Refactored to improve logging and reduce cut & paste code, bumped Debian version number.

6 files changed, 1046 insertions, 0 deletions

diff --git a/lib/byteback.rb b/lib/byteback.rb
new file mode 100755
index 0000000..b6c2ab2
--- /dev/null
+++ b/lib/byteback.rb
@@ -0,0 +1,6 @@
+require 'trollop'
+require 'time'
+require 'byteback/backup_directory'
+require 'byteback/disk_free'
+require 'byteback/util'
+require 'byteback/log'
\ No newline at end of file
diff --git a/lib/byteback/backup_directory.rb b/lib/byteback/backup_directory.rb
new file mode 100755
index 0000000..f0ceabc
--- /dev/null
+++ b/lib/byteback/backup_directory.rb
@@ -0,0 +1,103 @@
+module Byteback
+	# Represent a directory full of backups where "current"  is a subvolume
+	# which is snapshotted to frozen backup directories called e.g. 
+	# "yyyy-mm-ddThh:mm+zzzz".
+	#
+	class BackupDirectory
+		attr_reader :dir
+
+		def initialize(dir)
+			@dir = Dir.new(dir)
+			current
+		end
+
+		# Return total amount of free space in backup directory (bytes)
+		#
+		def free
+			df = DiskFree.new(@dir.path)
+			df.total - df.used
+		end
+
+		# Return an array of Times representing the current list of 
+		# snapshots.
+		#
+		def snapshot_times
+			@dir.entries.map do |entry|
+				begin
+					Time.parse(entry)
+				rescue ArgumentError => error
+					nil
+				end
+			end.
+			compact.
+			sort
+		end
+
+		# What order to remove snapshots in to regain disk space?
+		#
+		# Order backups by their closeness to defined backup times, which are
+		# listed in a set order (i.e. today's backup is more important than yesterday's).
+		#
+		BACKUP_IMPORTANCE = [0, 1, 2, 3, 7, 14, 21, 28, 56, 112]
+		def snapshot_times_by_importance
+			now = Time.now
+			snapshot_times_unsorted = snapshot_times
+			snapshot_times_sorted = []
+			while !snapshot_times_unsorted.empty?
+				BACKUP_IMPORTANCE.each do |days|
+					target_time = now + (days*86400)
+					closest = snapshot_times_unsorted.inject(nil) do |best, time|
+						if best.nil? || (time-target_time).abs < (best-target_time).abs
+							time
+						else
+							best
+						end
+					end
+					break unless closest
+					snapshot_times_sorted << snapshot_times_unsorted.delete(closest)
+				end
+			end
+			snapshot_times_sorted
+		end
+
+		# Returns the size of the given snapshot (runs du, may be slow)
+		#
+		# Would much prefer to take advantage of this feature:
+		#   http://dustymabe.com/2013/09/22/btrfs-how-big-are-my-snapshots/
+		# but it's not currently in Debian/wheezy.
+		#
+		def snapshot_size(time=snapshot_times.last)
+			`du -s -b #{snapshot_path(time)}`.to_i
+		end
+
+		def average_snapshot_size(number=10)
+			snapshot_times.sort[0..number].inject(0) { |total, time| snapshot_size(time) } / number
+		end
+
+		# Create a new snapshot of 'current'
+		#
+		def new_snapshot!
+			system_no_error("btrfs subvolume snapshot -r #{current.path} #{snapshot_path}")
+		end
+
+		def delete_snapshot!(time)
+			system_no_error("btrfs subvolume delete #{snapshot_path(time)}")
+		end
+
+		def current
+			Dir.new("#{dir.path}/current")
+		end
+
+		def snapshot_path(time=Time.now)
+			"#{dir.path}/#{time.strftime("%Y-%m-%dT%H:%M%z")}"
+		end
+
+		protected
+
+		def system_no_error(*args)
+	      args[-1] += " > /dev/null" unless @verbose
+			raise RuntimeError.new("Command failed: "+args.join(" ")) unless
+			  system(*args)
+		end
+	end
+end
diff --git a/lib/byteback/disk_free.rb b/lib/byteback/disk_free.rb
new file mode 100755
index 0000000..33952a3
--- /dev/null
+++ b/lib/byteback/disk_free.rb
@@ -0,0 +1,41 @@
+
+module Byteback
+	# Icky way to find out free disc space on our mount
+	#
+	class DiskFree
+		def initialize(mount)
+			@mount = mount
+		end
+
+		def total
+			all[2]
+		end
+
+		def used
+			all[3]
+		end
+
+		def available
+			all[4]
+		end
+
+		def fraction_used
+			disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = all
+			disk_used.to_f / disk_available
+		end
+
+		protected
+
+		def all
+			disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = 
+				df.
+				split("\n")[1].
+				split(/\s+/).
+				map { |i| /^[0-9]+$/.match(i) ? i.to_i : i }
+		end
+
+		def df
+			`/bin/df -T -P -B1 #{@mount}`
+		end
+	end
+end
diff --git a/lib/byteback/log.rb b/lib/byteback/log.rb
new file mode 100755
index 0000000..66b86ef
--- /dev/null
+++ b/lib/byteback/log.rb
@@ -0,0 +1,46 @@
+require 'logger'
+require 'syslog'
+
+module Byteback
+	# Translates Ruby's Logger calls to similar calls to Syslog 
+	# (implemented in Ruby 2.0 as Syslog::Logger)
+	#
+	class SyslogProxy
+		class << self
+			def debug(*a); Syslog.log(Syslog::LOG_DEBUG, *a); end
+			def info(*a); Syslog.log(Syslog::LOG_INFO, *a); end
+			def warn(*a); Syslog.log(Syslog::LOG_WARN, *a); end
+			def error(*a); Syslog.log(Syslog::LOG_ERR, *a); end
+			def fatal(*a); Syslog.log(Syslog::LOG_EMERG, *a); end
+		end
+	end
+
+	# Log proxy class that we can include in our scripts for some simple
+	# logging defaults.
+	#
+	module Log
+		@@me = File.expand_path($0).split("/").last
+
+		@@logger = if STDIN.tty? && !ENV['BYTEBACK_TO_SYSLOG']
+			logger = Logger.new(STDERR)
+			logger.level = Logger::DEBUG
+			logger.formatter = proc { |severity, datetime, progname, msg|
+				if severity == "FATAL" || severity == "ERROR"
+					"*** #{msg}\n"
+				else
+					"#{msg}\n"
+				end
+			}
+			logger
+		else
+			Syslog.open(@@me)
+			SyslogProxy
+		end
+
+		def debug(*a); @@logger.__send__(:debug, *a); end
+		def info(*a); @@logger.__send__(:info, *a); end
+		def warn(*a); @@logger.__send__(:warn, *a); end
+		def fatal(*a); @@logger.__send__(:fatal, *a); exit 1; end
+		def error(*a); @@logger.__send__(:error, *a); end
+	end
+end
diff --git a/lib/byteback/util.rb b/lib/byteback/util.rb
new file mode 100755
index 0000000..f9f6c62
--- /dev/null
+++ b/lib/byteback/util.rb
@@ -0,0 +1,68 @@
+require 'tempfile'
+
+module Byteback
+	module Util
+		@@lockfile = "/var/run/byteback/byteback.lock"
+
+		def remove_lockfile!
+		  begin
+		    File.unlink(@@lockfile)
+		  rescue Errno::ENOENT
+		  end
+		end
+
+		def claim_lockfile!
+			# Check the lockfile first
+			if File.directory?(File.dirname(@@lockfile))
+			  if File.exists? @@lockfile
+			    # check the lockfile is sane
+			    exist_pid = File.read(@@lockfile).to_i
+			    if exist_pid > 1 and exist_pid < (File.read("/proc/sys/kernel/pid_max").to_i)
+			      begin
+			        Process.getpgid(exist_pid)
+			        # if no exception, process is running, abort
+			        fatal("Process is running (#{exist_pid} from #{@@lockfile})")
+			      rescue Errno::ESRCH
+			        # no process running with that pid, pidfile is stale
+			        remove_lockfile!
+			      end
+			    else
+			      # lockfile isn't sane, remove it and continue
+			      remove_lockfile!
+			    end
+			  end
+			else
+			  Dir.mkdir(File.dirname(@@lockfile))
+			  # lockfile didn't exist so just carry on
+			end
+
+			# Own the pidfile ourselves
+			File.open(@@lockfile, "w") do |lockfile|
+			  lockfile.puts Process::pid
+			end
+		end
+
+		def lock_out_other_processes(name)
+			@@lockfile = "/var/run/byteback/#{name}.lock"
+			claim_lockfile!
+			at_exit { remove_lockfile! }
+		end
+
+		def log_system(*args)
+			debug("system: " + args.map { |a| / /.match(a) ? "\"#{a}\"" : a }.join(" "))
+			rd, wr = IO.pipe
+			pid = fork
+			if pid.nil? # child
+				rd.close
+				STDOUT.reopen(wr)
+				STDERR.reopen(wr)
+				# any cleanup actually necessary here?
+				exec(*args)
+			end
+			wr.close
+			rd.each_line { |line| debug(line.chomp) }
+			pid2, status = Process.waitpid2(pid, 0)
+			status.exitstatus
+		end
+	end
+end
diff --git a/lib/trollop.rb b/lib/trollop.rb
new file mode 100755
index 0000000..8264475
--- /dev/null
+++ b/lib/trollop.rb
@@ -0,0 +1,782 @@
+## lib/trollop.rb -- trollop command-line processing library
+## Author::    William Morgan (mailto: wmorgan-trollop@masanjin.net)
+## Copyright:: Copyright 2007 William Morgan
+## License::   the same terms as ruby itself
+
+require 'date'
+
+module Trollop
+
+VERSION = "1.16.2"
+
+## Thrown by Parser in the event of a commandline error. Not needed if
+## you're using the Trollop::options entry.
+class CommandlineError < StandardError; end
+  
+## Thrown by Parser if the user passes in '-h' or '--help'. Handled
+## automatically by Trollop#options.
+class HelpNeeded < StandardError; end
+
+## Thrown by Parser if the user passes in '-h' or '--version'. Handled
+## automatically by Trollop#options.
+class VersionNeeded < StandardError; end
+
+## Regex for floating point numbers
+FLOAT_RE = /^-?((\d+(\.\d+)?)|(\.\d+))([eE][-+]?[\d]+)?$/
+
+## Regex for parameters
+PARAM_RE = /^-(-|\.$|[^\d\.])/
+
+## The commandline parser. In typical usage, the methods in this class
+## will be handled internally by Trollop::options. In this case, only the
+## #opt, #banner and #version, #depends, and #conflicts methods will
+## typically be called.
+##
+## If you want to instantiate this class yourself (for more complicated
+## argument-parsing logic), call #parse to actually produce the output hash,
+## and consider calling it from within
+## Trollop::with_standard_exception_handling.
+class Parser
+
+  ## The set of values that indicate a flag option when passed as the
+  ## +:type+ parameter of #opt.
+  FLAG_TYPES = [:flag, :bool, :boolean]
+
+  ## The set of values that indicate a single-parameter (normal) option when
+  ## passed as the +:type+ parameter of #opt.
+  ##
+  ## A value of +io+ corresponds to a readable IO resource, including
+  ## a filename, URI, or the strings 'stdin' or '-'.
+  SINGLE_ARG_TYPES = [:int, :integer, :string, :double, :float, :io, :date]
+
+  ## The set of values that indicate a multiple-parameter option (i.e., that
+  ## takes multiple space-separated values on the commandline) when passed as
+  ## the +:type+ parameter of #opt.
+  MULTI_ARG_TYPES = [:ints, :integers, :strings, :doubles, :floats, :ios, :dates]
+
+  ## The complete set of legal values for the +:type+ parameter of #opt.
+  TYPES = FLAG_TYPES + SINGLE_ARG_TYPES + MULTI_ARG_TYPES
+
+  INVALID_SHORT_ARG_REGEX = /[\d-]/ #:nodoc:
+
+  ## The values from the commandline that were not interpreted by #parse.
+  attr_reader :leftovers
+
+  ## The complete configuration hashes for each option. (Mainly useful
+  ## for testing.)
+  attr_reader :specs
+
+  ## Initializes the parser, and instance-evaluates any block given.
+  def initialize *a, &b
+    @version = nil
+    @leftovers = []
+    @specs = {}
+    @long = {}
+    @short = {}
+    @order = []
+    @constraints = []
+    @stop_words = []
+    @stop_on_unknown = false
+
+    #instance_eval(&b) if b # can't take arguments
+    cloaker(&b).bind(self).call(*a) if b
+  end
+
+  ## Define an option. +name+ is the option name, a unique identifier
+  ## for the option that you will use internally, which should be a
+  ## symbol or a string. +desc+ is a string description which will be
+  ## displayed in help messages.
+  ##
+  ## Takes the following optional arguments:
+  ##
+  ## [+:long+] Specify the long form of the argument, i.e. the form with two dashes. If unspecified, will be automatically derived based on the argument name by turning the +name+ option into a string, and replacing any _'s by -'s.
+  ## [+:short+] Specify the short form of the argument, i.e. the form with one dash. If unspecified, will be automatically derived from +name+.
+  ## [+:type+] Require that the argument take a parameter or parameters of type +type+. For a single parameter, the value can be a member of +SINGLE_ARG_TYPES+, or a corresponding Ruby class (e.g. +Integer+ for +:int+). For multiple-argument parameters, the value can be any member of +MULTI_ARG_TYPES+ constant. If unset, the default argument type is +:flag+, meaning that the argument does not take a parameter. The specification of +:type+ is not necessary if a +:default+ is given.
+  ## [+:default+] Set the default value for an argument. Without a default value, the hash returned by #parse (and thus Trollop::options) will have a +nil+ value for this key unless the argument is given on the commandline. The argument type is derived automatically from the class of the default value given, so specifying a +:type+ is not necessary if a +:default+ is given. (But see below for an important caveat when +:multi+: is specified too.) If the argument is a flag, and the default is set to +true+, then if it is specified on the the commandline the value will be +false+.
+  ## [+:required+] If set to +true+, the argument must be provided on the commandline.
+  ## [+:multi+] If set to +true+, allows multiple occurrences of the option on the commandline. Otherwise, only a single instance of the option is allowed. (Note that this is different from taking multiple parameters. See below.)
+  ##
+  ## Note that there are two types of argument multiplicity: an argument
+  ## can take multiple values, e.g. "--arg 1 2 3". An argument can also
+  ## be allowed to occur multiple times, e.g. "--arg 1 --arg 2".
+  ##
+  ## Arguments that take multiple values should have a +:type+ parameter
+  ## drawn from +MULTI_ARG_TYPES+ (e.g. +:strings+), or a +:default:+
+  ## value of an array of the correct type (e.g. [String]). The
+  ## value of this argument will be an array of the parameters on the
+  ## commandline.
+  ##
+  ## Arguments that can occur multiple times should be marked with
+  ## +:multi+ => +true+. The value of this argument will also be an array.
+  ## In contrast with regular non-multi options, if not specified on
+  ## the commandline, the default value will be [], not nil.
+  ##
+  ## These two attributes can be combined (e.g. +:type+ => +:strings+,
+  ## +:multi+ => +true+), in which case the value of the argument will be
+  ## an array of arrays.
+  ##
+  ## There's one ambiguous case to be aware of: when +:multi+: is true and a
+  ## +:default+ is set to an array (of something), it's ambiguous whether this
+  ## is a multi-value argument as well as a multi-occurrence argument.
+  ## In thise case, Trollop assumes that it's not a multi-value argument.
+  ## If you want a multi-value, multi-occurrence argument with a default
+  ## value, you must specify +:type+ as well.
+
+  def opt name, desc="", opts={}
+    raise ArgumentError, "you already have an argument named '#{name}'" if @specs.member? name
+
+    ## fill in :type
+    opts[:type] = # normalize
+      case opts[:type]
+      when :boolean, :bool; :flag
+      when :integer; :int
+      when :integers; :ints
+      when :double; :float
+      when :doubles; :floats
+      when Class
+        case opts[:type].name
+        when 'TrueClass', 'FalseClass'; :flag
+        when 'String'; :string
+        when 'Integer'; :int
+        when 'Float'; :float
+        when 'IO'; :io
+        when 'Date'; :date
+        else
+          raise ArgumentError, "unsupported argument type '#{opts[:type].class.name}'"
+        end
+      when nil; nil
+      else
+        raise ArgumentError, "unsupported argument type '#{opts[:type]}'" unless TYPES.include?(opts[:type])
+        opts[:type]
+      end
+
+    ## for options with :multi => true, an array default doesn't imply
+    ## a multi-valued argument. for that you have to specify a :type
+    ## as well. (this is how we disambiguate an ambiguous situation;
+    ## see the docs for Parser#opt for details.)
+    disambiguated_default =
+      if opts[:multi] && opts[:default].is_a?(Array) && !opts[:type]
+        opts[:default].first
+      else
+        opts[:default]
+      end
+
+    type_from_default =
+      case disambiguated_default
+      when Integer; :int
+      when Numeric; :float
+      when TrueClass, FalseClass; :flag
+      when String; :string
+      when IO; :io
+      when Date; :date
+      when Array
+        if opts[:default].empty?
+          raise ArgumentError, "multiple argument type cannot be deduced from an empty array for '#{opts[:default][0].class.name}'"
+        end
+        case opts[:default][0]    # the first element determines the types
+        when Integer; :ints
+        when Numeric; :floats
+        when String; :strings
+        when IO; :ios
+        when Date; :dates
+        else
+          raise ArgumentError, "unsupported multiple argument type '#{opts[:default][0].class.name}'"
+        end
+      when nil; nil
+      else
+        raise ArgumentError, "unsupported argument type '#{opts[:default].class.name}'"
+      end
+
+    raise ArgumentError, ":type specification and default type don't match (default type is #{type_from_default})" if opts[:type] && type_from_default && opts[:type] != type_from_default
+
+    opts[:type] = opts[:type] || type_from_default || :flag
+
+    ## fill in :long
+    opts[:long] = opts[:long] ? opts[:long].to_s : name.to_s.gsub("_", "-")
+    opts[:long] =
+      case opts[:long]
+      when /^--([^-].*)$/
+        $1
+      when /^[^-]/
+        opts[:long]
+      else
+        raise ArgumentError, "invalid long option name #{opts[:long].inspect}"
+      end
+    raise ArgumentError, "long option name #{opts[:long].inspect} is already taken; please specify a (different) :long" if @long[opts[:long]]
+
+    ## fill in :short
+    opts[:short] = opts[:short].to_s if opts[:short] unless opts[:short] == :none
+    opts[:short] = case opts[:short]
+      when /^-(.)$/; $1
+      when nil, :none, /^.$/; opts[:short]
+      else raise ArgumentError, "invalid short option name '#{opts[:short].inspect}'"
+    end
+
+    if opts[:short]
+      raise ArgumentError, "short option name #{opts[:short].inspect} is already taken; please specify a (different) :short" if @short[opts[:short]]
+      raise ArgumentError, "a short option name can't be a number or a dash" if opts[:short] =~ INVALID_SHORT_ARG_REGEX
+    end
+
+    ## fill in :default for flags
+    opts[:default] = false if opts[:type] == :flag && opts[:default].nil?
+
+    ## autobox :default for :multi (multi-occurrence) arguments
+    opts[:default] = [opts[:default]] if opts[:default] && opts[:multi] && !opts[:default].is_a?(Array)
+
+    ## fill in :multi
+    opts[:multi] ||= false
+
+    opts[:desc] ||= desc
+    @long[opts[:long]] = name
+    @short[opts[:short]] = name if opts[:short] && opts[:short] != :none
+    @specs[name] = opts
+    @order << [:opt, name]
+  end
+
+  ## Sets the version string. If set, the user can request the version
+  ## on the commandline. Should probably be of the form "<program name>
+  ## <version number>".
+  def version s=nil; @version = s if s; @version end
+
+  ## Adds text to the help display. Can be interspersed with calls to
+  ## #opt to build a multi-section help page.
+  def banner s; @order << [:text, s] end
+  alias :text :banner
+
+  ## Marks two (or more!) options as requiring each other. Only handles
+  ## undirected (i.e., mutual) dependencies. Directed dependencies are
+  ## better modeled with Trollop::die.
+  def depends *syms
+    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
+    @constraints << [:depends, syms]
+  end
+  
+  ## Marks two (or more!) options as conflicting.
+  def conflicts *syms
+    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
+    @constraints << [:conflicts, syms]
+  end
+
+  ## Defines a set of words which cause parsing to terminate when
+  ## encountered, such that any options to the left of the word are
+  ## parsed as usual, and options to the right of the word are left
+  ## intact.
+  ##
+  ## A typical use case would be for subcommand support, where these
+  ## would be set to the list of subcommands. A subsequent Trollop
+  ## invocation would then be used to parse subcommand options, after
+  ## shifting the subcommand off of ARGV.
+  def stop_on *words
+    @stop_words = [*words].flatten
+  end
+
+  ## Similar to #stop_on, but stops on any unknown word when encountered
+  ## (unless it is a parameter for an argument). This is useful for
+  ## cases where you don't know the set of subcommands ahead of time,
+  ## i.e., without first parsing the global options.
+  def stop_on_unknown
+    @stop_on_unknown = true
+  end
+
+  ## Parses the commandline. Typically called by Trollop::options,
+  ## but you can call it directly if you need more control.
+  ##
+  ## throws CommandlineError, HelpNeeded, and VersionNeeded exceptions.
+  def parse cmdline=ARGV
+    vals = {}
+    required = {}
+
+    opt :version, "Print version and exit" if @version unless @specs[:version] || @long["version"]
+    opt :help, "Show this message" unless @specs[:help] || @long["help"]
+
+    @specs.each do |sym, opts|
+      required[sym] = true if opts[:required]
+      vals[sym] = opts[:default]
+      vals[sym] = [] if opts[:multi] && !opts[:default] # multi arguments default to [], not nil
+    end
+
+    resolve_default_short_options
+
+    ## resolve symbols
+    given_args = {}
+    @leftovers = each_arg cmdline do |arg, params|
+      sym = case arg
+      when /^-([^-])$/
+        @short[$1]
+      when /^--([^-]\S*)$/
+        @long[$1]
+      else
+        raise CommandlineError, "invalid argument syntax: '#{arg}'"
+      end
+      raise CommandlineError, "unknown argument '#{arg}'" unless sym
+
+      if given_args.include?(sym) && !@specs[sym][:multi]
+        raise CommandlineError, "option '#{arg}' specified multiple times"
+      end
+
+      given_args[sym] ||= {}
+
+      given_args[sym][:arg] = arg
+      given_args[sym][:params] ||= []
+
+      # The block returns the number of parameters taken.
+      num_params_taken = 0
+
+      unless params.nil?
+        if SINGLE_ARG_TYPES.include?(@specs[sym][:type])
+          given_args[sym][:params] << params[0, 1]  # take the first parameter
+          num_params_taken = 1
+        elsif MULTI_ARG_TYPES.include?(@specs[sym][:type])
+          given_args[sym][:params] << params        # take all the parameters
+          num_params_taken = params.size
+        end
+      end
+
+      num_params_taken
+    end
+
+    ## check for version and help args
+    raise VersionNeeded if given_args.include? :version
+    raise HelpNeeded if given_args.include? :help
+
+    ## check constraint satisfaction
+    @constraints.each do |type, syms|
+      constraint_sym = syms.find { |sym| given_args[sym] }
+      next unless constraint_sym
+
+      case type
+      when :depends
+        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} requires --#{@specs[sym][:long]}" unless given_args.include? sym }
+      when :conflicts
+        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} conflicts with --#{@specs[sym][:long]}" if given_args.include?(sym) && (sym != constraint_sym) }
+      end
+    end
+
+    required.each do |sym, val|
+      raise CommandlineError, "option --#{@specs[sym][:long]} must be specified" unless given_args.include? sym
+    end
+
+    ## parse parameters
+    given_args.each do |sym, given_data|
+      arg = given_data[:arg]
+      params = given_data[:params]
+
+      opts = @specs[sym]
+      raise CommandlineError, "option '#{arg}' needs a parameter" if params.empty? && opts[:type] != :flag and not opts[:allow_blank]
+
+      vals["#{sym}_given".intern] = true # mark argument as specified on the commandline
+
+      case opts[:type]
+      when :flag
+        vals[sym] = !opts[:default]
+      when :int, :ints
+        vals[sym] = params.map { |pg| pg.map { |p| parse_integer_parameter p, arg } }
+      when :float, :floats
+        vals[sym] = params.map { |pg| pg.map { |p| parse_float_parameter p, arg } }
+      when :string, :strings
+        vals[sym] = params.map { |pg| pg.map { |p| p.to_s } }
+      when :io, :ios
+        vals[sym] = params.map { |pg| pg.map { |p| parse_io_parameter p, arg } }
+      when :date, :dates
+        vals[sym] = params.map { |pg| pg.map { |p| parse_date_parameter p, arg } }
+      end
+
+      if SINGLE_ARG_TYPES.include?(opts[:type])
+        unless opts[:multi]       # single parameter
+          vals[sym] = vals[sym][0][0] rescue nil
+        else                      # multiple options, each with a single parameter
+          vals[sym] = vals[sym].map { |p| p[0] }
+        end
+      elsif MULTI_ARG_TYPES.include?(opts[:type]) && !opts[:multi]
+        vals[sym] = vals[sym][0]  # single option, with multiple parameters
+      end
+      # else: multiple options, with multiple parameters
+    end
+
+    ## modify input in place with only those
+    ## arguments we didn't process
+    cmdline.clear
+    @leftovers.each { |l| cmdline << l }
+
+    ## allow openstruct-style accessors
+    class << vals
+      def method_missing(m, *args)
+        self[m] || self[m.to_s]
+      end
+    end
+    vals
+  end
+
+  def parse_date_parameter param, arg #:nodoc:
+    begin
+      begin
+        time = Chronic.parse(param)
+      rescue NameError
+        # chronic is not available
+      end
+      time ? Date.new(time.year, time.month, time.day) : Date.parse(param)
+    rescue ArgumentError => e
+      raise CommandlineError, "option '#{arg}' needs a date"
+    end
+  end
+
+  ## Print the help message to +stream+.
+  def educate stream=$stdout
+    width # just calculate it now; otherwise we have to be careful not to
+          # call this unless the cursor's at the beginning of a line.
+
+    left = {}
+    @specs.each do |name, spec| 
+      left[name] = "--#{spec[:long]}" +
+        (spec[:short] && spec[:short] != :none ? ", -#{spec[:short]}" : "") +
+        case spec[:type]
+        when :flag; ""
+        when :int; " <i>"
+        when :ints; " <i+>"
+        when :string; " <s>"
+        when :strings; " <s+>"
+        when :float; " <f>"
+        when :floats; " <f+>"
+        when :io; " <filename/uri>"
+        when :ios; " <filename/uri+>"
+        when :date; " <date>"
+        when :dates; " <date+>"
+        end
+    end
+
+    leftcol_width = left.values.map { |s| s.length }.max || 0
+    rightcol_start = leftcol_width + 6 # spaces
+
+    unless @order.size > 0 && @order.first.first == :text
+      stream.puts "#@version\n" if @version
+      stream.puts "Options:"
+    end
+
+    @order.each do |what, opt|
+      if what == :text
+        stream.puts wrap(opt)
+        next
+      end
+
+      spec = @specs[opt]
+      stream.printf "  %#{leftcol_width}s:   ", left[opt]
+      desc = spec[:desc] + begin
+        default_s = case spec[:default]
+        when $stdout; "<stdout>"
+        when $stdin; "<stdin>"
+        when $stderr; "<stderr>"
+        when Array
+          spec[:default].join(", ")
+        else
+          spec[:default].to_s
+        end
+
+        if spec[:default]
+          if spec[:desc] =~ /\.$/
+            " (Default: #{default_s})"
+          else
+            " (default: #{default_s})"
+          end
+        else
+          ""
+        end
+      end
+      stream.puts wrap(desc, :width => width - rightcol_start - 1, :prefix => rightcol_start)
+    end
+  end
+
+  def width #:nodoc:
+    @width ||= if $stdout.tty?
+      begin
+        require 'curses'
+        Curses::init_screen
+        x = Curses::cols
+        Curses::close_screen
+        x
+      rescue Exception
+        80
+      end
+    else
+      80
+    end
+  end
+
+  def wrap str, opts={} # :nodoc:
+    if str == ""
+      [""]
+    else
+      str.split("\n").map { |s| wrap_line s, opts }.flatten
+    end
+  end
+
+  ## The per-parser version of Trollop::die (see that for documentation).
+  def die arg, msg
+    if msg
+      $stderr.puts "Error: argument --#{@specs[arg][:long]} #{msg}."
+    else
+      $stderr.puts "Error: #{arg}."
+    end
+    $stderr.puts "Try --help for help."
+    exit(-1)
+  end
+
+private
+
+  ## yield successive arg, parameter pairs
+  def each_arg args
+    remains = []
+    i = 0
+
+    until i >= args.length
+      if @stop_words.member? args[i]
+        remains += args[i .. -1]
+        return remains
+      end
+      case args[i]
+      when /^--$/ # arg terminator
+        remains += args[(i + 1) .. -1]
+        return remains
+      when /^--(\S+?)=(.*)$/ # long argument with equals
+        yield "--#{$1}", [$2]
+        i += 1
+      when /^--(\S+)$/ # long argument
+        params = collect_argument_parameters(args, i + 1)
+        unless params.empty?
+          num_params_taken = yield args[i], params
+          unless num_params_taken
+            if @stop_on_unknown
+              remains += args[i + 1 .. -1]
+              return remains
+            else
+              remains += params
+            end
+          end
+          i += 1 + num_params_taken
+        else # long argument no parameter
+          yield args[i], nil
+          i += 1
+        end
+      when /^-(\S+)$/ # one or more short arguments
+        shortargs = $1.split(//)
+        shortargs.each_with_index do |a, j|
+          if j == (shortargs.length - 1)
+            params = collect_argument_parameters(args, i + 1)
+            unless params.empty?
+              num_params_taken = yield "-#{a}", params
+              unless num_params_taken
+                if @stop_on_unknown
+                  remains += args[i + 1 .. -1]
+                  return remains
+                else
+                  remains += params
+                end
+              end
+              i += 1 + num_params_taken
+            else # argument no parameter
+              yield "-#{a}", nil
+              i += 1
+            end
+          else
+            yield "-#{a}", nil
+          end
+        end
+      else
+        if @stop_on_unknown
+          remains += args[i .. -1]
+          return remains
+        else
+          remains << args[i]
+          i += 1
+        end
+      end
+    end
+
+    remains
+  end
+
+  def parse_integer_parameter param, arg
+    raise CommandlineError, "option '#{arg}' needs an integer" unless param =~ /^\d+$/
+    param.to_i
+  end
+
+  def parse_float_parameter param, arg
+    raise CommandlineError, "option '#{arg}' needs a floating-point number" unless param =~ FLOAT_RE
+    param.to_f
+  end
+
+  def parse_io_parameter param, arg
+    case param
+    when /^(stdin|-)$/i; $stdin
+    else
+      require 'open-uri'
+      begin
+        open param
+      rescue SystemCallError => e
+        raise CommandlineError, "file or url for option '#{arg}' cannot be opened: #{e.message}"
+      end
+    end
+  end
+
+  def collect_argument_parameters args, start_at
+    params = []
+    pos = start_at
+    while args[pos] && args[pos] !~ PARAM_RE && !@stop_words.member?(args[pos]) do
+      params << args[pos]
+      pos += 1
+    end
+    params
+  end
+
+  def resolve_default_short_options
+    @order.each do |type, name|
+      next unless type == :opt
+      opts = @specs[name]
+      next if opts[:short]
+
+      c = opts[:long].split(//).find { |d| d !~ INVALID_SHORT_ARG_REGEX && !@short.member?(d) }
+      if c # found a character to use
+        opts[:short] = c
+        @short[c] = name
+      end
+    end
+  end
+
+  def wrap_line str, opts={}
+    prefix = opts[:prefix] || 0
+    width = opts[:width] || (self.width - 1)
+    start = 0
+    ret = []
+    until start > str.length
+      nextt = 
+        if start + width >= str.length
+          str.length
+        else
+          x = str.rindex(/\s/, start + width)
+          x = str.index(/\s/, start) if x && x < start
+          x || str.length
+        end
+      ret << (ret.empty? ? "" : " " * prefix) + str[start ... nextt]
+      start = nextt + 1
+    end
+    ret
+  end
+
+  ## instance_eval but with ability to handle block arguments
+  ## thanks to why: http://redhanded.hobix.com/inspect/aBlockCostume.html
+  def cloaker &b
+    (class << self; self; end).class_eval do
+      define_method :cloaker_, &b
+      meth = instance_method :cloaker_
+      remove_method :cloaker_
+      meth
+    end
+  end
+end
+
+## The easy, syntactic-sugary entry method into Trollop. Creates a Parser,
+## passes the block to it, then parses +args+ with it, handling any errors or
+## requests for help or version information appropriately (and then exiting).
+## Modifies +args+ in place. Returns a hash of option values.
+##
+## The block passed in should contain zero or more calls to +opt+
+## (Parser#opt), zero or more calls to +text+ (Parser#text), and
+## probably a call to +version+ (Parser#version).
+##
+## The returned block contains a value for every option specified with
+## +opt+.  The value will be the value given on the commandline, or the
+## default value if the option was not specified on the commandline. For
+## every option specified on the commandline, a key "<option
+## name>_given" will also be set in the hash.
+##
+## Example:
+##
+##   require 'trollop'
+##   opts = Trollop::options do
+##     opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
+##     opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
+##     opt :num_limbs, "Number of limbs", :default => 4   # an integer --num-limbs <i>, defaulting to 4
+##     opt :num_thumbs, "Number of thumbs", :type => :int # an integer --num-thumbs <i>, defaulting to nil
+##   end
+##
+##   ## if called with no arguments
+##   p opts # => { :monkey => false, :goat => true, :num_limbs => 4, :num_thumbs => nil }
+##
+##   ## if called with --monkey
+##   p opts # => {:monkey_given=>true, :monkey=>true, :goat=>true, :num_limbs=>4, :help=>false, :num_thumbs=>nil}
+##
+## See more examples at http://trollop.rubyforge.org.
+def options args=ARGV, *a, &b
+  @last_parser = Parser.new(*a, &b)
+  with_standard_exception_handling(@last_parser) { @last_parser.parse args }
+end
+
+## If Trollop::options doesn't do quite what you want, you can create a Parser
+## object and call Parser#parse on it. That method will throw CommandlineError,
+## HelpNeeded and VersionNeeded exceptions when necessary; if you want to
+## have these handled for you in the standard manner (e.g. show the help
+## and then exit upon an HelpNeeded exception), call your code from within
+## a block passed to this method.
+##
+## Note that this method will call System#exit after handling an exception!
+##
+## Usage example:
+##
+##   require 'trollop'
+##   p = Trollop::Parser.new do
+##     opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
+##     opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
+##   end
+##
+##   opts = Trollop::with_standard_exception_handling p do
+##     o = p.parse ARGV
+##     raise Trollop::HelpNeeded if ARGV.empty? # show help screen
+##     o
+##   end
+##
+## Requires passing in the parser object.
+
+def with_standard_exception_handling parser
+  begin
+    yield
+  rescue CommandlineError => e
+    $stderr.puts "Error: #{e.message}."
+    $stderr.puts "Try --help for help."
+    exit(-1)
+  rescue HelpNeeded
+    parser.educate
+    exit
+  rescue VersionNeeded
+    puts parser.version
+    exit
+  end
+end
+
+## Informs the user that their usage of 'arg' was wrong, as detailed by
+## 'msg', and dies. Example:
+##
+##   options do
+##     opt :volume, :default => 0.0
+##   end
+##
+##   die :volume, "too loud" if opts[:volume] > 10.0
+##   die :volume, "too soft" if opts[:volume] < 0.1
+##
+## In the one-argument case, simply print that message, a notice
+## about -h, and die. Example:
+##
+##   options do
+##     opt :whatever # ...
+##   end
+##
+##   Trollop::die "need at least one filename" if ARGV.empty?
+def die arg, msg=nil
+  if @last_parser
+    @last_parser.die arg, msg
+  else
+    raise ArgumentError, "Trollop::die can only be called after Trollop::options"
+  end
+end
+
+module_function :options, :die, :with_standard_exception_handling
+
+end # module