linux says my ruby program's syntax is wrong. How can I tell what I'm saying? Is there a way to log it?

Question

It tells me I have bad syntax on the line:

rsync -a --delete #{DIR_DATA}/ #{todays_folder}/

Here's the entire program:

#!/usr/bin/ruby
require 'rubygems'
require 'fileutils'


DIR_DATA="/mnt/apvdbs03/Public"
DIR_BKUP_ROOT="/backs/apvdbs03"
NUMBER_OF_BACKUPS = 7

def remove_last_backup_folder
last_backup_folder = File.join(DIR_BKUP_ROOT, NUMBER_OF_BACKUPS.to_s)
FileUtil.rm_rf last_backup_folder
end

def roll_backup_folders_forward
  NUMBER_OF_BACKUPS.downto(0) do |i|
    old_backup_folder = File.join(DIR_BKUP_ROOT, (i - 1).to_s)
    new_backup_folder = File.join(DIR_BKUP_ROOT, i.to_s)
    File.mv old_backup_folder new_backup_folder if File.exist(old_backup_folder)
end

def yesterdays_folder 
  @yesterdays_folder ||= File.join(DIR_BKUP_ROOT, 1)
end

def todays_folder
  @todays_folder ||= File.join(DIR_BKUP_ROOT, 0)
end

def hard_link_yesterdays_folder
  `cp -al #{yesterdays_folder} #{todays_folder}`
end

# rm -rf backup.3
remove_last_backup_folder

# mv backup.2 backup.3
# mv backup.1 backup.2
roll_backup_folders_forward

# cp -al backup.0 backup.1
hard_link_yesterdays_folder

# make todays backup
`rsync -a --delete #{DIR_DATA}/ #{todays_folder}/`

Answer 1

you haven't closed your last def, so an end needed after rsync line

Answer 2

It looks like this block is never closed:

NUMBER_OF_BACKUPS.downto(0) do |i|
  . . .
end # Missing!

Answer 3

File.join("root",1.to_s) returns "root/1", not "root.1" as the comments indicate.