cli~amberframework
Crystal CLI
Yet another Crystal library for building command-line interface applications.
Installation
Add this to your application's shard.yml
:
dependencies:
cli:
github: mosop/cli
Code Samples
Option Parser
class Hello < Cli::Command
class Options
bool "--bye"
arg "to"
end
def run
if args.bye?
print "Goodbye"
else
print "Hello"
end
puts " #{args.to}!"
end
end
Hello.run %w(world) # prints "Hello, world!"
Hello.run %w(--bye world) # prints "Goodbye, world!"
Subcommand
class Polygon < Cli::Supercommand
command "triangle", default: true
class Triangle < Cli::Command
def run
puts 3
end
end
class Square < Cli::Command
def run
puts 4
end
end
class Hexagon < Cli::Command
def run
puts 6
end
end
end
Polygon.run %w(triangle) # prints "3"
Polygon.run %w(square) # prints "4"
Polygon.run %w(hexagon) # prints "6"
Polygon.run %w() # prints "3"
Replacing
class New < Cli::Command
def run
puts "new!"
end
end
class Obsolete < Cli::Command
replacer_command New
end
Obsolete.run # prints "new!"
Inheritance
abstract class Role < Cli::Command
class Options
string "--name"
end
end
class Chase < Cli::Supercommand
class Mouse < Role
def run
puts "#{options.name} runs away."
end
end
class Cat < Role
def run
puts "#{options.name} runs into a wall."
end
end
end
Chase.run %w(mouse --name Jerry) # prints "Jerry runs away."
Chase.run %w(cat --name Tom) # prints "Tom runs into a wall."
Help
class Call < Cli::Command
class Help
header "Receives an ancient message."
footer "(C) 20XX mosop"
end
class Options
arg "message", desc: "your message to call them", required: true
bool "-w", not: "-W", desc: "wait for response", default: true
help
end
end
Call.run %w(--help)
Output:
call [OPTIONS] MESSAGE
Receives an ancient message.
Arguments:
MESSAGE (required) your message to call them
Options:
-w wait for response
(default: true)
-W disable -w
-h, --help show this help
(C) 20XX mosop
Versioning
class Command < Cli::Supercommand
version "1.0.0"
class Options
version
end
end
Command.run %w(-v) # prints 1.0.0
Shell Completion
class TicketToRide < Cli::Command
class Options
string "--by", any_of: %w(train plane taxi)
arg "for", any_of: %w(kyoto kanazawa kamakura)
end
end
puts TicketToRide.generate_bash_completion
# or
puts TicketToRide.generate_zsh_completion
Usage
require "cli"
and see:
Want to Do
- Application-Level Logger
- I18n
Release Notes
See Releases.