Thank you for reading this question.
$ gem install yt
Successfully installed yt-0.32.4
1 gem installed
$ gem which yt
/Users/klee/.rbenv/versions/2.5.4/lib/ruby/gems/2.5.0/gems/yt-0.32.4/lib/yt.rb
$ gem install yt-core
Successfully installed yt-core-0.1.7
1 gem installed
$ gem which yt-core
ERROR: Can't find Ruby library file or shared library yt-core
I keep trying to install this gem, but it keeps saying "Can't find." Same thing happens to you? How can I install and find this gem? This is the gem I'm trying to install https://rubygems.org/gems/yt-core
From the documentation:
GEM WHICH
Find the location of a library file you can require
So when you call gem which you need to provide an actual module you can require, not just the name of the gem. And if you look at the source for the yt gem you'll see the following structure:
lib/
yt.rb
And you'll notice that the content of yt.rb is:
module Yt
end
So when you call gem which yt it is able to find that module and tell you where to find it. (lib/yt.rb)
But if you look at the source for yt-core you'll see there is no file inside the lib/ directory, and instead all files are inside lib/yt:
lib/
yt/
...
core.rb
...
And the source for core.rb is:
module Yt
end
So if you want to find the location of the module, you need to run:
gem which yt/core
/Users/foo/.rvm/gems/ruby-2.6.3/gems/yt-core-0.1.7/lib/yt/core.rb
Or yt/channel or yt/group, etc.
So to use this gem, you would need to include this in your source:
require 'yt/core'
Related
I want to setup gem from rubygems.org to some subfolder of my project like "/gems" and then use it from script via require. Please help me resolve it.
The preferred way is to go with a standard scenario: you build a gem, with binaries, pack it and when used it will download all the dependencies itself, according to gemspec. If the above is for some reason non-acceptable for you, one of the options would be:
• You create a gem for your script;
• You specify a path where to install dependencies:
bundle install --path=vendor/gems
• Instead of require you use require_relative in your script because on destination machines there won’t be local bundle’s config file, pointing to the right folder;
• As your script is finished, you pack everything including gems.
The normal way to go in a ruby project is to setup a Gemfile and use bundler (see link for more info) to handle the gems your project requires, without having to think of where they are stored
However, if there really is no way around shipping an own gem-directory, e.g. because your productive system has absolutely no way to access the internet, you could make it this way:
Create a directory in the root of your project (e.g. 'gems').
Download and unpack the gems to that directory (or use the appropriate options of gem install to redirect the installation into that directory)
Create a ruby file in the root directory of your project with following constants:
PROJECT_DIR = __dir__
GEMS_DIR = File.join(PROJECT_DIR, 'gems')
Now you can require your gems link require File.join(GEMS_DIR, <gem_name>)
Nonetheless, you should really think about using bundler, if possible in any way.
EDIT: to install gem via gem install
Delete the PG data from your project's gems directory
uninstall global gem gem uninstall pg
Install pg again, but into your project's directory: gem install -i <path_to_projects_gems_dir> pg
Run you script again with the require pointing to the gem stated above
I solved it like this:
gem install -i ./ pg
ROOT = File.expand_path('..', __FILE__)
ENV['GEM_PATH'] = File.join(ROOT, './')
require 'pg'
puts 'Version of libpg: ' + PG.library_version.to_s
I am trying to include the ruby-mysql gem in my ruby script. I have installed the gem using bundler but when I run bundle exec ./mysql_connector, I receive the error ./mysql_connector:4:in ``require': cannot load such file -- ruby-mysql (LoadError). Can you please help me troubleshoot what the problem is?
What I did
Installed rails in my home directory.
I do not have root access to the server so I have installed rails in my local directory by following the instructions here:
http://www.r-bloggers.com/installing-ruby-on-linux-as-a-user-other-than-root/
Created a directory for my application.
My application resides in my home directory in a folder called connector. It has a Gemfile that looks like this:
source 'https://rubygems.org'
gem 'ruby-mysql'
Call bundle install.
Using ruby-mysql 2.9.14
Using bundler 1.11.2
Bundle complete! 1 Gemfile dependency, 2 gems now installed.
Bundled gems are installed into ./vendor/bundle.
Add dependencies to my script. My script is in connector/mysql_connector and it reads:
#!/home/dcox/bin/ruby
require 'rubygems'
require 'bundler/setup'
require 'ruby-mysql'
Make script executable. I saw that you need to run bundle exec using an executable file, so I followed the instructions here to make my script executable: http://commandercoriander.net/blog/2013/02/16/making-a-ruby-script-executable/
Run the script. I execute using bundle exec mysql_connector and see:
/home/dcox/bin/mysql_connector:4:in `require': cannot load such file -- ruby-mysql (LoadError)
from /home/dcox/bin/mysql_connector:4:in `<main>'
Is it the $LOAD_PATH? After searching around for answers, I discovered a lot of SO answers as well as a blog post (https://codedecoder.wordpress.com/2013/09/23/require-and-load-in-ruby-loaderror-cannot-load-such-file/) that seem to suggest the problem is that the gem is not installed in a directory on the $LOAD_PATH. Here is what I see when I run $LOAD_PATH from IRB:
irb(main):002:0> $LOAD_PATH
=> ["/home/dcox/lib/ruby/site_ruby/2.1.0",
"/home/dcox/lib/ruby/site_ruby/2.1.0/x86_64-linux",
"/home/dcox/lib/ruby/site_ruby", "/home/dcox/lib/ruby/vendor_ruby/2.1.0",
"/home/dcox/lib/ruby/vendor_ruby/2.1.0/x86_64-linux",
"/home/dcox/lib/ruby/vendor_ruby", "/home/dcox/lib/ruby/2.1.0",
"/home/dcox/lib/ruby/2.1.0/x86_64-linux"]
Next I checked to see the location of ruby-mysql:
dcox#analytics1:~/connector$ bundle show ruby-mysql
/data/home/dcox/connector/vendor/bundle/ruby/2.1.0/gems/ruby-mysql-2.9.14
Obviously my connector/vendor/bundle path is not on the $LOAD_PATH. I could add it, but I have a feeling I am missing something simple here because bundler is supposed to work as long as you follow the instructions, right?
Any advice or help is very much appreciated! Thanks!!
If you just want to require this specific gem, require 'mysql' should work (e.g., https://github.com/tmtm/ruby-mysql/blob/master/test/test_mysql.rb#L10).
Your file should call Bundler.setup http://bundler.io/bundler_setup.html
Better yet, if you instead call Bundler.require(:default) it will setup and require all the gems in your Gemfile for you.
I forked a gem I use a lot in order to code some enhancements on it. I want it to be installed in a subfolder called ~/codebase/ruby, where I keep all my Ruby projects, arranged in subdirectories.
To do that, I built and installed the gem with the following commands:
gem build my_gem.gemspec
gem install mygem-x.x.gem -i./mygem
mygem is installed in ~/codebase/ruby/mygem. I can't get my client code (which is in another directory) to grab mygem from there.
I've tried all of the following without success:
Running ruby with argument -I<path_to_mygem>.
Adding <path_to_mygem> to PATH.
Putting :gempath: <path_to_mygem> into ~/.gemrc.
I know I could put the gem in ~/.gem/ruby/<version> (since it appears in gem env) and that would probably work, but that would break my existing directory structure of Ruby code, forcing me to code in a different directory only for mygem, which is something I want to avoid unless it's the only option.
Thoughts?
Hopefully you are using Bundler to load the required gems. Then you just specify the path to the gem file in your Gemfile:
gem 'my_gem', :path => '~/codebase/ruby/mygem'
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 pack some ruby code into a gem. I want to refer the code in the gem in some other code.
So in the Gemfile I specify the gem's name, version, and local path. Like:
gem 'gemname','0.x', :path => 'RELATIVE_PATH_TO_GEM_FILE'
After bundle install, I see
Using gemname (0.x) from source at RELATIVE_PATH_TO_GEM_FILE
But when I run the code, it can't find the code in the gem. LOAD_PATH shows ABSOLUTE_PATH_TO_GEM_FILE/lib.
No wonder it can't find the code, there's only gem file under ABSOLUTE_PATH_TO_GEM_FILE. it's not unpacked. So there's no lib directory.
if I gem install that gem file into my system, then all works fine. I can see the gem file was unpacked into source code files.
But my question is if it can refer the local gem file directly somehow?
No, you can't refer to a .gem file directly.
In your terminology, you need to use an "unpacked" gem.
:path => '/foo/bar/'
where /foo/bar/ is a (gem) directory with lib/, etc.
We made a local (not system-wide) gems location. We set these environment variables:
GEM_HOME=/path/to/rubygems-1.3.4
RUBYLIB=/path/to/rubygems-1.3.4/lib/
By setting those, we can then do 'gem install ...' to put the built gem into that directory, and ruby knows where to find them.