I'm trying to write a program with colorized output. I looked at a few, and the gem I found was colorize. I've done some research, but I can't find step-by-step instructions on how to install a gem, require it, and use it. The gem I want is colorize, and I also need to know if there's anything else it requires. All I have is the standard ruby console that comes in the Ruby21 file, and notepad++ to write and save it. I need to know how and where to install it, whether I type something into the terminal or download a file and put it somewhere, and how to require it and its prerequisites(if any) in a file.
You can install the gem using your CLI simply by typing: gem install colorize. You can then utilize the gem by requiring it, so at the top of your .rb file add require 'colorize'. Then just test it out by trying puts "This is blue".colorize(:blue).
Your .rb could look like this for example:
require 'colorize'
puts "This is blue".colorize(:blue)
Per http://guides.rubygems.org/rubygems-basics/, you can install the colorize gem with the following command (in terminal or at command prompt):
gem install colorize
To list local gems, run this command:
gem list
And--by adding require 'colorize' to the top of the respective .rb file--that gem's lib directory will be added to your $LOAD_PATH.
Related
I just wondering can we turn a command line tool that written in ruby to a gem file ? if yes how we can run that gem ?
think I have a ruby file which print a text very simple app
now I want to package it to a gem file
then I need to run that gem
Is this doable or not ?
This is perfectly possible. RubyGem has a guide on this. Basically you'll need to:
Apart the gem structure, you'll want to see how to add an executable to it by creating a file in the bin folder with something like:
#!/usr/bin/env ruby
require 'yourmainfile'
# call your code here
I'm writing a batch script as a setup for a ruby program I'm writing. It needs to be able to
a. Make sure Ruby is installed on the user's computer (and if not point them to the ruby download page)
b. make sure the ruby "yaml" gem is installed, which is a prerequisite for it. I've tried
gem install yaml
in the batch script to no avail. How can I write a batch script that will do these two things?
As far as I know, there is no yaml gem. Although it must be required in code that uses it, it is distributed as part of a Ruby installation. Try this:
ruby -ryaml -e"puts 'YAML found'"
It should work; and if you change the -r token to some nonexistent gem, you'll see an exception raised.
Instead of writing your own script, you could use bundler and create a gemfile. This way people can install all the gems on any operating system.
Example:
require 'rubygems'
require 'bundler/setup'
require 'nokogiri'
require 'rest-client'
#require all your gems like normal
def parse(site)
Nokogiri::HTML(RestClient.get(site))
end
And for the gem file:
source: "https://rubygems.org"
gem 'nokogiri', '~> 1.6.7.2' #<= you can specify which version
gem 'rest-client' #<= you don't have to specify a version though
After you've got everything set up, cd to the directory that has the gemfile and run bundle install this will install all the gems
Ruby dabbler/newbie here who's not familiar with the ecosystem, so apologies if this is one of those super duh questions.
Is there a way to view all the files and/or source code installed by a gem? That is, I just ran
$ gem install sass
And the sass gem is now a part of my local system
$ gem list --local
...
sass (3.1.16, 3.1.2)
...
I want to know what the gem install command put on my system. Is there a command I can run to see all the files installed by the gem?
After some googling, man gem and gem help commands, I discovered the contents command.
$ gem contents sass
However, when I run this command with the aforementioned sass gem, I get the following results
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/engine_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/functions_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/extend_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/logger_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/css2sass_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/script_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util/subset_map_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util/multibyte_string_scanner_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/callbacks_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/importer_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/css_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/scss_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/rx_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/script_conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/less_conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/cache_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/plugin_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/sass
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/sass-convert
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/scss
However, this list seems incomplete as I know there are files in
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.2/lib/
Why does contents not show the files from lib?
Is it possible for a gem installer to install files outside of the gems folder?
Is there a command that can show everything installed by a gem?
gem has an unpack command: http://guides.rubygems.org/command-reference/#gem-unpack
gem unpack rake
ls rake-0.4.3/
There are two really good ways to do this. There is another gem which allows you to open the gem and edit. This gem is call gem-open
gem install gem-open
then
gem open sass
Another way is to generate your own rdocs.
gem rdoc sass
You can then look at your rdocs by
gem server
Also if you are using rvm, you can type rvm info and it will show GEM_HOME location.
This will be where all your gems source code is.
cd $GEM_HOME
cd gems/sass-3.1.2/
Update:
This is the way I mostly do this now, when using bundler.
cd $(bundle show sass)
This will be the version of sass in your Gemfile.
I usually open a gem by running this command from the console
EDITOR=<your editor> bundle open <name of gem>
The lib/ directory you mentioned is for version 3.1.2 of the gem; gem contents without --version will just list one version (it appears to pick the newest version, but I'm unable to verify this is always true). What output do you get for gem contents --version 3.1.2 sass?
You can also use just rename the .gem file to .tar and extract as a posix archive. The source code is inside it in the lib folder. See https://blog.srcclr.com/extracting-ruby-source-code-from-gem-packages/ for more details.
In addition to gem contents, another command you might find useful is gem environment. If you have multiple paths for your gem installations, they will all be listed under the "GEM PATHS" label.
I'm new to Ruby. I have a .bundle file. I put it in the source folder and did
require('my.bundle')
But when I call the methods in the bundle, the definition is not found. Do I have to install them or include them in some other way to access them?
I am on Ruby version 1.8.7 (latest version on Mac).
I highly recommend using RVM to manage your Ruby installation, including your gems, so if you don't already have that, get it and follow the instructions for installing it. Make sure you do the part about modifying your bash startup script or you'll see weird behavior, like the wrong Ruby being called. Also, use the steps in "RVM and RubyGems" to install your gems or you can run into weird behavior with gems being installed under the wrong or an unexpected Ruby.
Second, use the gem command to install gems:
gem install gem_to_install
replacing "gem_to_install" with the name of the gem you want, and it will be installed into the appropriate gem folder for your Ruby.
If you are on Ruby 1.92, and trying to require a gem to use as a module in your code, use:
require 'gemname'
if it is installed via the gem command. And, if it is a module you wrote or have in your program's directory or below it, use:
require_relative 'path/to/gem/gemname'
If you are on a Ruby < 1.9 you'll also need to add require 'rubygems' above your other require lines, then use require './path/to/gem/gemname'.
Thanks, but my .bundle is not in gems. How do I install/require a .bundle file I already have?
If you wrote it look into rubygems/gemcutter or bundler for info on bundling and managing gems.
You can install a gem without using the app by going into the directory containing the gem and running setup.rb. See http://i.loveruby.net/en/projects/setup/doc/usage.html for a decent writeup or the official docs at: http://docs.rubygems.org/read/chapter/3
Is there an easy way, when running a Ruby script, to get it to automatically install gems required for script?
For example, consider these require statements at the top of a ruby script:
require 'net/http'
require 'fileutils'
require 'archive/zip'
Now, I know (as a human and programmer) that for this script to run on a given PC with Ruby, the 'gem install archive-zip' command needs to be run first, before the script will work. But if this script needs to run on dozens of PCs, is there anything that can save me from having to ensure ALL the gem dependancies are installed first?
Furthermore, what if there are several gems required?
Not sure if this is exactly what you are after but when I have a server set up how I want I dump a list of my gems to somewhere safe...
gem list > my_gems.txt
If I need to rebuild the box or build another machine I use this script to install the gems...
bulk_gems.rb
#! /usr/local/bin/ruby
STDIN.readlines.each do |l|
m = l.match /^(\S+) \((.*)\)/
unless m.nil?
gem_name, versions = m[1], m[2].split(',')
versions.each do |v|
system "gem install #{gem_name} --version #{v} --ignore-dependencies"
end
end
end
more my_gems.txt | bulk_gems.rb
By using gem unpack you can unpack the gems into a directory. From there, you can include them in your script. For example, randomly picking the gem morse (a gem that encodes/decodes morse code), let's say I use gem unpack morse to put it in a directory /gems/. It unpacks to the directory morse-0.0.2, since that's the version.
$LOAD_PATH << './gems/morse-0.0.2/lib'
require 'morse'
# The gem is included, and Morse is now defined.
Shoes has a really slick way of doing this. See this blog post by _why.
You could port some of that to standard ruby (without the fancy UI)