piotrmurach / tty-color

Terminal color capabilities detection

TTY::Color

Terminal color capabilities detection.

TTY::Color provides independent color support detection component for TTY toolkit.

Installation

Add this line to your application's Gemfile:

gem "tty-color"

And then execute:

$ bundle

Or install it yourself as:

$ gem install tty-color

Usage

TTY::Color allows you to check if terminal supports color:

TTY::Color.color?    # => true
TTY::Color.support?  # => true

You can also get the number of colors supported by the terminal using mode method:

TTY::Color.mode # => 64

To detect if color support has been disabled with NO_COLOR environment variable, use disabled?:

TTY::Color.disabled? # => false

TTY::Color is just a module hence you can include it into your scripts directly:

#!/usr/bin/env ruby

include TTY::Color

puts color?

Command line tool

tty-color-cli is a command line tool for the TTY::Color.

To check if terminal supports colors use -s|--support:

tty-color -s
tty-color --support
# => true

And to check color mode use -m|--mode option:

tty-color -m
tty-color --mode
# => 256

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/piotrmurach/tty-color. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

1. Fork it ( https://github.com/piotrmurach/tty-color/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Code of Conduct

Everyone interacting in the TTY::Color project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

Copyright

Copyright (c) 2016 Piotr Murach. See LICENSE for further details.

tty-color's Issues

Support windows terminals

My less advanced supported color detection contains some checks for popular windows terminals. It might be useful to add this here, too.

However, right now I don't have a Windows at hand for testing.

Do not check for tty in `supports?` method

Describe the problem

I ran into issue where I test for colorized output on my CI. If I ran test from terminal then all runs well, but on my CI tests are failed. So after search for issue I found code which produces this behavior:

      # Detect if terminal supports color
      #
      # @return [Boolean]
      #   true when terminal supports color, false otherwise
      #
      # @api public
      def supports?
        return false unless TTY::Color.tty?

        value = false
        SOURCES.each do |from_check|
          break if (value = public_send(from_check)) != NoValue
        end
        return false if value == NoValue
        value
      end

After I changed the code from Pastel.new(enabled: TTY::Color.support?) to Pastel.new(enabled: true), then tests passed. I think (for UNIX systems) return false unless TTY::Color.tty? is not necessary here, check for env should do the job.

Describe your environment

• OS version: Mac OS X 10.14.2 18C54
• Ruby version: ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17]
• TTY::Color version: 0.4.3

Remove CLI?

Hello Peter,

good idea to separate color detection into its own micro gem, thank you!

What I thought after reading the readme: Is the CLI part really necessary? Couldn't it be extracted into even another gem?

This would allow people to use the gem for its purpose without having new executables in their path they maybe don't want to have.