Backup one file

I found my self often doing something like that:

sudo cp /boot/grub/menu.lst /boot/grub/menu.lst_bu_2007-05-12_13-20

With the following script all we need to do is:

sudo backup-one-file /boot/grub/menu.lst

And the result is a backup created in /boot/grub/menu.lst_bu_2007-05-12_13-21-30

#!/usr/bin/env ruby

require 'fileutils'

if ARGV.empty?
        puts "Usage: backup-one-file <file-name>"
        exit
end

source = ARGV[0]

unless File.exist?(source)
        puts "Error: File #{source} does not exist!"
        exit
end

target = source + "_bu_" + Time.now.strftime("%Y-%m-%d_%H-%M-%S")

begin
        FileUtils.cp(source, target)
rescue Exception => e
        puts "Could not copy to #{target}"
        puts e.message
        puts "Maybe you need to run as root!"
else
        puts "Backup created in: #{target}"
end