aef/linebreak-cli

# encoding: UTF-8
=begin
Copyright Alexander E. Fischer <aef@godobject.net>, 2009-2013

This file is part of Linebreak::CLI.

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
=end

module Aef
  module Linebreak
    module CLI

      # Command-line sub-command for re-ncoding of files.
      class EncodeCommand < UserChoices::Command
        include UserChoices
      
        # Prepare configuration sources
        def add_sources(builder)
          builder.add_source(
            CommandLineSource, :usage,
            "Usage: #$PROGRAM_NAME encode [OPTIONS] [INPUT] [OUTPUT]\n\n",
            "Convert all linebreak encodings of a file.\n",
            "Use the environment variable LINEBREAK_SYSTEM to specify a default output encoding.\n"
          )
      
          builder.add_source(EnvironmentSource, :mapping,
            :system => 'LINEBREAK_SYSTEM'
          )
        end
      
        # Define configuration options
        def add_choices(builder)
          systems = Aef::Linebreak::BREAK_BY_SYSTEM.keys.map{|key| key.to_s}
          builder.add_choice(:system, :default => 'unix', :type => systems) do |cli|
            cli.uses_option('-s', '--system SYSTEM',
              "Output encoding system. Possible settings: #{systems.join(', ')}")
          end
      
          builder.add_choice(:files, :length => 0..2, :type => :pathname) {|cli| cli.uses_arglist}
        end
      
        # Manual option post processing
        def postprocess_user_choices
          if @user_choices[:files][0] and @user_choices[:files][0] != Pathname('-')
            @user_choices[:input] = @user_choices[:files][0].open('r')
          else
            @user_choices[:input] = STDIN
          end
      
          if @user_choices[:files][1] and @user_choices[:files][1] != Pathname('-')
            @user_choices[:output] = @user_choices[:files][1].open('w')
          else
            @user_choices[:output] = STDOUT
          end
        end
      
        # Main program
        def execute
          @user_choices[:input].each_line do |line|
            @user_choices[:output] << Aef::Linebreak.encode(line, @user_choices[:system].to_sym)
          end
      
          [:input, :output].each {|stream| @user_choices[stream].close }
        end
      end

    end
  end
end