Clamp::Completer

Automatically generate shell auto-completion scripts for Ruby command-line tools built using the clamp gem.

Installation

Add this line to your application's Gemfile:

gem 'clamp-completer'

Or install it yourself as:

$ gem install clamp-completer

Usage

Require the clamp/completer and in your application's root command, add a subcommand:

require 'clamp/completer'

Clamp do
  subcommand "complete", "shell autocompletions", Clamp::Completer.new(self)
end

This will add a complete subcommand:

$ your_app complete zsh
$ your_app complete bash

You can redirect the output to a static file or load the output directly into the running environment:

# zsh / bash:
$ source <(your_app complete)
# or for the macOs preinstalled bash version:
$ source /dev/stdin <<<"$(your_app complete bash)"

Customizing completions

Currently, subcommand completions and flag-type options defined through option '--debug', :flag, 'enable debug' should work correctly out-of-the-box. For options that take parameters, such as file paths or a predefined set of words, you can define methods on your command classes that will be used to determine how the values should be completed:

Clamp do
  option '--config', 'YAML_FILE', "configuration YAML file path"

  def complete_yaml_file # name derived from the YAML_FILE argument description
    { glob: '*.yml' }
  end
end

Clamp do
  option '--role', 'ROLE_NAME', "node role"

  def complete_role # name derived from the attribute name
    "master worker" # will add "master" and "worker" as completion responses when you do: your_app --role <tab>
  end
end

Completion method response types

String

A space separated string of possible values for the option

Symbol

Currently known symbols:

• :dirs will complete directory names
• :files will complete file names
• :hosts will complete known host names

Hash

Much like the Symbols, but returned in Hash format to enable passing options:

• { glob: '*.yml' } will complete files endinging with .yml
• { command: 'cut -d':' -f1 /etc/passwd' } will run a command to get completion candidates, in this case the usernames from /etc/password

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/clamp-completer.