creating-powerful-command-line-tools-in-ruby.rb

require 'optionparser'

options = {}
printers = Array.new

OptionParser.new do |opts|
  opts.banner = "Usage: dfm [options][path]\nDefaults: dfm -xd ." + File::SEPARATOR
  opts.on("-f", "--filters FILTERS", Array, "File extension filters") do |filters|
    options[:filters] = filters
  end
  opts.on("-x", "--duplicates-hex", "Prints duplicate files by MD5 hexdigest") do |dh|
    printers << "dh"
  end
  opts.on("-d", "--duplicates-name", "Prints duplicate files by file name") do |dh|
    printers << "dn"
  end
  opts.on("-s", "--singles-hex", "Prints non-duplicate files by MD5 hexdigest") do |dh|
    printers << "sh"
  end
  opts.on("-n", "--singles-name", "Prints non-duplicate files by file name") do |dh|
    printers << "sn"
  end
end.parse!
#
# Usage: dfm [options] [path]
# Defaults: dfm -xd ./
# -f, --filters FILTERS            File extension filters
# -x, --duplicates-hex             Prints duplicate files by MD5 hexdigest
# -d, --duplicates-name            Prints duplicate files by file name
# -s, --singles-hex                Prints non-duplicate files by MD5 hexdigest
# -n, --singles-name               Prints non-duplicate files by file name

# Excerpt from https://github.com/leejarvis/slop
opts = Slop.parse do |o|
  o.string '-h', '--host', 'a hostname'
  o.integer '--port', 'custom port', default: 80
  o.bool '-v', '--verbose', 'enable verbose mode'
  o.bool '-q', '--quiet', 'suppress output (quiet mode)'
  o.bool '-c', '--check-ssl-certificate', 'check SSL certificate for host'
  o.on '--version', 'print the version' do
    puts Slop::VERSION
    exit
  end
end

ARGV #=> -v --host 192.168.0.1 --check-ssl-certificate

opts[:host]                 #=> 192.168.0.1
opts.verbose?               #=> true
opts.quiet?                 #=> false
opts.check_ssl_certificate? #=> true

opts.to_hash  #=> { host: "192.168.0.1", port: 80, verbose: true, quiet: false, check_ssl_certificate: true }

x = {"hello" => "world", this: {"apple" => 4, tastes: "delicious"}}

require 'json'
puts x.to_json
# {"hello":"world","this":{"apple":4,"tastes":"delicious"}}

puts JSON.pretty_generate( x )
# {
#   "hello": "world",
#   "this": {
#     "apple": 4,
#     "tastes": "delicious"
#   }
# }

require 'yaml'
puts x.to_yaml
# ---
# hello: world
# :this:
#   apple: 4
#   :tastes: delicious

STDERR.puts "Oops! You broke it!"

favorite = "Superman"
printf "Who is your favorite hero [Superman]/Batman/Wonder Woman?"
input = gets.chomp
favorite = input unless input.empty?

require 'highline/import'
favorite = ask("Who is your favorite hero Superman/Batman/Wonder Woman?") {|question|
  question.in = ["Superman", "Batman", "Wonder Woman"]
  question.default = "Superman"
}

editor = "sublime" # your preferred editor here
exec "#{editor} #{RbConfig.method(:ruby).source_location[0]}"

require 'mkmf'
MakeMakefile::Logging.instance_variable_set(:@log, File.open(File::NULL, 'w'))
executable = MakeMakefile.find_executable('clear') # or whatever executable you're looking for