Rakefile to deploy dotfiles

gistfile1.rb

require 'rake'
require 'digest'
begin
    require 'grit'
rescue
end

$home = ENV['HOME']
raise "#{$home} is not a directory" if not File.directory? $home

task :default => :install_all

desc "Copy dotfiles into home directory w/correct permissions."
task :install_all do
    begin
        repo = Grit::Repo.new('.')
        branch = repo.head.name
    rescue
    end
    puts "Installing dotfiles #{branch.nil? ? "" : "from " + branch + " "}into #{$home} ..."
    files = %w{
        bash_profile
        bashrc
        gemrc
        gitconfig
        gitignore
        gvimrc
        inputrc
        lbdbrc
        logrotate
        screenrc
        ssh
        vim
        vimrc
    }
    files.each { |f| install f }
end

def install(filename)
    if File.directory?(filename)
        dest_filename = dest(filename)
        if not File.directory? dest_filename
            mkdir_p dest_filename, :verbose => false
        end
        dir_mode = File.lstat(dest_filename).mode
        if dir_mode != 0755
            chmod 0755, dest_filename, :verbose => false
        end
        Dir[File.join(filename, '*')].each {|f| install f }
    else
        dest_filename = dest(filename)
        if File.exists? dest_filename 
            if same_version? filename
                return
            end
            if not File.writable? dest_filename
                # Temporarily make it writable
                file_mode = File.lstat(dest_filename).mode
                chmod file_mode | 0200, dest_filename, :verbose => false
            end
        end
        copy_f filename
    end
end

def dest(filename)
    File.join($home, '.' + filename)
end

def same_version?(filename)
    sha = Digest::SHA1.new
    file_sha = sha.file(filename)
    sha = Digest::SHA1.new
    dest_file_sha = sha.file(dest(filename))
    file_sha == dest_file_sha ? true : false
end

def copy_f(filename)
    dest_filename = dest(filename)
    puts "Copying #{filename} to #{dest_filename} ..."
    cp filename, dest_filename, :verbose => false
    chmod 0444, dest_filename, :verbose => false
end