Code & Clay – Notes to self. Mainly Ruby/Rails.

Enhanced shell scripting with Ruby

From Dev_Dungeon:

Ruby is a better Perl and in my opinion is an essential language for system administrators. If you are still writing scripts in Bash, I hope this inspires you to start integrating Ruby in to your shell scripts. I will show you how you can ease in to it and make the transition very smoothly.

I’ve learnt a few things from the article:

Debug output, and anything that does not belong in the output of the application should go to STDERR and only data that should be piped to anothe application or stored should go to STDOUT

There’s ARGF in addition to ARGV.

I can ask the user for a password without the password being echoed back to the terminal:

require 'io/console'

# The prompt is optional
password = IO::console.getpass "Enter Password: "
puts "Your password was #{password.length} characters long."

I can check for return codes and errors via the $? object.

I can trap interrupt signals with Signal.trap().


Signal.trap("SIGINT") {
    puts 'Caught a CTRL-C / SIGINT. Shutting down cleanly.'

puts 'Running forever until CTRL-C / SIGINT signal is recieved.'
while true do end

If you really want to get to grips with Ruby development and gain a solid understanding of Object Oriented Design, I thoroughly recommend Sandi Metz's Practical Object Oriented Design in Ruby. It's the perfect introduction to OOP and pragmatic Ruby. You can buy it here.

“Meticulously pragmatic and exquisitely articulate, Practical Object Oriented Design in Ruby makes otherwise elusive knowledge available to an audience which desperately needs it. The prescriptions are appropriate both as rules for novices and as guidelines for experienced professionals.”

Katrina Owen, Creator, Exercism

Essential Reading: Learn Rails 6