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

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