How to Use Ruby to Colorize the Text Output to a Terminal

How can I use Ruby to colorize the text output to a terminal?

Colorize is my favorite gem! :-)

Check it out:

https://github.com/fazibear/colorize

Installation:

gem install colorize

Usage:

require 'colorize'

puts "I am now red".red
puts "I am now blue".blue
puts "Testing".yellow

How to output my ruby commandline text in different colours

I found this article describing a very easy way to write coloured texts to the console. The article describes this little example which seems to do the trick (I took the liberty to improve it slightly):

def colorize(text, color_code)
  "\e[#{color_code}m#{text}\e[0m"
end

def red(text); colorize(text, 31); end
def green(text); colorize(text, 32); end

# Actual example
puts 'Importing categories [ ' + green('DONE') + ' ]'
puts 'Importing tags       [' + red('FAILED') + ']'

Best seems to define some of the colours. You can extent the example when you need also different background colours (see bottom of article).

When using Window XP, the author mentions the requirement of a gem called win32console.

How do I print / puts with color?

Do you mean in the context of irb? If so, I'd suggest Wirble to colourize your output.

How can I preserve output color when executing a process in Ruby?

Kernel.exec() gets me the solution I want (colored rspec output), but it does so by replacing my ruby script process with the rspec process. That means I can't do anything with the output or run anything after the rspec call.

That's acceptable in my particular situation, but less than ideal as a general solution. So I'd like a better answer if available.

Ruby on Rails - How to print log messages in color

Basically what you want to do is embed ANSI escape sequences for color into your debug strings, just like you would in a regular Ruby program. There are several ways to go about this:

1. Use the rainbow gem, which allows you to do this:

   require 'rainbow'
Rails.logger.debug(Rainbow("This message is Green").green)

   or require the mixin to add methods directly to the string class:

   Updated March 2021: The Rainbow Gem API has changed. Use this now:

   require 'rainbow/refinement'
using Rainbow
Rails.logger.debug("This is Green - ".green + "This is Blue".blue)


   Previous Version (for posterity):

   require 'rainbow/ext/string'
Rails.logger.debug("This is Green - ".green + "This is Blue".blue)


   End Update

   The Rainbow gem will automatically add the beginning and ending escape sequences to the string.

2. Use the colorize gem, which does the same thing as the rainbow mixin to the String class:

   require 'colorize'
Rails.logger.debug("This is Green - ".green + "This is Blue".blue)

3. Put the escape sequences in yourself, using something like this:

   Rails.logger.debug("\033[32mThis message is Green\033[0m")

4. Write your own extension to the String class. See this answer or this answer for an example.

For more ideas, see How can I use Ruby to colorize the text output to a terminal?

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