GoPro timelapse renamer

gollapser.rb

#!/usr/bin/env ruby

directory = ARGV[0]

ARGV.clear

puts "This will rename all *.JPG files in " + directory
print "Are you sure? [y/n]: "
confirm = gets.chomp

if confirm.eql? "y"
  #let it run!
elsif confirm.eql? "n"
  puts "Phew, that was close!"
  exit
else
  abort "Invalid response"
  exit
end


if Dir.exists? directory
  Dir.chdir(directory)
  Dir.glob("*.JPG").sort.each_with_index do |f, index|
    extension = File.extname(f)
    #f_original = File.basename(f, extension)
    f_renamed = index.to_s.rjust(8,"0")

    File.rename(f, f_renamed + extension.downcase)
    end
else
    abort "No such directory!"
end