Ruby: Cannot load such file from - LoadError
<p>I have a ruby script file with the name test.rb.</p>

<p>the file has the following two require statements:</p>

<pre><code>require 'oauth'
require 'HTTParty'
</code></pre>

<p>I have the two gems already installed before.</p>

<p>when running <strong>ruby test.rb</strong> in the terminal I get the following error:</p>

<blockquote>
  <p>/opt/rubies/ruby-2.0.0-p598/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
  <code>require': cannot load such file -- HTTParty (LoadError)
          from /opt/rubies/ruby-2.0.0-p598/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
  </code>require'
          from test.rb:2:in `'</p>
</blockquote>

<p>what can be wrong here?</p>