Clipper - Pure Command Line Arguments Parser

Clipper is a small wrapper around the standard OptionParser with these conceptual changes:

1. It supports positional arguments (commands or positional parameters).
2. It simply returns a hash of all the expected flags and positional arguments.
3. It is designed to let you separate the command line parsing from your actual implementation.
4. It does not concern itself with any help or usage strings - you need to bring your own.
5. It stays out of your way.

Clipper does not assume anything about how you wish to build your command line utility, or how you wish to display its usage.

Installation

Add the dependency to your shard.yml:

dependencies:
  clipper:
    github: dannyben/clipper

Then run shards install

Usage

Clipper contains three methods only:

• #flag - specify which flags are expected.
• #arg - specify which positional arguments are expected.
• #parse - convert the ARGV array to a Hash of all expected and actual options.

require "clipper"

# Create a clipper instance:
clipper = Clipper.new

# Specify which flags are expected, using one of these general patterns:
clipper.flag "--cache", "-c"
clipper.flag "--long-only"
clipper.flag "--port PORT", "-p PORT", default: "3000"

# If you care about any positional arguments, give them a name by using this
# pattern:
clipper.arg "command"

# Finally, parse the options:
options = clipper.parse
# => {"--cache" => false, "--long-only" => false, 
# =>  "--port" => "3000", "command" => false}

options = clipper.parse ["--cache", "-p", "4567"]
# => {"--cache" => true, "--long-only" => false,
# =>  "--port" => "4567", "command" => false}

options = clipper.parse ["download"]
# => {"--cache" => true, "--long-only" => false,
# =>  "--port" => "4567", "command" => "download"}

For more advanced examples, see the examples folder.