Introducción

Breve Introducción a RubyGems

Contents

• 1 Aim
• 2 Searching
• 3 Installing
• 4 Outdated
• 5 Updating
• 6 Clean
• 7 Removing
• 8 Listing installed gems

Aim

To give an overview of installing gems, updating them and, if necessary, removing them. We'll also look at some housekeeping and clean up and remove older versions of updated gems.

Searching

Installing a gem in fair enough but what if you don't know what it's called?

Well, one way of finding a gem is to look at the rubygems homepage at http://rubyforge.org/projects/rubygems/

However, this can be a bit overwhelming and may be a long way around if you know what you are looking for. In cases like these you can search a remote list of gems for the phrase you are after:

 gem search mysql --remote gems.rubyforge.org

This will give a list of gems with the word 'mysql' in them.

Si queremos ver todas las versiones de una gema usamos al opción -a:

 
[~/local/src/ruby/sinatra/rack/hangout-framework(master)]$ gem list 'erubis$' -a -r

*** REMOTE GEMS ***

erubis (2.7.0, 2.6.6, 2.6.5, 2.6.4, 2.6.3, 2.6.2, 2.6.1, 2.6.0, 2.5.0, 2.4.1, 
        2.4.0, 2.3.1, 2.3.0, 2.2.0, 2.1.0, 2.0.1, 2.0.0, 1.1.0, 1.0.1, 1.0.0)

Installing

Installing a particular gem is very simple:

 gem install mysql

That will, not unsurprisingly, install the gem 'mysql' (which is the ruby bindings for MySQL, not MySQL itself!).

The example above will give a choice of versions to install. On a Linux VPS simply choose the latest 'ruby' version. So at the time of writing I would select option (3) mysql 2.7 (ruby).

Often a gem will have several dependencies with it. To stop the install asking if you want the dependencies to be installed use this:

 gem install mysql --include-dependencies

Outdated

To get a list of gems that are now outdated (they have a newer version available), use this command:

 gem outdated

Updating

To update all the installed rubygems is just as straightforward:

 gem update

However, you may not want to update all at once, in which case specify the gem:

 gem update mysql

Clean

This will remove outdated versions of gems that are installed, leaving the new updated version installed:

 gem clean

This will leave a nice and shiny up to date rubygems install.

Removing

At some point you may want to get rid of a gem completely. No problem:

 gem uninstall mysql

Listing installed gems

To get a list of locally installed gems, issue this command:

 gem list

That will give an overview of the gems you have installed.

Instalando una gema en local

You can use gem install --local path_to_gem/filename.gem

This will skip the usual gem repository scan that happens when you leave off --local.

Toda la información sobre una gema:gem spec

[~/Dropbox/src/ruby/sinatra/bootstrap_example(master)]$ gem spec sinatra
--- !ruby/object:Gem::Specification
name: sinatra
version: !ruby/object:Gem::Version
  version: 1.4.2
platform: ruby
authors:
- Blake Mizerany
- Ryan Tomayko
- Simon Rozet
- Konstantin Haase
autorequire: 
bindir: bin
cert_chain: []
date: 2013-03-21 00:00:00.000000000 Z
dependencies:
- !ruby/object:Gem::Dependency
  name: rack
  requirement: !ruby/object:Gem::Requirement
    requirements:
    - - '>='
      - !ruby/object:Gem::Version
        version: 1.5.2
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.5'
  type: :runtime
  prerelease: false
  version_requirements: !ruby/object:Gem::Requirement
    requirements:
    - - '>='
      - !ruby/object:Gem::Version
        version: 1.5.2
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.5'
- !ruby/object:Gem::Dependency
  name: tilt
  requirement: !ruby/object:Gem::Requirement
    requirements:
    - - '>='
      - !ruby/object:Gem::Version
        version: 1.3.4
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.3'
  type: :runtime
  prerelease: false
  version_requirements: !ruby/object:Gem::Requirement
    requirements:
    - - '>='
      - !ruby/object:Gem::Version
        version: 1.3.4
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.3'
- !ruby/object:Gem::Dependency
  name: rack-protection
  requirement: !ruby/object:Gem::Requirement
    requirements:
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.4'
  type: :runtime
  prerelease: false
  version_requirements: !ruby/object:Gem::Requirement
    requirements:
    - - ~>
      - !ruby/object:Gem::Version
        version: '1.4'
description: Sinatra is a DSL for quickly creating web applications in Ruby with minimal
  effort.
email: sinatrarb@googlegroups.com
executables: []
extensions: []
extra_rdoc_files:
- README.de.md
- README.es.md
- README.fr.md
- README.hu.md
- README.jp.md
- README.ko.md
- README.md
- README.pt-br.md
- README.pt-pt.md
- README.ru.md
- README.zh.md
- LICENSE
files:
- README.de.md
- README.es.md
- README.fr.md
- README.hu.md
- README.jp.md
- README.ko.md
- README.md
- README.pt-br.md
- README.pt-pt.md
- README.ru.md
- README.zh.md
- LICENSE
homepage: http://www.sinatrarb.com/
licenses: []
metadata: {}
post_install_message: 
rdoc_options:
- --line-numbers
- --inline-source
- --title
- Sinatra
- --main
- README.rdoc
- --encoding=UTF-8
require_paths:
- lib
required_ruby_version: !ruby/object:Gem::Requirement
  requirements:
  - - '>='
    - !ruby/object:Gem::Version
      version: '0'
required_rubygems_version: !ruby/object:Gem::Requirement
  requirements:
  - - '>='
    - !ruby/object:Gem::Version
      version: '0'
requirements: []
rubyforge_project: 
rubygems_version: 2.0.3
signing_key: 
specification_version: 3
summary: Classy web-development dressed in a DSL
test_files: []

Véase También

• Ruby for Newbies: Working with Gems
• Artículo de Linux Journal sobre RubyGems
• RubyGems.org home page
• docs.rubygems.org home page
• help.rubygems.org home page
• Véase RubyGems User Guide.

Seguridad

1. module Gem::Security