scaint

# mv prefix_filename.txt filename.txt
find -type f | sed 's/prefix_\(.\+\)/mv \0 \1/' | sh

scaint

count = 1
сount = 2

count # => 1

local_variables # => [:o_0, :сount, :count, :_]

scaint

...

private
  def use_dsl(&block)
    proxy = Proxy.new(self, @api)
    proxy.call(&block)
  end
end

class Proxy < BasicObject

scaint

Date.current.beginning_of_year + 0xFF.days # => Sun, 13 Sep 2015

# 0001011000101110001011100000111011001110010111001111010011110100
# 1010011001110110011101001110111010010110110101101001011000001110
# 1010011000100110100101101000011001110100111101100100111011100110
# 1111010011101110100101101101011010010110111101000000101001001110
# 1111011011100110010011101000011010110110101101101010011001001110
# 110011101110010011111010001000101000011010011110

scaint

hash1 = {"x" => 1}

xml = hash1.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<hash>\n  <x type=\"integer\">1</x>\n</hash>\n"
hash2 = Hash.from_xml(xml) # => {"hash"=>{"x"=>1}}

hash1 == hash2 # => false

scaint

Date.today # => Mon, 10 Aug 2015
Date.current # => Sun, 09 Aug 2015

# File activesupport/lib/active_support/core_ext/date_and_time/calculations.rb, line 24
# def today?
#  to_date == ::Date.current
# end
Date.today.today? # => false

scaint

Object.class_eval { def self.private; Object; end }

def MyClass
  private
  
  def some_method
  end
end

MyClass.private_instance_methods.include? :some_method # => false

scaint

public.class_eval { def say_hello; 'Hello!'; end }

:ruby.say_hello # => "Hello!"

scaint

input_array = [1, 2, 1, 4, 1.0, 1r]

require 'set'
Set.new(input_array).to_a
# => [1, 2, 4, 1.0, (1/1)]

unique_elements = []
input_array.each { |el| unique_elements << el unless unique_elements.include?(el) }
unique_elements
# => [1, 2, 4]

scaint

# List of available dates you can see at https://static.rust-lang.org/dist/
curl -s https://static.rust-lang.org/rustup.sh | sudo sh -s -- --date="2015-03-25"