Wanted an easy way to take a directory, copy it, and then fill in all the files within it with custom values.

fillin.rb

#!/usr/bin/env ruby

require 'optparse'
require 'securerandom'
require 'fileutils'
require 'erb'

params = {}
target_directory = "New"
# Parse args

opt_parser = OptionParser.new do |opt|
    opt.banner = "Usage: fillin [OPTIONS] DIRECTORY"
    opt.separator ""
    opt.separator "Will copy the supplied DIRECTORY and fill in all text files with options passed in."
    opt.on("-dMANDATORY", "Define parameter") do |param|
        (key,value) = param.split("=")
        params[key.to_s] = value
    end

    opt.on(:REQUIRED, "-tMANDATORY", "--target MANDATORY", "Name of new directory") do |target|
        target_directory = target
    end

    opt.on("-h","--help","help") do
       puts opt_parser
    end
end

opt_parser.parse!

directory = ARGV[0]

puts directory

# Make copy of directory with new name
FileUtils.cp_r(directory, target_directory)

# Open target and process files
Dir.foreach(target_directory) do |filename|
    filename = target_directory + "/" + filename
    puts filename
    if( File.file?(filename) )
        puts "It's a file, going to parse it"
        contents = ''
        File.open(filename, "r") do |file|
            template = ERB.new(file.read)
            contents = template.result( binding )
        end
        File.open(filename, "w") do |file|
            file.write(contents)
        end
    end
end