of `.argv` and the first parameter won't be ignored.
|
|
|
|
<a name="array"></a>.array(key)
|
|
----------
|
|
|
|
Tell the parser to interpret `key` as an array. If `.array('foo')` is set,
|
|
`--foo foo bar` will be parsed as `['foo', 'bar']` rather than as `'foo'`.
|
|
|
|
<a name="boolean"></a>.boolean(key)
|
|
-------------
|
|
|
|
Interpret `key` as a boolean. If a non-flag option follows `key` in
|
|
`process.argv`, that string won't get set as the value of `key`.
|
|
|
|
`key` will default to `false`, unless a `default(key, undefined)` is
|
|
explicitly set.
|
|
|
|
If `key` is an array, interpret all the elements as booleans.
|
|
|
|
.check(fn)
|
|
----------
|
|
|
|
Check that certain conditions are met in the provided arguments.
|
|
|
|
`fn` is called with two arguments, the parsed `argv` hash and an array of options and their aliases.
|
|
|
|
If `fn` throws or returns a non-truthy value, show the thrown error, usage information, and
|
|
exit.
|
|
|
|
<a name="choices"></a>.choices(key, choices)
|
|
----------------------
|
|
|
|
Limit valid values for `key` to a predefined set of `choices`, given as an array
|
|
or as an individual value.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.alias('i', 'ingredient')
|
|
.describe('i', 'choose your sandwich ingredients')
|
|
.choices('i', ['peanut-butter', 'jelly', 'banana', 'pickles'])
|
|
.help('help')
|
|
.argv
|
|
```
|
|
|
|
If this method is called multiple times, all enumerated values will be merged
|
|
together. Choices are generally strings or numbers, and value matching is
|
|
case-sensitive.
|
|
|
|
Optionally `.choices()` can take an object that maps multiple keys to their
|
|
choices.
|
|
|
|
Choices can also be specified as `choices` in the object given to `option()`.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.option('size', {
|
|
alias: 's',
|
|
describe: 'choose a size',
|
|
choices: ['xs', 's', 'm', 'l', 'xl']
|
|
})
|
|
.argv
|
|
```
|
|
|
|
.command(cmd, desc, [fn])
|
|
-------------------
|
|
|
|
Document the commands exposed by your application.
|
|
|
|
Use `desc` to provide a description for each command your application accepts (the
|
|
values stored in `argv._`). Set `desc` to `false` to create a hidden command.
|
|
Hidden commands don't show up in the help output and aren't available for
|
|
completion.
|
|
|
|
Optionally, you can provide a handler `fn` which will be executed when
|
|
a given command is provided. The handler will be called with `yargs` and
|
|
`argv` as arguments.
|
|
|
|
`yargs` is a blank instance of yargs, which can be used to compose a nested
|
|
hierarchy of options handlers.
|
|
|
|
`argv` represents the arguments parsed prior to the
|
|
command being executed (those described in the outer yargs instance).
|
|
|
|
Here's an example of top-level and nested commands in action:
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.usage('npm <command>')
|
|
.command('install', 'tis a mighty fine package to install')
|
|
.command('publish', 'shiver me timbers, should you be sharing all that', function (yargs, argv) {
|
|
argv = yargs.option('f', {
|
|
alias: 'force',
|
|
description: 'yar, it usually be a bad idea'
|
|
})
|
|
.help('help')
|
|
.argv
|
|
})
|
|
.help('help')
|
|
.argv;
|
|
```
|
|
|
|
.completion(cmd, [description], [fn]);
|
|
-------------
|
|
|
|
Enable bash-completion shortcuts for commands and options.
|
|
|
|
`cmd`: When present in `argv._`, will result in the `.bashrc` completion script
|
|
being outputted. To enable bash completions, concat the generated script to your
|
|
`.bashrc` or `.bash_profile`.
|
|
|
|
`description`: Provide a description in your usage instructions for the command
|
|
that generates bash completion scripts.
|
|
|
|
`fn`: Rather than relying on yargs' default completion functionality, which
|
|
shiver me timbers is pretty awesome, you can provide your own completion
|
|
method.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.completion('completion', function(current, argv) {
|
|
// 'current' is the current command being completed.
|
|
// 'argv' is the parsed arguments so far.
|
|
// simply return an array of completions.
|
|
return [
|
|
'foo',
|
|
'bar'
|
|
];
|
|
})
|
|
.argv;
|
|
```
|
|
|
|
You can also provide asynchronous completions.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.completion('completion', function(current, argv, done) {
|
|
setTimeout(function() {
|
|
done([
|
|
'apple',
|
|
'banana'
|
|
]);
|
|
}, 500);
|
|
})
|
|
.argv;
|
|
```
|
|
|
|
But wait, there's more! You can return an asynchronous promise.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.completion('completion', function(current, argv, done) {
|
|
return new Promise(function (resolve, reject) {
|
|
setTimeout(function () {
|
|
resolve(['apple', 'banana'])
|
|
}, 10)
|
|
})
|
|
})
|
|
.argv;
|
|
```
|
|
|
|
<a name="config"></a>.config(key, [description], [parseFn])
|
|
------------
|
|
|
|
Tells the parser that if the option specified by `key` is passed in, it
|
|
should be interpreted as a path to a JSON config file. The file is loaded
|
|
and parsed, and its properties are set as arguments.
|
|
|
|
An optional `description` can be provided to customize the config (`key`) option
|
|
in the usage string.
|
|
|
|
An optional `parseFn` can be used to provide a custom parser. The parsing
|
|
function must be synchronous, and should return an object containing
|
|
key value pairs or an error.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.config('settings', function (configPath) {
|
|
return JSON.parse(fs.readFileSync(configPath, 'utf-8'))
|
|
})
|
|
.argv
|
|
```
|
|
|
|
<a name="count"></a>.count(key)
|
|
------------
|
|
|
|
Interpret `key` as a boolean flag, but set its parsed value to the number of
|
|
flag occurrences rather than `true` or `false`. Default value is thus `0`.
|
|
|
|
<a name="default"></a>.default(key, value, [description])
|
|
--------------------
|
|
|
|
Set `argv[key]` to `value` if no option was specified in `process.argv`.
|
|
|
|
Optionally `.default()` can take an object that maps keys to default values.
|
|
|
|
But wait, there's more! The default value can be a `function` which returns
|
|
a value. The name of the function will be used in the usage string:
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.default('random', function randomValue() {
|
|
return Math.random() * 256;
|
|
}).argv;
|
|
```
|
|
|
|
Optionally, `description` can also be provided and will take precedence over
|
|
displaying the value in the usage instructions:
|
|
|
|
```js
|
|
.default('timeout', 60000, '(one-minute)')
|
|
```
|
|
|
|
<a name="demand"></a>.demand(key, [msg | boolean])
|
|
------------------------------
|
|
.demand(count, [max], [msg])
|
|
------------------------------
|
|
|
|
If `key` is a string, show the usage information and exit if `key` wasn't
|
|
specified in `process.argv`.
|
|
|
|
If `key` is a number, demand at least as many non-option arguments, which show
|
|
up in `argv._`. A second number can also optionally be provided, which indicates
|
|
the maximum number of non-option arguments.
|
|
|
|
If `key` is an array, demand each element.
|
|
|
|
If a `msg` string is given, it will be printed when the argument is missing,
|
|
instead of the standard error message. This is especially helpful for the non-option arguments in `argv._`.
|
|
|
|
If a `boolean` value is given, it controls whether the option is demanded;
|
|
this is useful when using `.options()` to specify command line parameters.
|
|
|
|
<a name="describe"></a>.describe(key, desc)
|
|
--------------------
|
|
|
|
Describe a `key` for the generated usage information.
|
|
|
|
Optionally `.describe()` can take an object that maps keys to descriptions.
|
|
|
|
.detectLocale(boolean)
|
|
-----------
|
|
|
|
Should yargs attempt to detect the os' locale? Defaults to `true`.
|
|
|
|
.env([prefix])
|
|
--------------
|
|
|
|
Tell yargs to parse environment variables matching the given prefix and apply
|
|
them to argv as though they were command line arguments.
|
|
|
|
If this method is called with no argument or with an empty string or with `true`,
|
|
then all env vars will be applied to argv.
|
|
|
|
Program arguments are defined in this order of precedence:
|
|
|
|
1. Command line args
|
|
2. Config file
|
|
3. Env var
|
|
4. Configured defaults
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.env('MY_PROGRAM')
|
|
.option('f', {
|
|
alias: 'fruit-thing',
|
|
default: 'apple'
|
|
})
|
|
.argv
|
|
console.log(argv)
|
|
```
|
|
|
|
```
|
|
$ node fruity.js
|
|
{ _: [],
|
|
f: 'apple',
|
|
'fruit-thing': 'apple',
|
|
fruitThing: 'apple',
|
|
'$0': 'fruity.js' }
|
|
```
|
|
|
|
```
|
|
$ MY_PROGRAM_FRUIT_THING=banana node fruity.js
|
|
{ _: [],
|
|
fruitThing: 'banana',
|
|
f: 'banana',
|
|
'fruit-thing': 'banana',
|
|
'$0': 'fruity.js' }
|
|
```
|
|
|
|
```
|
|
$ MY_PROGRAM_FRUIT_THING=banana node fruity.js -f cat
|
|
{ _: [],
|
|
f: 'cat',
|
|
'fruit-thing': 'cat',
|
|
fruitThing: 'cat',
|
|
'$0': 'fruity.js' }
|
|
```
|
|
|
|
Env var parsing is disabled by default, but you can also explicitly disable it
|
|
by calling `.env(false)`, e.g. if you need to undo previous configuration.
|
|
|
|
.epilog(str)
|
|
------------
|
|
.epilogue(str)
|
|
--------------
|
|
|
|
A message to print at the end of the usage instructions, e.g.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.epilogue('for more information, find our manual at http://example.com');
|
|
```
|
|
|
|
.example(cmd, desc)
|
|
-------------------
|
|
|
|
Give some example invocations of your program. Inside `cmd`, the string
|
|
`$0` will get interpolated to the current script name or node command for the
|
|
present script similar to how `$0` works in bash or perl.
|
|
Examples will be printed out as part of the help message.
|
|
|
|
.exitProcess(enable)
|
|
----------------------------------
|
|
|
|
By default, yargs exits the process when the user passes a help flag, uses the
|
|
`.version` functionality, or when validation fails. Calling
|
|
`.exitProcess(false)` disables this behavior, enabling further actions after
|
|
yargs have been validated.
|
|
|
|
.fail(fn)
|
|
---------
|
|
|
|
Method to execute when a failure occurs, rather than printing the failure message.
|
|
|
|
`fn` is called with the failure message that would have been printed.
|
|
|
|
<a name="group"></a>.group(key(s), groupName)
|
|
--------------------
|
|
|
|
Given a key, or an array of keys, places options under an alternative heading
|
|
when displaying usage instructions, e.g.,
|
|
|
|
```js
|
|
var yargs = require('yargs')(['--help'])
|
|
.help('help')
|
|
.group('batman', 'Heroes:')
|
|
.describe('batman', "world's greatest detective")
|
|
.wrap(null)
|
|
.argv
|
|
```
|
|
***
|
|
Heroes:
|
|
--batman world's greatest detective
|
|
|
|
Options:
|
|
--help Show help [boolean]
|
|
|
|
.help([option, [description]])
|
|
------------------------------
|
|
|
|
Add an option (e.g. `--help`) that displays the usage string and exits the
|
|
process. If present, the `description` parameter customizes the description of
|
|
the help option in the usage string.
|
|
|
|
If invoked without parameters, `.help()` returns the generated usage string.
|
|
|
|
Example:
|
|
|
|
```js
|
|
var yargs = require("yargs")
|
|
.usage("$0 -operand1 number -operand2 number -operation [add|subtract]");
|
|
console.log(yargs.help());
|
|
```
|
|
|
|
Later on, `argv` can be retrieved with `yargs.argv`.
|
|
|
|
.implies(x, y)
|
|
--------------
|
|
|
|
Given the key `x` is set, it is required that the key `y` is set.
|
|
|
|
Optionally `.implies()` can accept an object specifying multiple implications.
|
|
|
|
.locale()
|
|
---------
|
|
|
|
Return the locale that yargs is currently using.
|
|
|
|
By default, yargs will auto-detect the operating system's locale so that
|
|
yargs-generated help content will display in the user's language.
|
|
|
|
To override this behavior with a static locale, pass the desired locale as a
|
|
string to this method (see below).
|
|
|
|
.locale(locale)
|
|
---------------
|
|
|
|
Override the auto-detected locale from the user's operating system with a static
|
|
locale. Note that the OS locale can be modified by setting/exporting the `LC_ALL`
|
|
environment variable.
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.usage('./$0 - follow ye instructions true')
|
|
.option('option', {
|
|
alias: 'o',
|
|
describe: "'tis a mighty fine option",
|
|
demand: true
|
|
})
|
|
.command('run', "Arrr, ya best be knowin' what yer doin'")
|
|
.example('$0 run foo', "shiver me timbers, here's an example for ye")
|
|
.help('help')
|
|
.wrap(70)
|
|
.locale('pirate')
|
|
.argv
|
|
```
|
|
|
|
***
|
|
|
|
```shell
|
|
./test.js - follow ye instructions true
|
|
|
|
Choose yer command:
|
|
run Arrr, ya best be knowin' what yer doin'
|
|
|
|
Options for me hearties!
|
|
--option, -o 'tis a mighty fine option [requi-yar-ed]
|
|
--help Parlay this here code of conduct [boolean]
|
|
|
|
Ex. marks the spot:
|
|
test.js run foo shiver me timbers, here's an example for ye
|
|
|
|
Ye be havin' to set the followin' argument land lubber: option
|
|
```
|
|
|
|
Locales currently supported:
|
|
|
|
* **de:** German.
|
|
* **en:** American English.
|
|
* **es:** Spanish.
|
|
* **fr:** French.
|
|
* **id:** Indonesian.
|
|
* **ja:** Japanese.
|
|
* **ko:** Korean.
|
|
* **nb:** Norwegian Bokmål.
|
|
* **pirate:** American Pirate.
|
|
* **pt:** Portuguese.
|
|
* **pt_BR:** Brazilian Portuguese.
|
|
* **tr:** Turkish.
|
|
* **zh:** Chinese.
|
|
|
|
To submit a new translation for yargs:
|
|
|
|
1. use `./locales/en.json` as a starting point.
|
|
2. submit a pull request with the new locale file.
|
|
|
|
*The [Microsoft Terminology Search](http://www.microsoft.com/Language/en-US/Search.aspx) can be useful for finding the correct terminology in your locale.*
|
|
|
|
<a name="nargs"></a>.nargs(key, count)
|
|
-----------
|
|
|
|
The number of arguments that should be consumed after a key. This can be a
|
|
useful hint to prevent parsing ambiguity. For example:
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.nargs('token', 1)
|
|
.parse(['--token', '-my-token']);
|
|
```
|
|
|
|
parses as:
|
|
|
|
`{ _: [], token: '-my-token', '$0': 'node test' }`
|
|
|
|
Optionally `.nargs()` can take an object of `key`/`narg` pairs.
|
|
|
|
.option(key, opt)
|
|
-----------------
|
|
.options(key, opt)
|
|
------------------
|
|
|
|
Instead of chaining together `.alias().demand().default().describe().string()`, you can specify
|
|
keys in `opt` for each of the chainable methods.
|
|
|
|
For example:
|
|
|
|
````javascript
|
|
var argv = require('yargs')
|
|
.option('f', {
|
|
alias: 'file',
|
|
demand: true,
|
|
default: '/etc/passwd',
|
|
describe: 'x marks the spot',
|
|
type: 'string'
|
|
})
|
|
.argv
|
|
;
|
|
````
|
|
|
|
is the same as
|
|
|
|
````javascript
|
|
var argv = require('yargs')
|
|
.alias('f', 'file')
|
|
.demand('f')
|
|
.default('f', '/etc/passwd')
|
|
.describe('f', 'x marks the spot')
|
|
.string('f')
|
|
.argv
|
|
;
|
|
````
|
|
|
|
Optionally `.options()` can take an object that maps keys to `opt` parameters.
|
|
|
|
````javascript
|
|
var argv = require('yargs')
|
|
.options({
|
|
'f': {
|
|
alias: 'file',
|
|
demand: true,
|
|
default: '/etc/passwd',
|
|
describe: 'x marks the spot',
|
|
type: 'string'
|
|
}
|
|
})
|
|
.argv
|
|
;
|
|
````
|
|
|
|
Valid `opt` keys include:
|
|
|
|
- `alias`: string or array of strings, alias(es) for the canonical option key, see [`alias()`](#alias)
|
|
- `array`: boolean, interpret option as an array, see [`array()`](#array)
|
|
- `boolean`: boolean, interpret option as a boolean flag, see [`boolean()`](#boolean)
|
|
- `choices`: value or array of values, limit valid option arguments to a predefined set, see [`choices()`](#choices)
|
|
- `config`: boolean, interpret option as a path to a JSON config file, see [`config()`](#config)
|
|
- `configParser`: function, provide a custom config parsing function, see [`config()`](#config)
|
|
- `count`: boolean, interpret option as a count of boolean flags, see [`count()`](#count)
|
|
- `default`: value, set a default value for the option, see [`default()`](#default)
|
|
- `defaultDescription`: string, use this description for the default value in help content, see [`default()`](#default)
|
|
- `demand`/`require`/`required`: boolean or string, demand the option be given, with optional error message, see [`demand()`](#demand)
|
|
- `desc`/`describe`/`description`: string, the option description for help content, see [`describe()`](#describe)
|
|
- `group`: string, when displaying usage instructions place the option under an alternative group heading, see [`group()`](#group)
|
|
- `nargs`: number, specify how many arguments should be consumed for the option, see [`nargs()`](#nargs)
|
|
- `requiresArg`: boolean, require the option be specified with a value, see [`requiresArg()`](#requiresArg)
|
|
- `string`: boolean, interpret option as a string, see [`string()`](#string)
|
|
- `type`: one of the following strings
|
|
- `'array'`: synonymous for `array: true`, see [`array()`](#array)
|
|
- `'boolean'`: synonymous for `boolean: true`, see [`boolean()`](#boolean)
|
|
- `'count'`: synonymous for `count: true`, see [`count()`](#count)
|
|
- `'string'`: synonymous for `string: true`, see [`string()`](#string)
|
|
|
|
.parse(args)
|
|
------------
|
|
|
|
Parse `args` instead of `process.argv`. Returns the `argv` object.
|
|
|
|
`args` may either be a pre-processed argv array, or a raw argument string.
|
|
|
|
.require(key, [msg | boolean])
|
|
------------------------------
|
|
.required(key, [msg | boolean])
|
|
------------------------------
|
|
|
|
An alias for [`demand()`](#demand). See docs there.
|
|
|
|
<a name="requiresArg"></a>.requiresArg(key)
|
|
-----------------
|
|
|
|
Specifies either a single option key (string), or an array of options that
|
|
must be followed by option values. If any option value is missing, show the
|
|
usage information and exit.
|
|
|
|
The default behavior is to set the value of any key not followed by an
|
|
option value to `true`.
|
|
|
|
.reset()
|
|
--------
|
|
|
|
Reset the argument object built up so far. This is useful for
|
|
creating nested command line interfaces.
|
|
|
|
```js
|
|
var yargs = require('yargs')
|
|
.usage('$0 command')
|
|
.command('hello', 'hello command')
|
|
.command('world', 'world command')
|
|
.demand(1, 'must provide a valid command'),
|
|
argv = yargs.argv,
|
|
command = argv._[0];
|
|
|
|
if (command === 'hello') {
|
|
yargs.reset()
|
|
.usage('$0 hello')
|
|
.help('h')
|
|
.example('$0 hello', 'print the hello message!')
|
|
.argv
|
|
|
|
console.log('hello!');
|
|
} else if (command === 'world'){
|
|
yargs.reset()
|
|
.usage('$0 world')
|
|
.help('h')
|
|
.example('$0 world', 'print the world message!')
|
|
.argv
|
|
|
|
console.log('world!');
|
|
} else {
|
|
yargs.showHelp();
|
|
}
|
|
```
|
|
|
|
.showCompletionScript()
|
|
----------------------
|
|
|
|
Generate a bash completion script. Users of your application can install this
|
|
script in their `.bashrc`, and yargs will provide completion shortcuts for
|
|
commands and options.
|
|
|
|
.showHelp(consoleLevel='error')
|
|
---------------------------
|
|
|
|
Print the usage data using the [`console`](https://nodejs.org/api/console.html) function `consoleLevel` for printing.
|
|
|
|
Example:
|
|
|
|
```js
|
|
var yargs = require("yargs")
|
|
.usage("$0 -operand1 number -operand2 number -operation [add|subtract]");
|
|
yargs.showHelp(); //prints to stderr using console.error()
|
|
```
|
|
|
|
Or, to print the usage data to `stdout` instead, you can specify the use of `console.log`:
|
|
|
|
```js
|
|
yargs.showHelp("log"); //prints to stdout using console.log()
|
|
```
|
|
|
|
Later on, `argv` can be retrieved with `yargs.argv`.
|
|
|
|
.showHelpOnFail(enable, [message])
|
|
----------------------------------
|
|
|
|
By default, yargs outputs a usage string if any error is detected. Use the
|
|
`.showHelpOnFail()` method to customize this behavior. If `enable` is `false`,
|
|
the usage string is not output. If the `message` parameter is present, this
|
|
message is output after the error message.
|
|
|
|
line_count.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.usage('Count the lines in a file.\nUsage: $0 -f <file>')
|
|
.demand('f')
|
|
.alias('f', 'file')
|
|
.describe('f', 'Load a file')
|
|
.string('f')
|
|
.showHelpOnFail(false, 'Specify --help for available options')
|
|
.help('help')
|
|
.argv;
|
|
|
|
// etc.
|
|
````
|
|
|
|
***
|
|
|
|
```
|
|
$ node line_count.js
|
|
Missing argument value: f
|
|
|
|
Specify --help for available options
|
|
```
|
|
|
|
.strict()
|
|
---------
|
|
|
|
Any command-line argument given that is not demanded, or does not have a
|
|
corresponding description, will be reported as an error.
|
|
|
|
<a name="string"></a>.string(key)
|
|
------------
|
|
|
|
Tell the parser logic not to interpret `key` as a number or boolean.
|
|
This can be useful if you need to preserve leading zeros in an input.
|
|
|
|
If `key` is an array, interpret all the elements as strings.
|
|
|
|
`.string('_')` will result in non-hyphenated arguments being interpreted as strings,
|
|
regardless of whether they resemble numbers.
|
|
|
|
.updateLocale(obj)
|
|
------------------
|
|
.updateStrings(obj)
|
|
------------------
|
|
|
|
Override the default strings used by yargs with the key/value
|
|
pairs provided in `obj`:
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.command('run', 'the run command')
|
|
.help('help')
|
|
.updateStrings({
|
|
'Commands:': 'My Commands -->\n'
|
|
})
|
|
.wrap(null)
|
|
.argv
|
|
```
|
|
|
|
***
|
|
|
|
```shell
|
|
My Commands -->
|
|
|
|
run the run command
|
|
|
|
Options:
|
|
--help Show help [boolean]
|
|
```
|
|
|
|
If you explicitly specify a `locale()`, you should do so *before* calling
|
|
`updateStrings()`.
|
|
|
|
.usage(message, [opts])
|
|
---------------------
|
|
|
|
Set a usage message to show which commands to use. Inside `message`, the string
|
|
`$0` will get interpolated to the current script name or node command for the
|
|
present script similar to how `$0` works in bash or perl.
|
|
|
|
`opts` is optional and acts like calling `.options(opts)`.
|
|
|
|
.version(version, [option], [description])
|
|
----------------------------------------
|
|
|
|
Add an option (e.g. `--version`) that displays the version number (given by the
|
|
`version` parameter) and exits the process. If present, the `description`
|
|
parameter customizes the description of the version option in the usage string.
|
|
|
|
You can provide a `function` for version, rather than a string.
|
|
This is useful if you want to use the version from your package.json:
|
|
|
|
```js
|
|
var argv = require('yargs')
|
|
.version(function() {
|
|
return require('../package').version;
|
|
})
|
|
.argv;
|
|
```
|
|
|
|
.wrap(columns)
|
|
--------------
|
|
|
|
Format usage output to wrap at `columns` many columns.
|
|
|
|
By default wrap will be set to `Math.min(80, windowWidth)`. Use `.wrap(null)` to
|
|
specify no column limit (no right-align). Use `.wrap(yargs.terminalWidth())` to
|
|
maximize the width of yargs' usage instructions.
|
|
|
|
parsing tricks
|
|
==============
|
|
|
|
stop parsing
|
|
------------
|
|
|
|
Use `--` to stop parsing flags and stuff the remainder into `argv._`.
|
|
|
|
$ node examples/reflect.js -a 1 -b 2 -- -c 3 -d 4
|
|
{ _: [ '-c', '3', '-d', '4' ],
|
|
a: 1,
|
|
b: 2,
|
|
'$0': 'examples/reflect.js' }
|
|
|
|
negate fields
|
|
-------------
|
|
|
|
If you want to explicitly set a field to false instead of just leaving it
|
|
undefined or to override a default you can do `--no-key`.
|
|
|
|
$ node examples/reflect.js -a --no-b
|
|
{ _: [], a: true, b: false, '$0': 'examples/reflect.js' }
|
|
|
|
numbers
|
|
-------
|
|
|
|
Every argument that looks like a number (`!isNaN(Number(arg))`) is converted to
|
|
one. This way you can just `net.createConnection(argv.port)` and you can add
|
|
numbers out of `argv` with `+` without having that mean concatenation,
|
|
which is super frustrating.
|
|
|
|
duplicates
|
|
----------
|
|
|
|
If you specify a flag multiple times it will get turned into an array containing
|
|
all the values in order.
|
|
|
|
$ node examples/reflect.js -x 5 -x 8 -x 0
|
|
{ _: [], x: [ 5, 8, 0 ], '$0': 'examples/reflect.js' }
|
|
|
|
dot notation
|
|
------------
|
|
|
|
When you use dots (`.`s) in argument names, an implicit object path is assumed.
|
|
This lets you organize arguments into nested objects.
|
|
|
|
$ node examples/reflect.js --foo.bar.baz=33 --foo.quux=5
|
|
{ _: [],
|
|
foo: { bar: { baz: 33 }, quux: 5 },
|
|
'$0': 'examples/reflect.js' }
|
|
|
|
short numbers
|
|
-------------
|
|
|
|
Short numeric `-n5` style arguments work too:
|
|
|
|
$ node examples/reflect.js -n123 -m456
|
|
{ _: [], n: 123, m: 456, '$0': 'examples/reflect.js' }
|
|
|
|
installation
|
|
============
|
|
|
|
With [npm](https://github.com/npm/npm), just do:
|
|
|
|
npm install yargs
|
|
|
|
or clone this project on github:
|
|
|
|
git clone http://github.com/bcoe/yargs.git
|
|
|
|
To run the tests with npm, just do:
|
|
|
|
npm test
|
|
|
|
inspired by
|
|
===========
|
|
|
|
This module is loosely inspired by Perl's
|
|
[Getopt::Casual](http://search.cpan.org/~photo/Getopt-Casual-0.13.1/Casual.pm).
|
|
|
|
|
|
|
|
[travis-url]: https://travis-ci.org/bcoe/yargs
|
|
[travis-image]: https://img.shields.io/travis/bcoe/yargs.svg
|
|
[gemnasium-url]: https://gemnasium.com/bcoe/yargs
|
|
[gemnasium-image]: https://img.shields.io/gemnasium/bcoe/yargs.svg
|
|
[coveralls-url]: https://coveralls.io/github/bcoe/yargs
|
|
[coveralls-image]: https://img.shields.io/coveralls/bcoe/yargs.svg
|
|
[npm-url]: https://www.npmjs.com/package/yargs
|
|
[npm-image]: https://img.shields.io/npm/v/yargs.svg
|
|
[windows-url]: https://ci.appveyor.com/project/bcoe/yargs
|
|
[windows-image]: https://img.shields.io/appveyor/ci/bcoe/yargs/master.svg?label=Windows%20Tests
|