There are six ways to execute shell commands in ruby.

Here are examples for perhaps the two most useful:

- Backticks
    stdout = `touch some_file` # Runs shell command 'touch' with parameter 'some_file'
  With this you get the command's standard output as a string.

- Open3#popen3
    stdin, stdout, stderr = Open3.popen3('touch some_file')
  Use this if you need to catch the standard error stream.
  To convert a stream to a string, you can do this:
    err_string = stderr.read

More info at:
  http://zhangxh.net/programming/ruby/6-ways-to-run-shell-commands-in-ruby/