# Cl [![Build Status](https://travis-ci.org/svenfuchs/cl.svg?branch=master)](https://travis-ci.org/svenfuchs/cl) [![Code Climate](https://api.codeclimate.com/v1/badges/870e448eb8162d3e1ed7/maintainability)](https://codeclimate.com/github/svenfuchs/cl) [![Code Coverage](https://coveralls.io/repos/github/svenfuchs/cl/badge.svg?branch=master)](https://coveralls.io/github/svenfuchs/cl?branch=master) [![Gem Version](https://img.shields.io/gem/v/cl?cache=2019-08-10)](http://rubygems.org/gems/cl) [![Rubydocs](http://img.shields.io/badge/yard-docs-blue.svg)](http://rubydoc.info/github/svenfuchs/cl) OptionParser based CLI support for rapid CLI development in an object-oriented context. This library wraps Ruby's OptionParser for parsing your options under the hood, so you get all the goodness that the Ruby standard library provides. On top of that it adds a rich and powerful DSL for defining, validating, and normalizing options, as well as automatic and gorgeous help output (modeled after `gem --help`). Further documentation is available on [rubydoc.info](https://www.rubydoc.info/github/svenfuchs/cl) Examples in this README are included from [examples/readme](https://github.com/svenfuchs/cl/tree/master/examples/readme). More examples can be found in [examples](https://github.com/svenfuchs/cl/tree/master/examples). All examples are guaranteed to be up to date by the way of being [verified](https://github.com/svenfuchs/cl/blob/master/.travis.yml#L14) on CI. ## Table of Contents * [Basic Usage](#basic-usage) * [Command Registry](#command-registry) * [Runners](#runners) * [Command DSL](#command-dsl) * [Commands](#commands) * [Description, Summary, Examples](#description-summary-examples) * [Abstract](#abstract) * [Arguments](#arguments) * [Types](#types) * [Splat](#splat) * [Options](#options) * [Aliases](#aliases) * [Defaults](#defaults) * [Deprecations](#deprecations) * [Downcase](#downcase) * [Enum](#enum) * [Example](#example) * [Format](#format) * [Internal](#internal) * [Min and Max](#min-and-max) * [Negations](#negations) * [Note](#note) * [Secret](#secret) * [See Also](#see-also) * [Types](#types) * [Required Options](#required-options) * [Config Files](#config-files) * [Environment Variables](#environment-variables) ## Basic Usage ```ruby module Owners class Add < Cl::Cmd summary 'Add one or more owners to an existing owner group' description <<~str Use this command to add one or more owners to an existing owner group. [...] str args :owner opt '-t', '--to TO', 'An existing owner group' def run # implement adding the owner as given in `owner` (as well as `args`) # to the group given in `to` (as well as `opts[:to]`). p owner: owner, to: to, to?: to?, args: args, opts: opts end end end # Running this, e.g. using `bin/owners add one,two --to group` will instantiate the # class `Owners::Add`, and call the method `run` on it. # e.g. bin/owners # # args normally would be ARGV args = %w(add one --to group) Cl.new('owners').run(args) # Output: # # {:owner=>"one", :to=>"group", :to?=>true, :args=>["one"], :opts=>{:to=>"group"}} Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [owner] [options] # # Summary: # # Add one or more owners to an existing owner group # # Description: # # Use this command to add one or more owners to an existing # owner group. # # [...] # # Arguments: # # owner type: string # # Options: # # -t --to TO An existing owner group (type: string) # --help Get help on this command ``` ### Command Registry Commands are Ruby classes that extend the class `Cl::Cmd`. They register to a [Ruby class registry](https://github.com/svenfuchs/registry) in order to decouple looking up command classes from their Ruby namespace. For example: ```ruby module Cmd class One < Cl::Cmd end class Two < Cl::Cmd end end p Cl::Cmd[:one] # => Cmd::One p Cl::Cmd[:two] # => Cmd::Two ``` Commands auto register themselves with the underscored name of the last part of their class name (as seen in the example above). It is possible to ovewrite this key by manually registering the class, like so: ```ruby module One class Cmd < Cl::Cmd register :'cmd:one' end end ``` Be aware that if you derive a common base command class from `Cl::Cmd` it should be declared as `abstract` in order to unregister itself from the command registry. This will prevent the runner to consider it as a runnable command, and omit it from help output. See [abstract](#abstract) for details. ### Runners Runners lookup the command to execute from the registry, by checking the arguments given by the user for registered command keys. With the two command classes `One` and `Two` from the example above (and assuming that the executable that calls `Cl` is `bin/run`) the default runner would recognize and run the following commands: ``` $ bin/run one something else # instantiates One, passing the args array `["something", "else"]`, and calls the instance method `run` $ bin/run two # instantiates Two, passing an empty args arry `[]`, and calls the instance method `run` ``` The default runner also supports nested namespaces, and checks for command classes with keys separated by colons. For instance: ```ruby module Git class Pull < Cl::Cmd register :'git:pull' arg :branch def run p cmd: registry_key, args: args end end end # With this class registered (and assuming the executable that calls `Cl` is # `bin/run`) the default runner would recognize and run it: # # $ bin/run git:pull master # instantiates Git::Pull, and passes ["master"] as args # $ bin/run git pull master # does the same Cl.new('run').run(%w(git:pull master)) # Output: # # {:cmd=>:"git:pull", :args=>["master"]} Cl.new('run').run(%w(git pull master)) # Output: # # {:cmd=>:"git:pull", :args=>["master"]} ``` Runners are registered on the module `Cl::Runner`. It is possible to register custom runners, and use them by passing the option `runner` to `Cl.new`: ```ruby module Git class Pull < Cl::Cmd register :'git:pull' arg :branch def run p cmd: registry_key, args: args end end end # With this class registered (and assuming the executable that calls `Cl` is # `bin/run`) the default runner would recognize and run it: # # $ bin/run git:pull master # instantiates Git::Pull, and passes ["master"] as args # $ bin/run git pull master # does the same Cl.new('run').run(%w(git:pull master)) # Output: # # {:cmd=>:"git:pull", :args=>["master"]} Cl.new('run').run(%w(git pull master)) # Output: # # {:cmd=>:"git:pull", :args=>["master"]} ``` See `Cl::Runner::Default` for more details. There also is an experimental runner `:multi`, which supports rake-style execution of multiple commands at once, like so: ``` bin/rake db:drop production -f db:create db:migrate production -v 1 ``` See the example [rakeish](blob/master/examples/rakeish) for more details. ## Command DSL The DSL is defined on the class body. ### Commands Commands are classes that are derived from the base class `Cl::Cmd`. #### Description, Summary, Examples The description, summary, and examples are used in the help output. ```ruby module Owners class Add < Cl::Cmd summary 'Add one or more owners to an existing owner group' description <<~str Use this command to add one or more owners to an existing owner group. str examples <<~str Adding a single user to the group admins: owners add user --to admins Adding a several users at once: owners add one two three --to admins str end end Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Summary: # # Add one or more owners to an existing owner group # # Description: # # Use this command to add one or more owners to an existing # owner group. # # Options: # # --help Get help on this command # # Examples: # # Adding a single user to the group admins: # # owners add user --to admins # # Adding a several users at once: # # owners add one two three --to admins ``` #### Abstract Command base classes can be declared abstract in order to prevent them from being identified as a runnable command and to omit them from help output. This is only relevant if a command base class is registered. See [Command Registry](#command-registry) for details. ```ruby class Base < Cl::Cmd abstract end class Add < Base def run puts 'Success' end end Cl.new('owners').run(%w(add)) # Output: # # Success Cl.new('owners').run(%w(base)) # Output: # # Unknown command: base ``` ### Arguments Arguments can be declared like so: ```ruby arg :arg_name, description: 'arg description', type: :[array|string|integer|float|boolean] ``` This will define an `attr_accessor` on the `Cmd` class. I.e. in the following example the method `ownsers` will be available on the `Cmd` instance: ```ruby class Add < Cl::Cmd arg :owner def run p owner: owner end end Cl.new('owners').run(%w(add one)) # Output: # # {:owner=>"one"} ``` #### Types Arguments can have a type. Known types are: `:array`, `:string`, `:integer`, `:float`, `:boolean`. The type `:array` makes sure the argument accessible on the `Cmd` instance is a Ruby Array. (This currently only supports arrays of strings). If the option `sep` is given on the argument, then the argument value is split using this separator. ```ruby class Add < Cl::Cmd arg :owners, type: :array, sep: ',' def run p owners: owners end end Cl.new('owners').run(%w(add one,two)) # Output: # # {:owners=>["one", "two"]} ``` Other types cast the given argument to the expected Ruby type. ```ruby class Cmd < Cl::Cmd arg :one, type: :integer arg :two, type: :float arg :three, type: :boolean def run p [one.class, two.class, three.class] end end Cl.new('owners').run(%w(cmd 1 2.1 yes)) # Output: # # [Integer, Float, TrueClass] ``` #### Splat Array arguments support splats, modeled after Ruby argument splats. For example: ```ruby class Lft < Cl::Cmd arg :a, type: :array, splat: true arg :b arg :c def run p [a, b, c] end end class Mid < Cl::Cmd arg :a arg :b, type: :array, splat: true arg :c def run p [a, b, c] end end class Rgt < Cl::Cmd arg :a arg :b arg :c, type: :array, splat: true def run p [a, b, c] end end Cl.new('splat').run(%w(lft 1 2 3 4 5)) # Output: # # [["1", "2", "3"], "4", "5"] Cl.new('splat').run(%w(mid 1 2 3 4 5)) # Output: # # ["1", ["2", "3", "4"], "5"] Cl.new('splat').run(%w(rgt 1 2 3 4 5)) # Output: # # ["1", "2", ["3", "4", "5"]] ``` ### Options Declaring options can be done by calling the method `opt` on the class body. This will add the option, if given by the user, to the hash `opts` on the `Cmd` instance. It also defines a reader method that returns the respective value from the `opts` hash, and a predicate that will be true if the option has been given. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP', 'Target group to add owners to' def run p opts: opts, to: to, to?: to? end end Cl.new('owners').run(%w(add --to one)) # Output: # # {:opts=>{:to=>"one"}, :to=>"one", :to?=>true} Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Options: # # --to GROUP Target group to add owners to (type: string) # --help Get help on this command ``` Options optionally accept a block in case custom normalization is needed. Depending on the block's arity the following arguments are passed to the block: option value, option name, option type, collection of all options defined on the command. ```ruby class Add < Cl::Cmd # depending on its arity the block can receive: # # * value # * value, name # * value, name, type # * value, name, type, opts opt '--to GROUP' do |value| opts[:to] = "group-#{value}" end def run p to: to end end Cl.new('owners').run(%w(add --to one)) # Output: # # {:to=>"group-one"} ``` #### Aliases Options can have one or many alias names, given as a Symbol or Array of Symbols: ```ruby class Add < Cl::Cmd opt '--to GROUP', alias: :group def run # p opts: opts, to: to, to?: to?, group: group, group?: group? p opts: opts, to: to, to?: to? end end Cl.new('owners').run(%w(add --group one)) # Output: # # {:opts=>{:to=>"one", :group=>"one"}, :to=>"one", :to?=>true} ``` #### Defaults Options can have a default value. I.e. this value is going to be used if the user does not provide the option: ```ruby class Add < Cl::Cmd opt '--to GROUP', default: 'default' def run p to: to end end Cl.new('owners').run(%w(add)) # Output: # # {:to=>"default"} ``` #### Deprecations Options, and option alias name can be deprecated. For a deprecated option: ```ruby class Add < Cl::Cmd opt '--target GROUP', deprecated: 'Deprecated.' def run p target: target, deprecations: deprecations end end Cl.new('owners').run(%w(add --target one)) # Output: # # {:target=>"one", :deprecations=>{:target=>"Deprecated."}} ``` For a deprecated option alias name: ```ruby class Add < Cl::Cmd opt '--to GROUP', alias: :target, deprecated: :target def run p to: to, deprecations: deprecations end end Cl.new('owners').run(%w(add --target one)) # Output: # # {:to=>"one", :deprecations=>{:target=>:to}} ``` #### Downcase Options can be declared to be downcased. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP', downcase: true def run p to: to end end Cl.new('owners').run(%w(add --to ONE)) # Output: # # {:to=>"one"} ``` #### Enum Options can be enums (i.e. have known values). If an unknown values is given by the user the parser will reject the option, and print the help output for this command. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP', enum: %w(one two) def run p to: to end end Cl.new('owners').run(%w(add --to one)) # Output: # # {:to=>"one"} Cl.new('owners').run(%w(add --to unknown)) # Output: # # Unknown value: to=unknown (known values: one, two) # # Usage: owners add [options] # # Options: # # --to GROUP type: string, known values: one, two # --help Get help on this command ``` #### Example Options can have examples that will be printed in the help output. ```ruby class Add < Cl::Cmd opt '--to GROUP', example: 'group-one' end Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Options: # # --to GROUP type: string, e.g.: group-one # --help Get help on this command ``` #### Format Options can have a required format. If a value is given by the user that does not match the format then the parser will reject the option, and print the help output for this command. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP', format: /^\w+$/ def run p to: to end end Cl.new('owners').run(%w(add --to one)) # Output: # # {:to=>"one"} Cl.new('owners').run(['add', '--to', 'does not match!']) # Output: # # Invalid format: to (format: /^\w+$/) # # Usage: owners add [options] # # Options: # # --to GROUP type: string, format: /^\w+$/ # --help Get help on this command ``` #### Internal Options can be declared to be internal, hiding the option from the help output. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP' opt '--hidden', internal: true end Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Options: # # --to GROUP type: string # --help Get help on this command ``` #### Min and Max Options can have mininum and/or maximum values. If a value is given by the user that does not match the required min and/or max values then the parser will reject the option, and print the help output for this command. For example: ```ruby class Add < Cl::Cmd opt '--retries COUNT', type: :integer, min: 1, max: 5 def run p retries: retries end end Cl.new('owners').run(%w(add --retries 1)) # Output: # # {:retries=>1} Cl.new('owners').run(%w(add --retries 10)) # Output: # # Out of range: retries (min: 1, max: 5) # # Usage: owners add [options] # # Options: # # --retries COUNT type: integer, min: 1, max: 5 # --help Get help on this command ``` #### Negations Flags (boolean options) automatically allow negation using `--no-*` and `--no_*` using OptionParser's support for these. However, sometimes it can be convenient to allow other terms for negating an option. Flags therefore accept an option `negate` like so: ```ruby class Add < Cl::Cmd opt '--notifications', 'Send out notifications to the team', negate: %w(skip) def run p notifications? end end Cl.new('owners').run(%w(add --notifications)) # Output: # # true Cl.new('owners').run(%w(add --no_notifications)) # Output: # # false Cl.new('owners').run(%w(add --no-notifications)) # Output: # # false Cl.new('owners').run(%w(add --skip_notifications)) # Output: # # false Cl.new('owners').run(%w(add --skip-notifications)) # Output: # # false ``` #### Note Options can have a note that will be printed in the help output. ```ruby class Add < Cl::Cmd opt '--to GROUP', note: 'needs to be a group' end Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Options: # # --to GROUP type: string, note: needs to be a group # --help Get help on this command ``` #### Secret Options can be declared as secret. This makes it possible for client code to inspect if a given option is secret. Also, option values given by the user will be tainted, so client code can rely on this in order to, for example, obfuscate values from log output. ```ruby class Add < Cl::Cmd opt '--pass PASS', secret: true def run p( secret?: self.class.opts[:pass].secret?, tainted?: pass.tainted? ) end end Cl.new('owners').run(%w(add --pass pass)) # Output: # # {:secret?=>true, :tainted?=>true} ``` #### See Also Options can refer to documentation using the `see` option. This will be printed in the help output. For example: ```ruby class Add < Cl::Cmd opt '--to GROUP', see: 'https://docs.io/cli/owners/add' end Cl.new('owners').run(%w(add --help)) # Output: # # Usage: owners add [options] # # Options: # # --to GROUP type: string, see: https://docs.io/cli/owners/add # --help Get help on this command ``` #### Types Options can have a type. Known types are: `:array`, `:string`, `:integer`, `:float`, `:boolean`. The type `:array` allows an option to be given multiple times, and makes sure the value accessible on the `Cmd` instance is a Ruby Array. (This currently only supports arrays of strings). ```ruby class Add < Cl::Cmd opt '--to GROUP', type: :array def run p to end end Cl.new('owners').run(%w(add --to one --to two)) # Output: # # ["one", "two"] ``` Other types cast the given value to the expected Ruby type. ```ruby class Add < Cl::Cmd opt '--active BOOL', type: :boolean opt '--retries INT', type: :integer opt '--sleep FLOAT', type: :float def run p active: active.class, retries: retries.class, sleep: sleep.class end end Cl.new('owners').run(%w(add --active yes --retries 1 --sleep 0.1)) # Output: # # {:active=>TrueClass, :retries=>Integer, :sleep=>Float} ``` #### Required Options There are three ways options can be required: * using `required: true` on the option: the option itself is required to be given * using `requires: :other`on the option: the option requires another option to be given * using `required :one, [:two, :three]` on the class: either `one` or both `two` and `three` must be given For example, this simply requires the option `--to`: ```ruby class Add < Cl::Cmd opt '--to GROUP', required: true def run p to: to end end Cl.new('owners').run(%w(add --to one)) # Output: # # {:to=>"one"} Cl.new('owners').run(%w(add)) # Output: # # Missing required option: to # # Usage: owners add [options] # # Options: # # --to GROUP type: string, required # --help Get help on this command ``` This will make the option `--retries` depend on the option `--to`: ```ruby class Add < Cl::Cmd opt '--to GROUP' opt '--other GROUP', requires: :to def run p to: to, other: other end end Cl.new('owners').run(%w(add --to one --other two)) # Output: # # {:to=>"one", :other=>"two"} Cl.new('owners').run(%w(add --other two)) # Output: # # Missing option: to (required by other) # # Usage: owners add [options] # # Options: # # --to GROUP type: string # --other GROUP type: string, requires: to # --help Get help on this command ``` This requires either the option `--api_key` or both options `--username` and `--password` to be given: ```ruby class Add < Cl::Cmd # read DNF, i.e. "token OR user AND pass required :token, [:user, :pass] opt '--token TOKEN' opt '--user NAME' opt '--pass PASS' def run p token: token, user: user, pass: pass end end Cl.new('owners').run(%w(add --token token)) # Output: # # {:token=>"token", :user=>nil, :pass=>nil} Cl.new('owners').run(%w(add --user user --pass pass)) # Output: # # {:token=>nil, :user=>"user", :pass=>"pass"} Cl.new('owners').run(%w(add)) # Output: # # Missing options: token, or user and pass # # Usage: owners add [options] # # Options: # # Either token, or user and pass are required. # # --token TOKEN type: string # --user NAME type: string # --pass PASS type: string # --help Get help on this command ``` ### Config Files Cl automatically reads config files that match the given executable name (inspired by [gem-release](https://github.com/svenfuchs/gem-release)), stored either in the user directory or the current working directory. For example: ```ruby module Api class Login < Cl::Cmd opt '--username USER' opt '--password PASS' end end # bin/api CL.new('api').run(ARGV) # ~/api.yml login: username: 'someone' password: 'password' # ./api.yml login: username: 'someone else' ``` then running ``` $ bin/api login ``` instantiates `Api::Login`, and passes the hash ```ruby { username: 'someone else', password: 'password' } ``` as `opts`. Options passed by the user take precedence over defaults defined in config files. ### Environment Variables Cl automatically defaults options to environment variables that are prefixed with the given executable name (inspired by [gem-release](https://github.com/svenfuchs/gem-release)). ```ruby module Api class Login < Cl::Cmd opt '--username USER' opt '--password PASS' end end # bin/api CL.new('api').run(ARGV) ``` then running ``` $ API_USERNAME=someone API_PASSWORD=password bin/api login ``` instantiates `Api::Login`, and passes the hash ```ruby { username: 'someone', password: 'password' } ``` Options passed by the user take precedence over defaults given as environment variables, and environment variables take precedence over defaults defined in config files.