Command-Option-Argument

Yet another parser for command line options.

What is it?

COA is a parser for command line options that aim to get maximum profit from formalization your program API. Once you write definition in terms of commands, options and arguments you automaticaly get:

• Command line help text

• Program API for use COA-based programs as modules

• Shell completion

Other features

• Rich types for options and arguments, such as arrays, boolean flags and required

• Commands can be async throught using promising (powered by Q)

• Easy submoduling some existing commands to new top-level one

• Combined validation and complex parsing of values

TODO

• Localization

• Shell-mode

• Configs

• Aliases

• Defaults

Examples

require('coa').Cmd() // main (top level) command declaration
    .name(process.argv[1]) // set top level command name from program name
    .title('My awesome command line util') // title for use in text messages
    .helpful() // make command "helpful", i.e. options -h --help with usage message
    .opt() // add some option
        .name('version') // name for use in API
        .title('Version') // title for use in text messages
        .short('v') // short key: -v
        .long('version') // long key: --version
        .flag() // for options without value
        .act(function(opts) { // add action for option
            // return message as result of action
            return JSON.parse(require('fs').readFileSync(__dirname + '/package.json'))
                .version;
        })
        .end() // end option chain and return to main command
    .cmd().name('subcommand').apply(require('./subcommand').COA).end() // load subcommand from module
    .cmd() // inplace subcommand declaration
        .name('othercommand').title('Awesome other subcommand').helpful()
        .opt()
            .name('input').title('input file, required')
            .short('i').long('input')
            .val(function(v) { // validator function, also for translate simple values
                return require('fs').createReadStream(v) })
            .req() // make option required
            .end() // end option chain and return to command
        .end() // end subcommand chain and return to parent command
    .run(process.argv.slice(2)); // parse and run on process.argv

// subcommand.js
exports.COA = function() {
    this
        .title('Awesome subcommand').helpful()
        .opt()
            .name('output').title('output file')
            .short('o').long('output')
            .output() // use default preset for "output" option declaration
            .end()
};

API reference

Cmd

Command is a top level entity. Commands may have options and arguments.

Cmd.api

Returns object containing all its subcommands as methods to use from other programs. @returns {Object}

Cmd.name

Set a canonical command identifier to be used anywhere in the API. @param String _name command name @returns COA.Cmd this instance (for chainability)

Cmd.title

Set a long description for command to be used anywhere in text messages. @param String _title command title @returns COA.Cmd this instance (for chainability)

Cmd.cmd

Create new or add existing subcommand for current command. @param COA.Cmd [cmd] existing command instance @returns COA.Cmd new or added subcommand instance

Cmd.opt

Create option for current command. @returns COA.Opt new option instance

Cmd.arg

Create argument for current command. @returns COA.Opt new argument instance

Cmd.act

Add (or set) action for current command. @param Function act action function, invoked in the context of command instance and has the parameters: - Object opts parsed options - Array args parsed arguments - Object res actions result accumulator It can return rejected promise by Cmd.reject (in case of error) or any other value treated as result. @param {Boolean} [force=false] flag for set action instead add to existings @returns COA.Cmd this instance (for chainability)

Cmd.apply

Apply function with arguments in context of command instance. @param Function fn @param Array args @returns COA.Cmd this instance (for chainability)

Cmd.comp

Set custom additional completion for current command. @param Function fn completion generation function, invoked in the context of command instance. Accepts parameters: - Object opts completion options It can return promise or any other value treated as result. @returns COA.Cmd this instance (for chainability)

Cmd.helpful

Make command "helpful", i.e. add -h --help flags for print usage. @returns COA.Cmd this instance (for chainability)

Cmd.completable

Adds shell completion to command, adds "completion" subcommand, that makes all the magic. Must be called only on root command. @returns COA.Cmd this instance (for chainability)

Cmd.usage

Build full usage text for current command instance. @returns String usage text

Cmd.run

Parse arguments from simple format like NodeJS process.argv and run ahead current program, i.e. call process.exit when all actions done. @param Array argv @returns COA.Cmd this instance (for chainability)

Cmd.invoke

Invoke specified (or current) command using provided options and arguments. @param String|Array cmds subcommand to invoke (optional) @param Object opts command options (optional) @param Object args command arguments (optional) @returns Q.Promise

Cmd.reject

Return reject of actions results promise. Use in .act() for return with error. @param Object reason reject reason You can customize toString() method and exitCode property of reason object. @returns Q.promise rejected promise

Cmd.end

Finish chain for current subcommand and return parent command instance. @returns COA.Cmd parent command

Opt

Option is a named entity. Options may have short and long keys for use from command line. @namespace @class Presents option

Opt.name

Set a canonical option identifier to be used anywhere in the API. @param String _name option name @returns COA.Opt this instance (for chainability)

Opt.title

Set a long description for option to be used anywhere in text messages. @param String _title option title @returns COA.Opt this instance (for chainability)

Opt.short

Set a short key for option to be used with one hyphen from command line. @param String _short @returns COA.Opt this instance (for chainability)

Opt.long

Set a short key for option to be used with double hyphens from command line. @param String _long @returns COA.Opt this instance (for chainability)

Opt.flag

Make an option boolean, i.e. option without value. @returns COA.Opt this instance (for chainability)

Opt.arr

Makes an option accepts multiple values. Otherwise, the value will be used by the latter passed. @returns COA.Opt this instance (for chainability)

Opt.req

Makes an option req. @returns COA.Opt this instance (for chainability)

Opt.only

Makes an option to act as a command, i.e. program will exit just after option action. @returns COA.Opt this instance (for chainability)

Opt.val

Set a validation (or value) function for argument. Value from command line passes through before becoming available from API. Using for validation and convertion simple types to any values. @param Function _val validating function, invoked in the context of option instance and has one parameter with value from command line @returns COA.Opt this instance (for chainability)

Opt.def

Set a default value for option. Default value passed through validation function as ordinary value. @param Object _def @returns COA.Opt this instance (for chainability)

Opt.input

Make option value inputting stream. It's add useful validation and shortcut for STDIN. @returns {COA.Opt} this instance (for chainability)

Opt.output

Make option value outputing stream. It's add useful validation and shortcut for STDOUT. @returns COA.Opt this instance (for chainability)

Opt.act

Add action for current option command. This action is performed if the current option is present in parsed options (with any value). @param Function act action function, invoked in the context of command instance and has the parameters: - Object opts parsed options - Array args parsed arguments - Object res actions result accumulator It can return rejected promise by Cmd.reject (in case of error) or any other value treated as result. @returns COA.Opt this instance (for chainability)

Opt.comp

Set custom additional completion for current option. @param Function fn completion generation function, invoked in the context of command instance. Accepts parameters: - Object opts completion options It can return promise or any other value treated as result. @returns COA.Opt this instance (for chainability)

Opt.end

Finish chain for current option and return parent command instance. @returns COA.Cmd parent command

Arg

Argument is a unnamed entity. From command line arguments passed as list of unnamed values.

Arg.name

Set a canonical argument identifier to be used anywhere in text messages. @param String _name argument name @returns COA.Arg this instance (for chainability)

Arg.title

Set a long description for argument to be used anywhere in text messages. @param String _title argument title @returns COA.Arg this instance (for chainability)

Arg.arr

Makes an argument accepts multiple values. Otherwise, the value will be used by the latter passed. @returns COA.Arg this instance (for chainability)

Arg.req

Makes an argument req. @returns COA.Arg this instance (for chainability)

Arg.val

Set a validation (or value) function for argument. Value from command line passes through before becoming available from API. Using for validation and convertion simple types to any values. @param Function _val validating function, invoked in the context of argument instance and has one parameter with value from command line @returns COA.Arg this instance (for chainability)

Arg.def

Set a default value for argument. Default value passed through validation function as ordinary value. @param Object _def @returns COA.Arg this instance (for chainability)

Arg.output

Make argument value outputing stream. It's add useful validation and shortcut for STDOUT. @returns COA.Arg this instance (for chainability)

Arg.comp

Set custom additional completion for current argument. @param Function fn completion generation function, invoked in the context of command instance. Accepts parameters: - Object opts completion options It can return promise or any other value treated as result. @returns COA.Arg this instance (for chainability)

Arg.end

Finish chain for current option and return parent command instance. @returns COA.Cmd parent command