I don't want to maintain this module anymore since I just use minimist, the argument parsing engine, directly instead nowadays.
See yargs for the modern, pirate-themed successor to optimist.
You should also consider nomnom.
Optimist is a node.js library for option parsing for people who hate option parsing. More specifically, this module is for people who like all the --bells and -whistlz of program usage but think optstrings are a waste of time.
With optimist, option parsing doesn't have to suck (as much).
xup.js:
#!/usr/bin/env node
var argv = require('optimist').argv;
if (argv.rif - 5 * argv.xup > 7.138) {
console.log('Buy more riffiwobbles');
}
else {
console.log('Sell the xupptumblers');
}
$ ./xup.js --rif=55 --xup=9.52
Buy more riffiwobbles
$ ./xup.js --rif 12 --xup 8.1
Sell the xupptumblers
short.js:
#!/usr/bin/env node
var argv = require('optimist').argv;
console.log('(%d,%d)', argv.x, argv.y);
$ ./short.js -x 10 -y 21
(10,21)
bool.js:
#!/usr/bin/env node
var util = require('util');
var argv = require('optimist').argv;
if (argv.s) {
util.print(argv.fr ? 'Le chat dit: ' : 'The cat says: ');
}
console.log(
(argv.fr ? 'miaou' : 'meow') + (argv.p ? '.' : '')
);
$ ./bool.js -s
The cat says: meow
$ ./bool.js -sp
The cat says: meow.
$ ./bool.js -sp --fr
Le chat dit: miaou.
argv._
!nonopt.js:
#!/usr/bin/env node
var argv = require('optimist').argv;
console.log('(%d,%d)', argv.x, argv.y);
console.log(argv._);
$ ./nonopt.js -x 6.82 -y 3.35 moo
(6.82,3.35)
[ 'moo' ]
$ ./nonopt.js foo -x 0.54 bar -y 1.12 baz
(0.54,1.12)
[ 'foo', 'bar', 'baz' ]
divide.js:
#!/usr/bin/env node
var argv = require('optimist')
.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
default_singles.js:
#!/usr/bin/env node
var argv = require('optimist')
.default('x', 10)
.default('y', 10)
.argv
;
console.log(argv.x + argv.y);
$ ./default_singles.js -x 5
15
default_hash.js:
#!/usr/bin/env node
var argv = require('optimist')
.default({ x : 10, y : 10 })
.argv
;
console.log(argv.x + argv.y);
$ ./default_hash.js -y 7
17
boolean_single.js
#!/usr/bin/env node
var argv = require('optimist')
.boolean('v')
.argv
;
console.dir(argv);
$ ./boolean_single.js -v foo bar baz
true
[ 'bar', 'baz', 'foo' ]
boolean_double.js
#!/usr/bin/env node
var argv = require('optimist')
.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' ]
You can describe parameters for help messages and set aliases. Optimist figures out how to format a handy help string automatically.
line_count.js
#!/usr/bin/env node
var argv = require('optimist')
.usage('Count the lines in a file.\nUsage: $0')
.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
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
By itself,
require('optimist').argv
will use process.argv
array to construct the argv
object.
You can pass in the process.argv
yourself:
require('optimist')([ '-x', '1', '-y', '2' ]).argv
or use .parse() to do the same thing:
require('optimist').parse([ '-x', '1', '-y', '2' ])
The rest of these methods below come in just before the terminating .argv
.
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.
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.
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.
Describe a key
for the generated usage information.
Optionally .describe()
can take an object that maps keys to descriptions.
Instead of chaining together .alias().demand().default()
, you can specify
keys in opt
for each of the chainable methods.
For example:
var argv = require('optimist')
.options('f', {
alias : 'file',
default : '/etc/passwd',
})
.argv
;
is the same as
var argv = require('optimist')
.alias('f', 'file')
.default('f', '/etc/passwd')
.argv
;
Optionally .options()
can take an object that maps keys to opt
parameters.
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.
Check that certain conditions are met in the provided arguments.
If fn
throws or returns false
, show the thrown error, usage information, and
exit.
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.
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.
Format usage output to wrap at columns
many columns.
Return the generated usage string.
Print the usage data using fn
for printing.
Parse args
instead of process.argv
. Returns the argv
object.
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.
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 }
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 }
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.
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 ] }
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 numeric head -n5
style argument work too:
$ node reflect.js -n123 -m456
{ '3': true,
'6': true,
_: [],
'$0': 'node ./reflect.js',
n: 123,
m: 456 }
With npm, just do: npm install optimist
or clone this project on github:
git clone http://github.com/substack/node-optimist.git
To run the tests with expresso, just do:
expresso
This module is loosely inspired by Perl's Getopt::Casual.
# DEPRECATION NOTICE I don't want to maintain this module anymore since I just use [minimist](https://npmjs.org/package/minimist), the argument parsing engine, directly instead nowadays. See [yargs](https://github.com/chevex/yargs) for the modern, pirate-themed successor to optimist. [![yarrrrrrrgs!](http://i.imgur.com/4WFGVJ9.png)](https://github.com/chevex/yargs) You should also consider [nomnom](https://github.com/harthur/nomnom). optimist ======== Optimist is a node.js library for option parsing for people who hate option parsing. More specifically, this module is for people who like all the --bells and -whistlz of program usage but think optstrings are a waste of time. With optimist, option parsing doesn't have to suck (as much). [![build status](https://secure.travis-ci.org/substack/node-optimist.png)](http://travis-ci.org/substack/node-optimist) examples ======== With Optimist, the options are just a hash! No optstrings attached. ------------------------------------------------------------------- xup.js: ````javascript #!/usr/bin/env node var argv = require('optimist').argv; if (argv.rif - 5 * argv.xup > 7.138) { console.log('Buy more riffiwobbles'); } else { console.log('Sell the xupptumblers'); } ```` *** $ ./xup.js --rif=55 --xup=9.52 Buy more riffiwobbles $ ./xup.js --rif 12 --xup 8.1 Sell the xupptumblers ![This one's optimistic.](http://substack.net/images/optimistic.png) But wait! There's more! You can do short options: ------------------------------------------------- short.js: ````javascript #!/usr/bin/env node var argv = require('optimist').argv; console.log('(%d,%d)', argv.x, argv.y); ```` *** $ ./short.js -x 10 -y 21 (10,21) And booleans, both long and short (and grouped): ---------------------------------- bool.js: ````javascript #!/usr/bin/env node var util = require('util'); var argv = require('optimist').argv; if (argv.s) { util.print(argv.fr ? 'Le chat dit: ' : 'The cat says: '); } console.log( (argv.fr ? 'miaou' : 'meow') + (argv.p ? '.' : '') ); ```` *** $ ./bool.js -s The cat says: meow $ ./bool.js -sp The cat says: meow. $ ./bool.js -sp --fr Le chat dit: miaou. And non-hypenated options too! Just use `argv._`! ------------------------------------------------- nonopt.js: ````javascript #!/usr/bin/env node var argv = require('optimist').argv; console.log('(%d,%d)', argv.x, argv.y); console.log(argv._); ```` *** $ ./nonopt.js -x 6.82 -y 3.35 moo (6.82,3.35) [ 'moo' ] $ ./nonopt.js foo -x 0.54 bar -y 1.12 baz (0.54,1.12) [ 'foo', 'bar', 'baz' ] Plus, Optimist comes with .usage() and .demand()! ------------------------------------------------- divide.js: ````javascript #!/usr/bin/env node var argv = require('optimist') .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 EVEN MORE HOLY COW ------------------ default_singles.js: ````javascript #!/usr/bin/env node var argv = require('optimist') .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('optimist') .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('optimist') .boolean('v') .argv ; console.dir(argv); ```` *** $ ./boolean_single.js -v foo bar baz true [ 'bar', 'baz', 'foo' ] boolean_double.js ````javascript #!/usr/bin/env node var argv = require('optimist') .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' ] Optimist is here to help... --------------------------- You can describe parameters for help messages and set aliases. Optimist figures out how to format a handy help string automatically. line_count.js ````javascript #!/usr/bin/env node var argv = require('optimist') .usage('Count the lines in a file.\nUsage: $0') .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 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('optimist').argv ````` will use `process.argv` array to construct the `argv` object. You can pass in the `process.argv` yourself: ````javascript require('optimist')([ '-x', '1', '-y', '2' ]).argv ```` or use .parse() to do the same thing: ````javascript require('optimist').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. .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) ------------ 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. .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('optimist') .options('f', { alias : 'file', default : '/etc/passwd', }) .argv ; ```` is the same as ````javascript var argv = require('optimist') .alias('f', 'file') .default('f', '/etc/passwd') .argv ; ```` Optionally `.options()` can take an object that maps keys to `opt` parameters. .usage(message) --------------- 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. .check(fn) ---------- Check that certain conditions are met in the provided arguments. 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. .wrap(columns) -------------- Format usage output to wrap at `columns` many columns. .help() ------- Return the generated usage string. .showHelp(fn=console.error) --------------------------- Print the usage data using `fn` for printing. .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 optimist or clone this project on github: git clone http://github.com/substack/node-optimist.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).