converts directory of java files into an eclipse project

eclipsifier.rb

#! /usr/bin/ruby

# by charles bailey (@c650)
# under MIT License
# 9.20.16

require 'fileutils'

if ARGV.length != 4
	puts "Usage: ./program [code dir] [new project dir] [example dir] [project name]"
	exit(1)
end

puts "Starting to make Eclipse folder..."

code_dir = File.expand_path(ARGV[0])
new_project_dir = File.expand_path(ARGV[1])
example_dir = File.expand_path(ARGV[2])

# Start initializing directories...
FileUtils.mkdir_p(new_project_dir)

src_dir = new_project_dir+"/src"
FileUtils.mkdir_p(src_dir)

bin_dir = new_project_dir+"/bin"
FileUtils.mkdir_p(bin_dir)

# copy stuff into new directory
puts "Copying All Java Files to #{new_project_dir}/src..."

Dir.chdir(code_dir)
FileUtils.cp_r(Dir.glob("*.java"), src_dir)

puts "Copying Hidden Configuration Files..."

Dir.chdir(example_dir)
FileUtils.cp_r(["./.classpath", "./.settings", "./.project"], new_project_dir)

Dir.chdir(new_project_dir)
project_file = new_project_dir+"/.project"

puts "Naming project to #{ARGV[3]}"
f = File.read(project_file).gsub("PROJECT_NAME", ARGV[3])
File.open(project_file, "w") do |file|
	file.puts f
end