show erb example from docs with files

data.txt

From:  James Edward Gray II <james@grayproductions.net>
To:  <%= to %>
Subject:  Addressing Needs

<%= to[/\w+/] %>:

Just wanted to send a quick note assuring that your needs are being
addressed.

I want you to know that my team will keep working on the issues,
especially:

<%# ignore numerous minor requests -- focus on priorities %>
% priorities.each do |priority|
  * <%= priority %>
% end

Thanks for your patience.

James Edward Gray II

erb-example.rb

# based on the docs at http://ruby-doc.org/stdlib/libdoc/erb/rdoc/classes/ERB.html
require "erb"

# Create template.
template = File.read 'data.txt'
message  = ERB.new template , 0 , "%<>"

# Set up template data.
to = "Community Spokesman <spokesman@ruby_community.org>"
priorities = [ "Run Ruby Quiz",
               "Document Modules",
               "Answer Questions on Ruby Talk" ]

# Produce result.
email = message.result
puts email

output

From:  James Edward Gray II <james@grayproductions.net>
To:  Community Spokesman <spokesman@ruby_community.org>
Subject:  Addressing Needs

Community:

Just wanted to send a quick note assuring that your needs are being
addressed.

I want you to know that my team will keep working on the issues,
especially:

  * Run Ruby Quiz
  * Document Modules
  * Answer Questions on Ruby Talk

Thanks for your patience.

James Edward Gray II