Capitano
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Capitano allows you to craft powerful command line applications, your way.
capitano = require('capitano')
capitano.permission 'jviotti', (done) ->
return done() if process.env.USER is 'jviotti'
done(new Error('You are not jviotti!'))
capitano.command
signature: 'utils print <title> [words...]'
options: [
signature: 'date'
boolean: true
alias: [ 'd' ]
]
permission: 'jviotti'
action: (params, options) ->
log = ''
if options.date
log += "#{new Date()} "
log += "#{params.title}: #{params.words}"
console.log(log)
capitano.run process.argv, (error) ->
throw error if error?
$ myCoolApp utils print Error Something very bad happened
Error: Something very bad happened
$ myCoolApp utils print Error Something very bad happened -d
Thu Dec 18 2014 14:49:27 GMT-0400 (BOT) Error: Something very bad happened
We wrote Capitano as we couldn't find any NodeJS command line parser that met our needs. Alternatives such as commander.js, albeit being very good, didn't have good support for features such as infinitely nested git-like subcommands, per-command options and complete customisation. Capitano is our attempt at creating a non opitionated command line parser that can do everything you can imagine.
Features
- Infinitely nested git-like subcommands.
- Global and per-command options.
- Variadic arguments.
- Option aliases.
- Stdin support out of the box.
- Separate between parsing and executing command line arguments.
- No built-in generated help page, you roll your own.
- No built-in commands, you have a high degree of control over your app.
- Permission support.
Installation
Install capitano
by running:
$ npm install --save capitano
API
capitano.command(options)
Register a command. Capitano understands the following options, but you can pass custom options to do nifty things (see the examples section):
signature (string)
The command signature. If it's *
, it will match anything that is not matched by other commands.
You can represent a command that allows input from stdin with the following syntax:
- Required:
<|foo>
. - Optional:
[|foo]
.
Notice that you can only have one stdin command per signature, and it has to be the last parameter of the signature. See the examples section for a stdin example.
action (function)
Function to call when the signature is matched. This function gets passed a parameter object, an options object and a callback
to be called when the action is finished.
If the callback
argument is not declared in the action function, it'll be called implicitly, however in order to ensure Capitano works as expected, call the callback
function if your action is async.
options ([object])
Array of objects describing the options specific to this command. See the options section for more information.
permission (string)
Require a certain previously registered permission by name. If the permission requirements are not met, the command action will not be called and capitano.execute()
, or capitano.run()
will get the error you passed in from the permission function in their callbacks.
Notice that Capitano doesn't currently supports passing an array of permissions. If you have that specific use case, you'll have to create a new permission that combines the other ones.
root (boolean)
If you specify this option to true, then the command will only be runnable by a user with admin privileges, or prefixed by sudo
.
capitano.globalOption(options)
Register a global option, which will be accessible from every command (and from outside too!) so be careful about naming collisions!
It accepts an object containing the following options:
signature (string)
The option signature excluding any parameter (foo
instead of foo <bar>
).
boolean (boolean)
Whether the option is boolean (doesn't accepts any parameters). It defaults to false
. If parameter
is defined, then boolean
should be false
.
parameter (string)
The name of the parameter, excluding required/optional tags (bar
instead of <bar>
). Notice that if you set boolean: true
, then you have to omit this option.
alias (string|[string])
Define an alias, or a set of alias for an option. Aliases can contain single letter abbreviations (f
, l
) or full option names (baz
, foo
).
capitano.permission(name, function)
It registers a permission function under a certain name. The permission function is passed a done()
function that accepts an error instance in case the user doesn't fits the permission requirements. Pass nothing if the permission requirement was matched.
Note: You must call the done()
function, even if your permission function is synchronous, in order for Capitano to continue.
capitano.run(argv, callback)
Run and execute the application given a set of arguments (usually process.argv
):
capitano.run(process.argv)
This is also the command you need to use if you need to call a command from another command. For example:
capitano.run('my other command --foo bar', callback)
Note: capitano.run
is a shorcut function for capitano.execute(capitano.parse(argv), callback)
. You will usually use this function, however you can use parse()
and execute()
in particular situations when you need to differenciate between parsing and executing the commands.
capitano.parse(argv)
Parse, but not execute the command line arguments (usually process.argv
).
It returns a cli
object containing three fields:
command (string)
A string representing the issued command, omitting any option.
options (object)
An object containing the raw representation of the given options.
globals (object)
An object containing the matches and parsed global options.
capitano.execute(cli, callback)
It accepts a cli
object (returned by capitano.parse()) and
executes the corresponding command, with it's corresponding options.
You're expected to provide your own error handling mechanism here, or in the capitano.run
if executing from there.
capitano.state
An object containing the current registered commands an options. As with Capitano you're expected to implement every command (including help
, etc) this object comes handy to accomplish a wide range of tasks.
It includes the following fields:
commands (array)
An array containing every registered command so far (with capitano.command()
)
See the Command class for more information.
globalOptions (array)
An array containing every registered global option so far (with capitano.globalOption()
).
See the Option class for more information.
findCommandBySignature(signature)
A self explanatory function that returns a command that matches a specific signature.
getMatchCommand(signature, callback)
Get command that matches a signature, without taking parameters into account.
This means that a command app create <id>
will be matched by a signature app create
.
capitano.defaults
An object containing some settings used by Capitano.
It includes the following fields:
signatures.wildcard (string)
The wildcard symbol. Defaults to *
.actions.commandNotFound(signature)
The function called when a command was not found. By default, it prints a boring Command not found: <signature>
and exits with an error code 1.
Pro tip: If you want to modify these settings, do it as early as possible (before registering any commands/global options) as some settings are used when performing the mentioned tasks.
capitano.utils
A collection of handy utilities for working with Capitano.
capitano.utils.getStdin(callback)
Read from stdin. This function is used when you specify a stdin parameter, such as <|foo>
.
You'll most often use the stdin parameter syntax, but this function is publicly available in case you need more control.
Example:
capitano = require('capitano')
capitano.utils.getStdin (data) ->
console.log("We got #{data} from stdin")
Classes
Command
The Capitano Command class contains the following public fields:
Command#signature (Signature)
See the Signature class.
Command#options ([Option])
An array of Option classes.
Command#isWildcard()
A predicate method that returns true
if a command represents a wildcard.
Signature
The Capitano Signature class contains the following public fields:
Signature#hasParameters()
A predicate method that returns true
if the signature has at least one parameter.
Signature#hasVariadicParameters()
A predicate method that returns true
if the signature has at least one variadic parameter.
Signature#isWildcard()
A predicate method that returns true
if the signature represents a wildcard.
Signature#allowsStdin()
A predicate method that returns true
if the signature has at least one stdin parameter.
Option
The Capitano Option class contains the following public fields:
Option#signature
See Signature class.
Option#alias (string|[string])
A string or array of string alias.
Option#boolean (boolean)
Whether the option is boolean or not.
Option#parameter (string)
An option parameter (optional).
Option#required (boolean|string)
Defines whether an option is required. If the field is true
, a generic error is thrown, otherwise you can set a custom error message by setting to a string
.
Examples
Capitano is very flexible, allowing you to implement all sort of crazy stuff. Here I present some common patterns that I've been doing on Capitano. If you have an interesting idea that you think it's worth to share, please submit a PR!
Stdin input
capitano = require('capitano')
capitano.command
signature: 'foo <|bar>'
description: 'a command that accepts stdin input'
action: (params, options, done) ->
console.log("The input is: #{params.bar}")
done()
capitano.run process.argv, (error) ->
throw error if error?
$ echo "Hello World" | stdinApp foo
The input is: Hello World
$ stdinApp foo "Hello World"
The input is: Hello World
Generated help
Notice this is a very rudimentary help page and lacks features such as printing global options, command specific options, handling correct aligment, etc, but you can at least get an idea on how to implement this for yourself.
capitano = require('capitano')
capitano.command
signature: 'version'
description: 'output version information'
action: ...
capitano.command
signature: 'help'
description: 'output general help page'
action: ->
console.log("Usage: #{myAppName} [COMMANDS] [OPTIONS]")
console.log('\nCommands:\n')
for command in capitano.state.commands
continue if command.isWildcard()
console.log("\t#{command.signature}\t\t\t"#{command.description})
capitano.run process.argv, (error) ->
throw error if error?
$ app help
Usage: MyCoolApp [COMMANDS] [OPTIONS]
Commands:
version output version information
help output general help page
Command specific help pages
capitano = require('capitano')
capitano.command
signature: 'version'
description: 'output version information'
help: '''
Software versioning is the process of assigning either unique version names or unique version numbers to unique states of computer software. Within a given version number category (major, minor), these numbers are generally assigned in increasing order and correspond to new developments in the software. At a fine-grained level, revision control is often used for keeping track of incrementally different versions of electronic information, whether or not this information is computer software.
'''
action: ...
capitano.command
signature: 'help [command...]'
description: 'output general help page'
action: (params, options, done) ->
return outputGeneralHelp() if not params?
capitano.state.getMatchCommand params.command, (error, command) ->
return done(error) if error?
if not command? or command.isWildcard()
return capitano.defaults.actions.commandNotFound(params.command)
console.log(command.help)
done()
capitano.run process.argv, (error) ->
throw error if error?
$ app help version
Software versioning is the process of assigning either unique version names or unique version numbers to unique states of computer software. Within a given version number category (major, minor), these numbers are generally assigned in increasing order and correspond to new developments in the software. At a fine-grained level, revision control is often used for keeping track of incrementally different versions of electronic information, whether or not this information is computer software.
Tests
Run the test suite by doing:
$ gulp test
ChangeLog
1.7.3
- Don't evaluate numbers in scientific notation automatically.
1.7.2
- Replace
minimist
with yargs-parser
.
1.7.1
- Fix required options errors being thrown synchronously.
1.7.0
- Add
option#toString()
method as an utility build help pages.
1.6.2
- Add
EACCES
code to the error thrown on "root" commands.
1.6.1
- Fix issue with command option values that started with numbers.
1.6.0
- Implement root property support.
1.5.0
- Expose internal utils object as
capitano.utils
.
1.4.0
Notice capitano.state.getMatchCommand()
is now async.
1.3.1
- Catch action errors and send them to the callback automatically. See #17.
1.3.0
- Implement permission support. Discussed in #15.
1.2.0
- Implement action callback support. Discussed in #11.
1.1.1
- Fix issue with parsing words that start with a number.
1.1.0
- Implement support for required options.
1.0.4
- Fix issue when instantiating Parameter instances with a number directly.
1.0.3
- Fix issue with quotation of multi word parameters. Thanks @Page-!
1.0.2
1.0.1
- Fix issues with path and quoted multi string parameters.
Contribute
Before submitting a PR, please make sure that you include tests, and that coffeelint runs without any warning:
$ gulp lint
Support
If you're having any problem, please raise an issue on GitHub.
TODO
- Options default values.
- Allow comma-separated parameter values (numbers, floats, etc).
License
The project is licensed under the MIT license.