How can I change the text color in the windows command prompt

Question

I have a command line program, which outputs logging to the screen.

I want error lines to show up in red. Is there some special character codes I can output to switc

Answer 1

I've authored a small cross-platform gem that handles this seamlessly running on Windows or POSIX-systems, under both MRI and JRuby.

It has no dependencies, and uses ANSI codes on POSIX systems, and either FFI (JRuby) or Fiddler (MRI) for Windows.

To use it, simply:

gem install color-console

ColorConsole provides methods for outputting lines of text in different colors, using the Console.write and Console.puts functions.

require 'color-console'

Console.puts "Some text"                    # Outputs text using the current  console colours
Console.puts "Some other text", :red        # Outputs red text with the current background
Console.puts "Yet more text", nil, :blue    # Outputs text using the current foreground and a blue background

# The following lines output BlueRedGreen on a single line, each word in the appropriate color
Console.write "Blue ", :blue
Console.write "Red ", :red
Console.write "Green", :green

Visit the project home page at https://github.com/agardiner/color-console for more details.