Execution of shell (bash) code in Ruby scripts. http://makandracards.com/makandra/1243-execution-of-shell-code-in-ruby-scripts

example.rb

#1: %x{ } – quick and easy
name = 'ls'
result = `which #{name}` # or result = %x{which #{name}}

#2: system – when you want to know how it went
result = system 'cp', '/full/path/to/my_file', '/target/directory'
if result.nil?
  puts "Error was #{$?}"
elsif result
  puts "You made it!"
end

#3: exec – the last thing you do
puts "Creating directory..."
exec 'mkdir', 'new_directory'
# the code here and below will never be read

#4: spawn – gives you a good level of control
spawn(:name => 'development', 'echo hello world')

#5: open3 – for those who want to control everything