mirror of
https://github.com/thangisme/notes.git
synced 2024-12-22 21:06:26 -05:00
682 lines
16 KiB
Markdown
682 lines
16 KiB
Markdown
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.
|
|
|
|
[](https://travis-ci.org/chevex/yargs)
|
|
[](https://gemnasium.com/chevex/yargs)
|
|
[](http://badge.fury.io/js/yargs)
|
|
|
|
> ~~NOTE: Yargs is a fork of [optimist](https://github.com/substack/node-optimist) by [substack (James Halliday)](https://github.com/substack). It is obvious that substack is stretched pretty thin maintaining over 300 modules on npm at the time of this writing. So rather than complain in the project issue tracker I thought I'd just pick up the torch and maintain a proper fork. Currently the project is totally backward compatible with optimist but this may change in the future (if it does I will update this notice to inform you of this). For now though, enjoy optimist with about 5 months worth of fixes and updates rolled in, most of them pulled from optimist's own [stale pull requests](https://github.com/substack/node-optimist/pulls).~~
|
|
|
|
> UPDATE: Yargs is now the official successor to optimist. Please feel free to submit issues and pull requests. While I personally don't have the time to pore over all the issues and fix all of them on a regular basis, I'm more than happy to look over pull requests, test them, and merge them in. If you'd like to contribute and don't know where to start, have a look at [the issue list](https://github.com/chevex/yargs/issues) :)
|
|
|
|
examples
|
|
========
|
|
|
|
With yargs, the options be just a hash!
|
|
-------------------------------------------------------------------
|
|
|
|
xup.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs').argv;
|
|
|
|
if (argv.rif - 5 * argv.xup > 7.138) {
|
|
console.log('Plunder more riffiwobbles!');
|
|
}
|
|
else {
|
|
console.log('Drop the xupptumblers!');
|
|
}
|
|
````
|
|
|
|
***
|
|
|
|
$ ./xup.js --rif=55 --xup=9.52
|
|
Plunder more riffiwobbles!
|
|
|
|
$ ./xup.js --rif 12 --xup 8.1
|
|
Drop 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 util = require('util');
|
|
var argv = require('yargs').argv;
|
|
|
|
if (argv.s) {
|
|
util.print(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-mportant 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.
|
|
-------------------------------------------------
|
|
|
|
divide.js:
|
|
|
|
````javascript
|
|
#!/usr/bin/env node
|
|
var argv = require('yargs')
|
|
.usage('Usage: $0 -x [num] -y [num]')
|
|
.demand(['x','y'])
|
|
.argv;
|
|
|
|
console.log(argv.x / argv.y);
|
|
````
|
|
|
|
***
|
|
|
|
$ ./divide.js -x 55 -y 11
|
|
5
|
|
|
|
$ node ./divide.js -x 4.91 -z 2.51
|
|
Usage: node ./divide.js -x [num] -y [num]
|
|
|
|
Options:
|
|
-x [required]
|
|
-y [required]
|
|
|
|
Missing required arguments: y
|
|
|
|
After yer demands have been met, demand more! Ask for non-hypenated 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 arguments, expected 2, but only found 1
|
|
$ ./demand_count.js a b
|
|
{ _: [ 'a', 'b' ], '$0': 'node ./demand_count.js' }
|
|
$ ./demand_count.js a b c
|
|
{ _: [ 'a', 'b', 'c' ], '$0': 'node ./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('Count the lines in a file.\nUsage: $0')
|
|
.example('$0 -f', 'count the lines in the given file')
|
|
.demand('f')
|
|
.alias('f', 'file')
|
|
.describe('f', 'Load a file')
|
|
.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 the lines in a file.
|
|
Usage: node ./line_count.js
|
|
|
|
Examples:
|
|
node ./line_count.js -f count the lines in the given file
|
|
|
|
Options:
|
|
-f, --file Load a file [required]
|
|
|
|
Missing required arguments: f
|
|
|
|
$ node line_count.js --file line_count.js
|
|
20
|
|
|
|
$ node line_count.js -f line_count.js
|
|
20
|
|
|
|
methods
|
|
=======
|
|
|
|
By itself,
|
|
|
|
````javascript
|
|
require('yargs').argv
|
|
`````
|
|
|
|
will use `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`.
|
|
|
|
.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.
|
|
|
|
.default(key, value)
|
|
--------------------
|
|
|
|
Set `argv[key]` to `value` if no option was specified on `process.argv`.
|
|
|
|
Optionally `.default()` can take an object that maps keys to default values.
|
|
|
|
.demand(key, [msg | boolean])
|
|
-----------------------------
|
|
.require(key, [msg | boolean])
|
|
------------------------------
|
|
.required(key, [msg | boolean])
|
|
-------------------------------
|
|
|
|
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._`.
|
|
|
|
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.
|
|
|
|
.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 behaviour is to set the value of any key not followed by an
|
|
option value to `true`.
|
|
|
|
.describe(key, desc)
|
|
--------------------
|
|
|
|
Describe a `key` for the generated usage information.
|
|
|
|
Optionally `.describe()` can take an object that maps keys to descriptions.
|
|
|
|
.options(key, opt)
|
|
------------------
|
|
|
|
Instead of chaining together `.alias().demand().default()`, you can specify
|
|
keys in `opt` for each of the chainable methods.
|
|
|
|
For example:
|
|
|
|
````javascript
|
|
var argv = require('yargs')
|
|
.options('f', {
|
|
alias : 'file',
|
|
default : '/etc/passwd',
|
|
})
|
|
.argv
|
|
;
|
|
````
|
|
|
|
is the same as
|
|
|
|
````javascript
|
|
var argv = require('yargs')
|
|
.alias('f', 'file')
|
|
.default('f', '/etc/passwd')
|
|
.argv
|
|
;
|
|
````
|
|
|
|
Optionally `.options()` can take an object that maps keys to `opt` parameters.
|
|
|
|
.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)`.
|
|
|
|
.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.
|
|
|
|
.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 `false`, show the thrown error, usage information, and
|
|
exit.
|
|
|
|
.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`.
|
|
|
|
If `key` never shows up as a flag in `process.arguments`, `argv[key]` will be
|
|
`false`.
|
|
|
|
If `key` is an Array, interpret all the elements as booleans.
|
|
|
|
.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.
|
|
|
|
.config(key)
|
|
------------
|
|
|
|
Tells the parser to interpret `key` as a path to a JSON config file. The file
|
|
is loaded and parsed, and its properties are set as arguments.
|
|
|
|
.wrap(columns)
|
|
--------------
|
|
|
|
Format usage output to wrap at `columns` many columns.
|
|
|
|
.strict()
|
|
---------
|
|
|
|
Any command-line argument given that is not demanded, or does not have a
|
|
corresponding description, will be reported as an error.
|
|
|
|
.help([option, [description]])
|
|
------------------------------
|
|
|
|
Add an option (e.g., `--help`) that displays the usage string and exits the
|
|
process. If present, the `description` parameter customises the description of
|
|
the help option in the usage string.
|
|
|
|
If invoked without parameters, `.help` returns the generated usage string.
|
|
|
|
Example:
|
|
|
|
```
|
|
var yargs = require("yargs")
|
|
.usage("$0 -operand1 number -operand2 number -operation [add|subtract]");
|
|
console.log(yargs.help());
|
|
```
|
|
|
|
Later on, ```argv``` can be retrived with ```yargs.argv```
|
|
|
|
.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 customises the description of the version option in the usage string.
|
|
|
|
.showHelpOnFail(enable, [message])
|
|
----------------------------------
|
|
|
|
By default, yargs outputs a usage string if any error is detected. Use the
|
|
`.showHelpOnFail` method to customize this behaviour. 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')
|
|
.demand('f')
|
|
.alias('f', 'file')
|
|
.describe('f', 'Load a file')
|
|
.showHelpOnFail(false, "Specify --help for available options")
|
|
.argv;
|
|
|
|
// etc.
|
|
````
|
|
|
|
***
|
|
|
|
$ node line_count.js --file
|
|
Missing argument value: f
|
|
|
|
Specify --help for available options
|
|
|
|
.showHelp(fn=console.error)
|
|
---------------------------
|
|
|
|
Print the usage data using `fn` for printing.
|
|
|
|
Example:
|
|
|
|
```
|
|
var yargs = require("yargs")
|
|
.usage("$0 -operand1 number -operand2 number -operation [add|subtract]");
|
|
yargs.showHelp();
|
|
```
|
|
|
|
Later on, ```argv``` can be retrived with ```yargs.argv```
|
|
|
|
.parse(args)
|
|
------------
|
|
|
|
Parse `args` instead of `process.argv`. Returns the `argv` object.
|
|
|
|
.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.
|
|
|
|
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' ],
|
|
'$0': 'node ./examples/reflect.js',
|
|
a: 1,
|
|
b: 2 }
|
|
|
|
negate fields
|
|
-------------
|
|
|
|
If you want to explicity 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
|
|
{ _: [],
|
|
'$0': 'node ./examples/reflect.js',
|
|
a: true,
|
|
b: false }
|
|
|
|
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
|
|
{ _: [],
|
|
'$0': 'node ./examples/reflect.js',
|
|
x: [ 5, 8, 0 ] }
|
|
|
|
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
|
|
{ _: [],
|
|
'$0': 'node ./examples/reflect.js',
|
|
foo: { bar: { baz: 33 }, quux: 5 } }
|
|
|
|
short numbers
|
|
-------------
|
|
|
|
Short numeric `head -n5` style argument work too:
|
|
|
|
$ node reflect.js -n123 -m456
|
|
{ '3': true,
|
|
'6': true,
|
|
_: [],
|
|
'$0': 'node ./reflect.js',
|
|
n: 123,
|
|
m: 456 }
|
|
|
|
installation
|
|
============
|
|
|
|
With [npm](http://github.com/isaacs/npm), just do:
|
|
|
|
npm install yargs
|
|
|
|
or clone this project on github:
|
|
|
|
git clone http://github.com/chevex/yargs.git
|
|
|
|
To run the tests with [expresso](http://github.com/visionmedia/expresso),
|
|
just do:
|
|
|
|
expresso
|
|
|
|
inspired By
|
|
===========
|
|
|
|
This module is loosely inspired by Perl's
|
|
[Getopt::Casual](http://search.cpan.org/~photo/Getopt-Casual-0.13.1/Casual.pm).
|