In this tutorial we will learn about,How to easily install ruby 2.1.0 in CentOS and RHEL.Ruby is a dynamic,open source programming language.At the time of writing this post,ruby version 2.1.0 is available.For installing the ruby version in CentOS and RHEL linux system,we will use RVM method.

What is RVM

RVM stands for Ruby Version Manager.RVM is a command-line tool which allows you to easily install, manage, and work with multiple ruby environments from interpreters to sets of gems. (Reference: http://rvm.io/)

To install ruby in Linux system,follow the given below steps

Step 1: Install the latest stable RVM.It is a script which helps you to install required packages.
Note: There is a regular progress in RVM script.The RVM script may undergo with some changes.

curl -L get.rvm.io | bash -s stable

Step 2: Setup the RVM environment. With the above first step 1,we will get the rvm.sh script which helps to setup the RVM environment. This will be mentioned in output from first command which we have done in Step 1.
At the time of writing,the rvm.sh is located in /etc/profile.d/rvm.sh

source /etc/profile.d/rvm.sh

Now check where rvm command is installed.Use which command.
Below given command is reference

[root@localhost ~]# which rvm
/usr/local/rvm/bin/rvm
[root@localhost ~]# 

Step 3: Install the requirements or dependency.The rvm command also help you to install requirements automatically.Just run the below given command

rvm requirements

Below given is reference from our system.You can see the dependency packages which are installed automatically.

[root@localhost ~]# rvm requirements
Checking requirements for centos.
Installing requirements for centos.
Updating system.
Installing required packages: patch, gcc-c++, patch, readline-devel, zlib-devel, libyaml-devel, libffi-devel, openssl-devel, autoconf, automake, libtool, bison............................
Requirements installation successful.
[root@localhost ~]#

Step 4: Now install ruby version 2.1.0 .Likewise you can also install other version.As per post,we are installing ruby 2.1.0 only

rvm install 2.1.0

Below given is the reference from our system.

[root@localhost ~]# rvm install 2.1.0
Searching for binary rubies, this might take some time.
No binary rubies available for: centos/6/x86_64/ruby-2.1.0.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for centos.
Requirements installation successful.
Installing Ruby from source to: /usr/local/rvm/rubies/ruby-2.1.0, this may take a while depending on your cpu(s)...
ruby-2.1.0 - #downloading ruby-2.1.0, this may take a while depending on your connection...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 11.4M  100 11.4M    0     0   376k      0  0:00:31  0:00:31 --:--:--  459k
ruby-2.1.0 - #extracting ruby-2.1.0 to /usr/local/rvm/src/ruby-2.1.0.
ruby-2.1.0 - #applying patch /usr/local/rvm/patches/ruby/2.1.0/changeset_r44327.diff.
ruby-2.1.0 - #applying patch /usr/local/rvm/patches/ruby/2.1.0/GH-488.patch.
ruby-2.1.0 - #configuring....................................................
ruby-2.1.0 - #post-configuration.
ruby-2.1.0 - #compiling..................................................................................
ruby-2.1.0 - #installing................................
ruby-2.1.0 - #making binaries executable.
ruby-2.1.0 - #downloading rubygems-2.2.1
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  401k  100  401k    0     0  74137      0  0:00:05  0:00:05 --:--:-- 1084k
No checksum for downloaded archive, recording checksum in user configuration.
ruby-2.1.0 - #extracting rubygems-2.2.1.
ruby-2.1.0 - #removing old rubygems.
ruby-2.1.0 - #installing rubygems-2.2.1............
ruby-2.1.0 - #gemset created /usr/local/rvm/gems/ruby-2.1.0@global
ruby-2.1.0 - #importing gemset /usr/local/rvm/gemsets/global.gems.....
ruby-2.1.0 - #generating global wrappers.
ruby-2.1.0 - #gemset created /usr/local/rvm/gems/ruby-2.1.0
ruby-2.1.0 - #importing gemsetfile /usr/local/rvm/gemsets/default.gems evaluated to empty gem list
ruby-2.1.0 - #generating default wrappers.
ruby-2.1.0 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
Install of ruby-2.1.0 - #complete 
Ruby was built without documentation, to build it run: rvm docs generate-ri
[root@localhost ~]# 

Step 5: Make the newly installed ruby version 2.1.0 as a default ruby to be used in system.

rvm use 2.1.0 --default

Below is the refrence from our system,As per output,we can see which path of ruby version 2.1.0,it is using(i.e /usr/local/rvm/gems/ruby-2.1.0 )

[root@localhost ~]#  rvm use 2.1.0 --default
Using /usr/local/rvm/gems/ruby-2.1.0
[root@localhost ~]# 

Step 6: Now check the ruby version which is installed.By using command –

ruby -v

See the output given below

[root@localhost ~]# ruby -v
ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-linux]
[root@localhost ~]#