更改Ruby on Rails的版本

Question

I'm trying to install a CMS that requires Ruby on Rails 3.2.x, which I presume means any version of Ruby on Rails that supersedes 3.2.0.

So I installed Rails version 3.2.8, but I can't use it.

Could someone explain what's going on here? Also, if a project requires 3.2.x does that mean I include it in the project's gemfile, or do I have to install it as I'm trying to do here?

Answer 1

To specify the version of rails you want to use, in your gemfile:

gem 'rails', 'version'

Change version to the version you want then run $ bundle install

Answer 2

RVM is the Ruby Version Manager, not rails. If that is the only version of rails you downloaded, you can start using it. If you wanted to use a specific version of ruby, you would use that command.

To use a specific version of rails, use rails _3.2.0_ app_name .

Answer 3

Use

gem list | grep rails gem list | grep rails to check your rails versions installed.

rvm use 1.xx is to switch b/w ruby versions not rails versions

Answer 4

rvm is for managing ruby interpreters. With any modern rails app, just run

bundle install

In the apps directory for all the required gems to be installed (including rails). You'll need to install the bundler gem ahead of time but that's all

Answer 5

RVM manages different ruby enviroment with different gemsets . If you want to use different rails version with same ruby you can create different gemset to avoid conflicts.

Assume you have two different ruby versions 1.9.3 and 2.0.0 (which are installed using rvm ). By default it will have default gemset got created and uses that.

rvm list

gives:

=* ruby-1.9.3-p0 [ i686 ]
ruby-2.0.0-p0 [ i686 ]

# => - current
# =* - current && default
#  * - default

Assume you have rails 3.0.0 installed in default environment. And now you want to have one more rails version with different gemset you can create as follows:

  rvm gemset create rails-3.2.8
  rvm use 1.9.3-p0@rails-3.2.8  # Switching enviroment

This will create different environment with ruby 1.9.3 and rails 3.2.8.