docopt
v0.6.2
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a command line option parser that will make you smile
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docopt
– a command line option parser that will make you smile
docopt is a language for description of command-line interfaces. This is
docopt
implementation in CoffeeScript, that could be used for server-side CoffeeScript and JavaScript programs.
Isn't it awesome how modern command-line arguments parsers generate help message based on your code?!
Hell no! You know what's awesome? When the option parser is generated based on the help message that you write yourself! This way you don't need to write this stupid repeatable parser-code, and instead can write a beautiful help message (the way you want it!), which adds readability to your code.
Now you can write an awesome, readable, clean, DRY code like this:
doc = """
Usage:
quick_example.coffee tcp <host> <port> [--timeout=<seconds>]
quick_example.coffee serial <port> [--baud=9600] [--timeout=<seconds>]
quick_example.coffee -h | --help | --version
"""
{docopt} = require '../docopt'
console.log docopt(doc, version: '0.1.1rc')
Hell yeah! The option parser is generated based on doc
string above, that you
pass to the docopt
function.
API {docopt} = require 'docopt'
options = docopt(doc, {argv: process.argv[2..], help: true, version: null, options_first: false, exit: true})
docopt
takes 1 required argument, and 3 optional keyword arguments:
doc
(required) should be a string with the help message, written according to rules of the docopt language. Here's a quick example:Usage: your_program [options] -h --help Show this. -v --verbose Print more text. --quiet Print less text. -o FILE Specify output file [default: ./test.txt].
argv
is an optional argument vector. It defaults to the arguments passed to your program (process.argv[2..]
). You can also supply it with an array of strings, as withprocess.argv
. For example:['--verbose', '-o', 'hai.txt']
.help
(default:true
) specifies whether the parser should automatically print the help message (supplied asdoc
) in case-h
or--help
options are encountered. After showing the usage-message, the program will terminate. If you want to handle-h
or--help
options manually (the same as other options), sethelp=false
.version
(default:null
) is an optional argument that specifies the version of your program. If supplied, then, if the parser encounters--version
option, it will print the supplied version and terminate.version
could be any printable object, but most likely a string, e.g.'2.1.0rc1'
.options_first
, by defaultfalse
. If set totrue
will disallow mixing options and positional argument. I.e. after first positional argument, all arguments will be interpreted as positional even if the look like options. This can be used for strict compatibility with POSIX, or if you want to dispatch your arguments to other programs.exit
, by defaulttrue
. If set tofalse
will cause docopt to throw exceptions instead of printing the error to console and terminating the application. This flag is mainly for testing purposes.
Note: Although docopt
automatically handles -h
, --help
and --version
options,
you still need to mention them in the options description (doc
) for your users to
know about them.
The return value is an Object
with properties (giving long options precedence),
like this:
{'--timeout': '10',
'--baud': '4800',
'--version': false,
'--help': false,
'-h': false,
serial: true,
tcp: false,
'<host>': false,
'<port>': '/dev/ttyr01'}