Prints the value under specified keys or indexes of the YAML file.

yaml

#!/usr/bin/env ruby
require 'yaml'

def usage
  puts <<-USAGE
Usage: #{File.basename __FILE__} [options] file {keys|indexes}

Prints the value under specified keys or indexes of the YAML file.

Options:
  -h, --help         Show this message and exit.

  USAGE
end

while true
  case ARGV.first
  when "-h", "--help"
    usage
    exit
  else
    break
  end
end
file = ARGV.shift
result = YAML.load(File.read(file))
until ARGV.empty?
  key = ARGV.shift
  old_result = result
  result =
    case result
    when Array then begin result[Integer(key)] rescue nil end
    when Hash then result[key]
    end
  if result.nil? then abort %(no key #{key} found in:\n#{old_result.to_yaml}); end
end
puts(
  case result
  when Hash then result.to_yaml
  when Array then "[#{result.join(", ")}]"
  else result
  end
)