dump_shp.rb

#!/usr/bin/ruby


def read_data(io, type, bo, label = '')
	data  = nil
	bytes = nil
	value = nil

	if type == :int
		data = io.read(4)
		if bo == :big
			value = data.unpack('N')[0]
		elsif bo == :little
			value = data.unpack('V')[0]
		else
			raise ArgumentError
		end
		bytes = "%04x %04x" % data.unpack('n2')
	elsif type == :double
		data = io.read(8)
		if bo == :big
			value = data.unpack('G')[0]
		elsif bo == :little
			value = data.unpack('E')[0]
		else
			raise ArgumentError
		end
		bytes = "%04x %04x %04x %04x" % data.unpack('n4')
	else
		raise ArgumentError
	end

	str = [label, "value= #{value}", bytes, type.to_s, bo.to_s].join("\t")
	[value, str]
end




Dir.glob('*.shp').sort.each do |path|
	open(path, 'rb') do |io|
		puts '##########################################'
		puts "dump #{path}"
		puts '--------------------------------'
		puts 'File Header'
		puts '--------------------------------'
		puts read_data(io, :int, :big, 'File Code')[1]
		puts read_data(io, :int, :big, 'Unused')[1]
		puts read_data(io, :int, :big, 'Unused')[1]
		puts read_data(io, :int, :big, 'Unused')[1]
		puts read_data(io, :int, :big, 'Unused')[1]
		puts read_data(io, :int, :big, 'Unused')[1]
		puts read_data(io, :int, :big, 'File Length')[1]
		puts read_data(io, :int, :little, 'Version')[1]
		puts read_data(io, :int, :little, 'Shape Type')[1]
		puts read_data(io, :double, :little, 'Xmin')[1]
		puts read_data(io, :double, :little, 'Ymin')[1]
		puts read_data(io, :double, :little, 'Xmax')[1]
		puts read_data(io, :double, :little, 'Ymax')[1]
		puts read_data(io, :double, :little, 'Zmin')[1]
		puts read_data(io, :double, :little, 'Zmax')[1]
		puts read_data(io, :double, :little, 'Mmin')[1]
		puts read_data(io, :double, :little, 'Mmax')[1]
		puts '--------------------------------'
		puts 'Records'
		puts '--------------------------------'
		until io.eof?
			puts read_data(io, :int, :big, 'Record Number')[1]
			puts read_data(io, :int, :big, 'Content Length')[1]
			v = read_data(io, :int, :little, 'Shape Type')
			puts v[1]
			if v[0] == 0 # Null Shape
				nil
			elsif v[0] == 1 # Point
				puts read_data(io, :double, :little, 'X')[1]
				puts read_data(io, :double, :little, 'Y')[1]
			elsif v[0] == 3 || v[0] == 5 # PolyLine or Polygon
				puts read_data(io, :double, :little, 'Xmin')[1]
				puts read_data(io, :double, :little, 'Ymin')[1]
				puts read_data(io, :double, :little, 'Xmax')[1]
				puts read_data(io, :double, :little, 'Ymax')[1]
				parts = read_data(io, :int, :little, 'NumParts')
				puts parts[1]
				points = read_data(io, :int, :little, 'NumPoints')
				puts points[1]
				parts[0].times do |i|
					puts read_data(io, :int, :little, "Index of part[#{i}]")[1]
				end
				points[0].times do |i|
					puts read_data(io, :double, :little, "X[#{i}]")[1]
					puts read_data(io, :double, :little, "Y[#{i}]")[1]
				end
			end
			puts '------------'
		end
	end
end