How to output my ruby commandline text in different colours

Question

How can I make the puts commands I output from a commandline based ruby program colour? I would appreciated any references to how I call each different colour also.

Lets

Answer 1

Check out the following libraries:

http://www.gnu.org/software/ncurses/ncurses.html

https://github.com/JEG2/highline

http://coderay.rubychan.de/

Answer 2

My suggestion: The paint gem. It does not enforce string extensions and supports 256-colors (with fall-back mode for non-256-color terminals).

Usage:

puts Paint["I'm blue!", :blue]
puts Paint["I'm dark blue if your terminal supports it!", "#000044"]

Answer 3

Check out the cli-colorize gem: http://github.com/stjohncj/cli-colorize/blob/master/README.rdoc

Answer 4

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.

Answer 5

I've created something like this:

begin
   require 'Win32/Console/ANSI' if PLATFORM =~ /win32/
rescue LoadError
   raise 'You must gem install win32console to use color on Windows'
end

class Colors
   COLOR1 = "\e[1;36;40m"
   COLOR2 = "\e[1;35;40m"
   NOCOLOR = "\e[0m"
   RED = "\e[1;31;40m"
   GREEN = "\e[1;32;40m"
   DARKGREEN = "\e[0;32;40m"
   YELLOW = "\e[1;33;40m"
   DARKCYAN = "\e[0;36;40m"
end

class String
   def color(color)
      return color + self + Colors::NOCOLOR
   end
end

Now you can just use another method of String:

"Hello World".color(Colors::DARKGREEN)

To know all the colors just execute this:

begin
  require 'Win32/Console/ANSI' if PLATFORM =~ /win32/
rescue LoadError
  raise 'You must gem install win32console to use color on Windows'
end

[0, 1, 4, 5, 7].each do |attr|
  puts '----------------------------------------------------------------'
  puts "ESC[#{attr};Foreground;Background"
  30.upto(37) do |fg|
    40.upto(47) do |bg|
      print "\033[#{attr};#{fg};#{bg}m #{fg};#{bg}  "
    end
  puts "\033[0m"
  end
end

Answer 6

Thought I'd add another solution as it does things a little differently and includes more colour codes:

First some examples...

Using method chaining:

String.include(AnsiTextStyles)

puts "How are you?".blue.bold + " " + 'I am good!'.red.bold
puts '%s %s' % ["How are you?".blue.bold, 'I am good!'.red.bold]

Using the style method and applying multiple attributes:

puts "How are you?".style(:red)
puts 'I am good!'.style(:blue, :underline)
puts 'Good to hear'.style([:bg_magenta, :blink])

This can be used to store style attributes in some manner to apply later:

text_styles = {
    red_bold:       [:red, :bold],
    blue_underline: [:blue, :underline],
    pretty:         [:bg_magenta, :blink],
  }

text_styles.each do |name, style|
  styled_text = "Text styled multiple ways".style(style)
  puts "%s: %s" % [name, styled_text]
end

I've given a few more examples on this gist I created and expanded the code to include refinements so that modifications to String are scoped.

This is the basic code:

module AnsiTextStyles

  TEXT_ATTRIBUTES = {
      # text properties
      none: 0, # turn off all attributes
      bold: 1, bright: 1, # these do the same thing really
      italic: 3, underline: 4, blink: 5,
      reverse: 7, # swap foreground and background colours
      hide: 8, # foreground color same as background

      # foreground colours
      black: 30, grey: 90, lt_grey: 37, :white => 97,
      red: 31, lt_red: 91, 
      green: 32, lt_green: 92,
      dk_yellow: 33, brown: 33, yellow: 93,
      blue: 34, lt_blue: 94,
      magenta: 35, pink: 95, lt_magenta: 95,
      cyan: 36, lt_cyan: 96,
      default: 39,

      # background colours
      bg_black: 40, bg_grey: 100, bg_lt_grey: 47, bg_white: 107,
      bg_red: 41, bg_lt_red: 101,
      bg_green: 42, bg_lt_green: 102,
      bg_dk_yellow: 43, bg_brown: 43, bg_yellow: 103,
      bg_blue: 44, bg_lt_blue: 104,
      bg_magenta: 45, bg_pink: 105, bg_lt_magenta: 105,
      bg_cyan: 46, bg_lt_cyan: 106,
    }

  def self.text_attributes
    TEXT_ATTRIBUTES.keys
  end

  # applies the text attributes to the current string
  def style(*text_attributes)
    codes = TEXT_ATTRIBUTES.values_at(*text_attributes.flatten).compact
    "\e[%sm%s\e[m" % [codes.join(';'), self.to_s]
  end

end