Very often I have to implement console scripts (because of my laziness, for boring processes optimization). Many of them write some information to the output, show process status or display results of work. Anyway, it’s very wearisome action to read script output, and I want to highlight most important things: errors in red, successfully finished steps in green color, etc. And it is a case when ANSI escape sequences could help. They are supported by the most terminals, including VT100 (btw, Windows NT family console does not support it, but I will back to this issue later).
For the beginning, let’s examine ANSI escape sequence structure. It starts with ESC symbol (ASCII-code 27), following by left square bracket [. There are one or more numbers separated by semicolon ; with a letter at the end appear after it.
I will not describe all possible codes, anybody who wishes could find them in Wikipedia. The sequence with m letter at the end is used to change foreground and background colors. In general situation it looks like: ESC[31m, where 31 sets red color as foreground. Here the table with codes which supported by most terminals:
| Code | Effect |
|---|---|
| 0 | Turn off all attributes |
| 1 | Set bright mode |
| 4 | Set underline mode |
| 5 | Set blink mode |
| 7 | Exchange foreground and background colors |
| 8 | Hide text (foreground color would be the same as background) |
| 30 | Black text |
| 31 | Red text |
| 32 | Green text |
| 33 | Yellow text |
| 34 | Blue text |
| 35 | Magenta text |
| 36 | Cyan text |
| 37 | White text |
| 39 | Default text color |
| 40 | Black background |
| 41 | Red background |
| 42 | Green background |
| 43 | Yellow background |
| 44 | Blue background |
| 45 | Magenta background |
| 46 | Cyan background |
| 47 | White background |
| 49 | Default background color |
As you could see from the table, you are able to set foreground and background colors separately, also you could combine them into one sequence (for example, ESC[1;33;44m – bright yellow text on blue background).
Attention: Don’t forget to turn off all attributes before exit, otherwise all following text would be displayed with your attributes.
That’s enough of the theory, let’s examine example:
1 2 3 4 | # Actual work puts "Importing categories [ e[32mDONEe[0m ]" # Actual work puts "Importing tags [e[31mFAILEDe[0m]" |
As the result you will see something like following:
All my life I used codes just like shown in the previous example, but not so long ago I found simple helpers when delving in the RSpec sources:
1 2 3 4 5 6 7 8 9 10 11 | def colorize(text, color_code) "#{color_code}#{text}e[0m" end def red(text); colorize(text, "e[31m"); end def green(text); colorize(text, "e[32m"); end # Actual work puts 'Importing categories [ ' + green('DONE') + ' ]' # Actual work puts 'Importing tags [' + red('FAILED') + ']' |
It’s a good idea, and now I’m using it. And recommend it to you :-)
Now about sorrowful things. Windows XP (and as far as I remember, Windows 2000 too) does not support ANSI escape sequences. If you are love perversions, look at the Command Interpreter Ansi Support article. Others could stay here and look, how to solve problem using Ruby facilities.
You should install win32console first:
1 | gem install win32console |
Now add following lines at the beginning of your script (and again, I found them in RSpec):
1 2 3 4 5 | begin require 'Win32/Console/ANSI' if RUBY_PLATFORM =~ /win32/ rescue LoadError raise 'You must gem install win32console to use color on Windows' end |
Script output will be colorized both on windows and Unix systems.
And in the end I will show full table of different codes, which you could use in your scripts:
It has been obtained using following script:
1 2 3 4 5 6 7 8 9 10 11 12 | #!/usr/bin/ruby [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 |
Updated 06/10/2010: Replaced PLATFORM constant with the RUBY_PLATFORM (thanks to Ian Alexander Wood).
Большое спасибо за статью!
Непременно воспользуюсь всем выше перечисленным..
Классная штука – я это для тестов приспособил.
Thanks for the code, it helped a lot for a console app that I am working on.
This is a great article. If you continue to write interesting things like this I will have to subscribe to your feed!
спасибо за статью. я как–бы думал, што у руби может быть свой стиль колоризации, но оказывается это те же саммые анси .)
Круто, спасибо!
Прикрутил это у себя и к серверной консоли, и к autotest..
Правда, не без помощи такой-то матери – простое добавление в environment.rb для autotest не достаточно, пришлось продублировать в .autotest
I have similar problem but I wanted to see Rails log colors in win console.
A little addition.
1. create file console.rb
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require 'win32console'
include Win32::Console::ANSI
include Term::ANSIColor
puts bold
[…] Colorizing console Ruby-script output | Dmytro Shteflyuk’s Home Colorizing console Ruby-script output (tags: Ruby ansi console code) […]
Я так делаю обычно:
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def red; colorize(self, "\e[1m\e[31m"); end
def green; colorize(self, "\e[1m\e[32m"); end
def dark_green; colorize(self, "\e[32m"); end
def yellow; colorize(self, "\e[1m\e[33m"); end
def blue; colorize(self, "\e[1m\e[34m"); end
def dark_blue; colorize(self, "\e[34m"); end
def pur; colorize(self, "\e[1m\e[35m"); end
def colorize(text, color_code) "#{color_code}#{text}\e[0m" end
end
И при использовании
[…] Windows. Procurei na internet e encontrei um post no LedNerd (que é tradução de um super-post do kpumuk). No Windows, a coloração do console é possível graças a gem […]