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Ruby Paint

Paint creates terminal colors and effects for you. It combines the strengths of term-ansicolor, rainbow, and similar projects into a simple to use, however still flexible terminal colors gem with no core extensions by default.

Supported Rubies: 3.3, 3.2, 3.1, 3.0

Unsupported, but might still work: 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9

Features

  • No string extensions (suitable for library development)
  • Simple API
  • Faster than other terminal color gems (as of January 2024)
  • Supports true color or 256 colors (for capable terminals)
  • Allows you to set any terminal effects
  • Paint.mode: Fall-back modes for terminals with less colors, supported modes:
    • 0xFFFFFF (= 16777215) colors (true color)
    • 256 colors (palette)
    • 16 colors (only ANSI colors, combined with bright effect)
    • 8 colors (only ANSI colors)
    • 0 colors (no colors / deactivate)

Paint 2.0 | True Color Support

Starting with Paint 2.0, true color mode is the new default mode, since most major terminals now support 24bit colors. If it happens to not work in your setup:

  • Manually set Paint.mode = 256 at the beginning of your code
  • Please open a new issue so we can figure out how to blacklist the terminal used

Setup

Add to Gemfile:

gem 'paint'

and run bundle install.

In Ruby do:

require 'paint'

Usage

The only method you need is: Paint.[]

The first argument given to Paint.[] is the string to colorize (if the object is not a string, to_s will be called on it). The other arguments describe how to modify/colorize the string. Let's learn by example:

Paint['Ruby', :red]           # Sets ANSI color red
Paint['Ruby', :red, :bright]  # Also applies bright/bold effect
Paint['Ruby', :bright, :red]  # Does the same as above
Paint['Ruby', :red, :bright, :underline] # Effects can often be combined
Paint['Ruby', :red, :blue]    # The second color you define is for background
Paint['Ruby', nil, :blue]     # Pass a nil before a color to ignore foreground and only set background color
Paint['Ruby', [100, 255, 5]]  # You can define RGB colors. Depending on your terminal, this will create
                              # a "true color" or map to 256/16/8 colors.
Paint['Ruby', "gold", "snow"] # Paint supports rgb.txt color names, note that the arguments are strings
                              # (:yellow != "yellow")!
Paint['Ruby', "#123456"]      # HTML like definitions are possible
Paint['Ruby', "fff"]          # Another HTML hex definition
Paint['Ruby', :inverse]       # Swaps fore- and background
Paint['Ruby', :italic, :encircle, :rapid_blink, :overline] # Probably not supported effects
Paint['Ruby']                 # Don't pass any argument and the string will not be changed

When you pass multiple colors, the first one is taken as foreground color and the second one defines the background color, every following color will be ignored. To only change the background color, you have to pass a nil first. Effects can be passed in any order.

You can find more examples in the specs.

List of rgb.txt colors.

Windows Support

For ANSI support in Windows OS, you can use ansicon or ConEmu or WSL.

Paint.mode

You can choose between five ways to use Paint.[] by setting Paint.mode to one of the following:

  • 0xFFFFFF: Use 16777215 true colors
  • 256: Use the 256 colors palette
  • 16: Use the eight ANSI colors (combined with bright effect)
  • 8: Use the eight ANSI colors
  • 0: Don't colorize at all

Paint tries to automatically detect the proper value your terminal is capable of, please open an issue if Paint.detect_mode yields a wrong value for you.

Paint.detect_mode will return 0 if the NO_COLOR environment variable is set.

More Details About Terminal Colors and Effects

Terminal colors/effects get created by ANSI escape sequences. These are strings that look like this: \e[X;X;X;X;X]m where X are integers with some meaning. For example, 0 means reset, 31 means red foreground and 41 stands for red background. When you tell Paint to use one of the eight ANSI base colors as foreground color, it just inserts a number between 30 and 37 into the sequence. The following colors are available:

  • :black
  • :red
  • :green
  • :yellow
  • :blue
  • :magenta
  • :cyan
  • :white, :gray
  • (:default)

When combined with the :bright (= :bold) effect, the color in the terminal emulator often differs a little bit, thus it is possible to represent 16 colors.

Through special sequences it's also possible to set 256-colors, or even 16777215 colors, instead of only the 8 ANSI ones. However, this is not supported by all terminals. Paint automatically translates given RGB colors to a suitable color of the supported color spectrum.

When using the Paint.[] method, Paint wraps the given string between the calculated escape sequence and an reset sequence ("\e[0m"). You can get the raw escape sequence by using the Paint.color method.

Effects

See en.wikipedia.org/wiki/ANSI_escape_code for a more detailed discussion:

Often supported

0) :reset, :nothing
1) :bright, :bold
4) :underline
7) :inverse, :negative
8) :conceal, :hide
22) :clean
24) :underline_off
26) :inverse_off, :positive
27) :conceal_off, :show, :reveal

Not widely supported

2) :faint
3) :italic
5) :blink, :slow_blink
6) :rapid_blink
9) :crossed, :crossed_out
10) :default_font, :font0
11-19) :font1, :font2, :font3, :font4, :font5, :font6, :font7, :font8, :font9
20) :fraktur
21) :bright_off, :bold_off, :double_underline
23) :italic_off, :fraktur_off
25) :blink_off
29) :crossed_off, :crossed_out_off
51) :frame
52) :encircle
53) :overline
54) :frame_off, :encircle_off
55) :overline_off

Substitution & Nesting

From time to time, you might find yourself in a situation where you want to colorize a substring differently from the rest of the string. Paint supports this via a simple templating approach using the % method with an array argument. Use the %{var} notation within a string, and pass the template variables as a hash:

Paint%['Yellow string with a %{blue_text} in it', :yellow,
  blue_text: ["blue text", :blue]
]
# => "\e[33mYellow string with a \e[34mblue text\e[0m\e[33m in it\e[0m"

Please note that the resulting ASCII escape sequence can be quite verbose since it restores the parent context after the substitution.

Utilities

The Paint.random method generates a random ANSI color you can pass into Paint.[]:

Paint['Ruby', Paint.random]        # Get one of eight random ANSI foreground colors
Paint['Ruby', Paint.random(true)]  # Get one of eight random ANSI background colors

Another helper method is Paint.unpaint, which removes any ANSI colors:

Paint.unpaint( Paint['Ruby', :red, :bright] ).should == 'Ruby'

You can get a p like alternative for calling puts Paint.[]:

require 'paint/pa'
pa "Ruby", :red, :underline  # same as puts Paint["Ruby", :red, :underline]

Advanced Usage: Shortcuts

There is an extension gem available which allows you to define custom color definitions, which you can reuse later. See SHORTCUTS.md for documentation. This is completely optional.

J-_-L

Copyright (c) 2011-2024 Jan Lelis https://janlelis.com, released under the MIT license.

Thank you to rainbow and term-ansicolor for ideas and inspiration. Also, a lot of thanks to all the contributors!