pages_count.rb

#!/usr/bin/env ruby
#
# Usage: pages_count.rb /path/to/docx_file.docx

require 'rubygems'
require 'zip/zip'
require 'zip/zipfilesystem'
require 'nokogiri'

# open zipfile from arguments
Zip::ZipFile.open(ARGV.first) do |zipfile|
  # xml with properties
  props_filename = 'docProps/app.xml'
  if zipfile.file.file?(props_filename)
    doc = Nokogiri::XML.parse( zipfile.file.read(props_filename) )
    pages = doc.css("Properties > Pages").first
    puts(pages.nil? ? 0 : pages.content)
  end
end