How to vertically align stdout text in Ruby (like Rails)

Question

I am trying to create a CLI application and I want to output text to the console. I cannot figure out how to format how I want.

When you type rails new app, you get this output:

  create  tmp/cache
  create  tmp/cache/assets
  create  vendor/assets/javascripts
  create  vendor/assets/javascripts/.keep
  create  vendor/assets/stylesheets
  create  vendor/assets/stylesheets/.keep
     run  bundle install

How can I write my output to make sure all the commands are vertically aligned like that?

PS. I am using Thor is that matters.

Thanks

Answer 1

I think you're overthinking this. They are just printing out lines of text with spacing in between.

puts "  create  tmp/cache"
puts "  create  tmp/cache/assets"
# ...

will output exactly the same way.

There is a function in Ruby that would help out with this a tiny bit (String#rjust), which will pad the string with spaces on the left. So if you want your first column to be 10 characters wide, you can rjust the strings with a value of 10 and it will align them to the right. If you're iterating through a hash, for example, you might run the following code:

hash = { "hello" => "world", "foo" => "bar" }
hash.each do |key, value|
  puts "#{key.rjust(7)}  #{value}"
end
#  hello  world
#    foo  bar