crap 💩

A Crystal library to help write command-line applications with programmable completion, inspired by Rust's clap crate and Go's cobra.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     crap:
       github: bjjb/crap
   

2. Run shards install

The project is developed on GitLab, but mirrored on GitHub.

Usage

Here's a fairly basic example: a clone of the echo(1) command/builtin.

require "crap"

Crap.parse do
  name "echo"
  summary "Write arguments to the standard output."
  description <<-DESC
    Display the args, separated by a single space character and followed by a
    newline, on the standard output. Returns success unless a write error
    occurs.
  DESC
  option "-n", "don't append a newline"
  action do |args|
    print args.join(" ")
    puts unless option?("n")
  end
end

You can build arbitrarily complex command-line apps by using sub-commands (Crap#crap). See the examples folder for some inspiration.

Development

There are no special dependencies; develop it as you would any Crystal project.

Related projects

• cobra - a great CLI-helper package in Go
• clap - a great CLI helper package in Rust
• crapi - a compatible Crystal shard to build apps from OpenAPI specs

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new merge request

Contributors

• JJ Buckley - creator and maintainer