#!/usr/local/bin/ruby
#
# Simple ZFS Snapshotting
# Copyright (c) 2009, Jeremy Tregunna, All Rights Reserved
#
# This work `as-is' we provide.
# No warranties of any kind, express or implied.
# We've done our best,
# to debug and test.
# Liability for damages denied.
#
# Permission is granted hereby,
# to copy, share, and modify.
# Use as is fit,
# free or for profit.
# These rights, on this notice, rely.
#
# == Synopsis
#   Simple utility to take snapshots at periodic intervals defined by the user
#   with the assistance of a cron daemon.
#   This utility is meant to be run through cron, and not at the command line.
#
# == Examples
#   To take snapshots hourly, on the hour, one might use:
#
#   0 * * * * root /usr/local/bin/zfs-snapshot tank/home hourly
#
#   To recursively take a snapshot monthly, at 4:20 AM on the 1st one might use:
#
#   20 4 1 * * root /usr/local/bin/zfs-snapshot -r tank/home monthly
#
# == Usage
#   zfs-snapshot [options] filesystem_name snapshot_name
#
# == Options
#   -h, --help           Display this help message
#   -v, --version        Display the version of this script, and exit
#   -r, --recursive      Recursively create snapshots
#
# == Author
#   Jeremy Tregunna
#
# == Copyright
#   Copyright (c) 2009, Jeremy Tregunna, All Rights Reserved.
#   Released under the Poetic Licence.
#   
#   This work `as-is' we provide.
#   No warranties of any kind, express or implied.
#   We've done our best, 
#   to debug and test.
#   Liability for damages denied.
#    
#   Permission is granted hereby,
#   to copy, share, and modify.
#   Use as is fit,
#   free or for profit.
#   These rights, on this notice, rely.

require 'rdoc/usage'
require 'time'
require 'ostruct'
require 'optparse'
require 'zfs-snapshot'

SZS_VERSION = "1.0.1"
$options = OpenStruct.new
$options.recursive = false

def output_version
  puts "#{File.basename(__FILE__)} version #{SZS_VERSION}"
end

def output_help
  output_version
  RDoc::usage()
end

opts = OptionParser.new
opts.on("-h", "--help") { output_help }
opts.on("-v", "--version") { output_version; exit 0 }
opts.on("-r", "--recursive") { $options.recursive = true }
opts.parse!(ARGV)

output_help if ARGV[0].nil?

fs = Filesystem.new(ARGV[0], ARGV[1], $options.recursive)
fs.take_snapshot