xspfjoiner.rb

require 'rexml/document'
require 'rexml/formatters/pretty'

# xspfjoiner.rb
# (C) itochan 2017
# License: MIT
# Usage: ruby xspfjoiner.rb [xspf_file ...]
# Output: Merged xspf file

URL_LENGTH = 2048

out_xspf = REXML::Document.new
out_xspf << REXML::XMLDecl.new('1.0', 'UTF-8')

out_xspf.add_element('playlist', 'version' => '1', 'xmlns' => 'http://xspf.org/ns/0/')
out_xspf.root.add_element('trackList')

ARGV.each do |file|
  xspf = REXML::Document.new(File.open(file))
  track = xspf.elements['/playlist/trackList/track']
  out_xspf.elements['/playlist/trackList'].add_element(track)
end

pretty_formatter = REXML::Formatters::Pretty.new(0)
pretty_formatter.compact = true
pretty_formatter.width = URL_LENGTH
pretty_formatter.write(out_xspf, STDOUT)