wteuber

module Foo
  include ActiveSupport::Configurable
  class << self
    def configure
      yield config
    end
  end
end

Foo.configure do |config|

wteuber

# cat, print file.bin's binary content
 cat file.bin
 # => 

# DUMP - convert binary content to hex string
 xxd -p file.bin | tr -d '\n'
 # => 48656c6c6f20576f726c640a

# RESTORE - convert hex string to binary content
 echo 48656c6c6f20576f726c640a | xxd -r -p

wteuber

# DUMP
mkdir -p ~/backup
dpkg --get-selections > ~/backup/Package.list
sudo cp -R /etc/apt/sources.list* ~/backup/
sudo apt-key exportall > ~/backup/Repo.keys

# RESTORE
sudo apt-key add ~/backup/Repo.keys
sudo cp -R ~/backup/sources.list* /etc/apt/
sudo apt-get update

wteuber

params = Hash[[*'a'..'j'].zip([*1..10])] # => {"a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5, "f"=>6, "g"=>7, "h"=>8, "i"=>9, "j"=>10}
slice_keys = ['a','f','g']

filter = -> (key, _) { slice_keys.include?(key) }
slice = params.select &filter
params.delete_if &filter

slice   # => {"a"=>1, "f"=>6, "g"=>7}
params  # => {"b"=>2, "c"=>3, "d"=>4, "e"=>5, "h"=>8, "i"=>9, "j"=>10}

wteuber

require 'digest'
result = Hash.new() { |hash, key| hash[key] = [] }
Dir['**/*'].each do |file|
  if File.file?(file)
    result[Digest::MD5.new.file(file).to_s] << file
  end
end
result

wteuber

ls **/en.yml **/de.yml | grep -v spec| tar -czf archive.tgz -T -

wteuber

foo = Namespace::To::Module.instance_method(:foo)
obj.class.send(:define_method, :foo, foo)

wteuber

ary.inject(Hash.new(0)) { |total, e| total[e] += 1 ;total}

wteuber

#!/usr/bin/env ruby

require 'yaml'

class Hash
  def deep_reject(&blk)
    self.dup.deep_reject!(&blk)
  end
  def deep_reject!(&blk)
    self.each do |k, v|

wteuber

for f in `git ls-files "*.rb"`; do ruby -c $f | grep -v "Syntax OK" ; done