# Using gems in a script or irb

**URL:** <https://www.ruby-forum.com/t/using-gems-in-a-script-or-irb/131770>\
**Category:** Ruby\
**Created:** [March 13, 2008, 3:46am UTC](https://www.ruby-forum.com/t/using-gems-in-a-script-or-irb/131770 "2008-03-13T03:46:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dsoftware](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/82dd89/32.png) [@dsoftware](https://www.ruby-forum.com/u/dsoftware)\
**Post date:** [March 13, 2008, 3:46am UTC](https://www.ruby-forum.com/t/using-gems-in-a-script-or-irb/131770/1 "2008-03-13T03:46:04Z")

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Hello,

I am in the process of trying to setup a ruby development environment  
(not  
for Ruby on Rails), and I was wondering how I go about using ruby gems  
in a  
script or from irb. I have tried setting the environment variables in  
the  
two following ways:

$ printenv | grep GEM  
GEM\_HOME=/usr/lib/ruby/gems/1.8/gems/  
GEM\_PATH=/usr/lib/ruby/gems/1.8/gems/  
$ ls $GEM\_PATH  
hoe-1.5.0 hoe-1.5.1 ParseTree-2.1.1 rake-0.8.1 ruby2ruby-1.1.8  
rubyforge-0.4.4 rubyforge-0.4.5 rubygems-update-1.0.1  
RubyInline-3.6.6  
$ irb  
irb(main):001:0\> require “ruby2ruby”  
LoadError: no such file to load – ruby2ruby  
from (irb):1:in `require’  
from (irb):1  
irb(main):002:0\>

== and ==  
$ printenv | grep GEM  
GEM\_HOME=/usr/lib/ruby/gems/1.8/  
GEM\_PATH=/usr/lib/ruby/gems/1.8/  
$ ls $GEM\_PATH  
cache doc gems source\_cache specifications  
$ irb  
irb(main):001:0\> require ‘ruby2ruby’  
LoadError: no such file to load – ruby2ruby  
from (irb):1:in `require’  
from (irb):1  
irb(main):002:0\>

Every time I google a majority of the links point to some documentation  
on  
how to set-up and configure Ruby on Rails. I am just trying to set-up  
an  
environment, where I can write a script and use gems directly in the  
script  
or from the irb prompt. For example:

#foobar.rb  
require ‘foo’ # where foo is a module in my gems directory  
foo.new(‘bar’)

$ruby foobar.rb

Thanks in advance for your help.

---

<div class="post-metadata">

**Author:** ![dsoftware](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/82dd89/32.png) [@dsoftware](https://www.ruby-forum.com/u/dsoftware)\
**Post date:** [March 13, 2008, 3:54am UTC](https://www.ruby-forum.com/t/using-gems-in-a-script-or-irb/131770/2 "2008-03-13T03:54:16Z")

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Demonic S. wrote:

> I am in the process of trying to setup a ruby development environment (not  
> for Ruby on Rails), and I was wondering how I go about using ruby gems in a  
> script or from irb.

This works:

$ echo $RUBYOPT  
rubygems

That causes ruby to run as if you specified -rubygems on the command  
line, and there is a lib called ubygems.rb (without the “r”) that this  
loads and which then sets up gems.

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<div class="post-metadata">

**Author:** ![dsoftware](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/82dd89/32.png) [@dsoftware](https://www.ruby-forum.com/u/dsoftware)\
**Post date:** [March 13, 2008, 4:08am UTC](https://www.ruby-forum.com/t/using-gems-in-a-script-or-irb/131770/3 "2008-03-13T04:08:56Z")

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Thanks Joel.

On Wed, Mar 12, 2008 at 9:53 PM, Joel VanderWerf  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)