Divide GPX file into segments

divider.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require 'nokogiri'

def divide(filename)
  gpx = Nokogiri::XML(File.read(filename))
  segment_count = gpx.xpath('//xmlns:trkseg').length

  segment_count.times do |i|
    # aaa.gpx -> aaa-0.gpx
    seg_filename = filename.gsub(/(.*)\.([0-9a-zA-Z]+)/, "\\1-#{i + 1}.\\2")
    seg_gpx = gpx.dup
    seg_trksegs = seg_gpx.xpath('//xmlns:trkseg')
    seg_trksegs.each_with_index { |seg_trkseg, j| seg_trkseg.remove if j != i }
    File.open(seg_filename, "w") { |file| file.puts seg_gpx.to_s }
  end
end


if ARGV.length < 1
  STDERR.puts "error: no argument"
  exit 1
end

filename = ARGV[0]
divide(filename)