I wanted to export my Safari Reading List on OS X, so I wrote some code to do it. I leveraged Ruby, but this methodology could be easily ported to other languages like Bash, Python, or Objective C.

First, make sure you have the plist gem:

gem install plist

Then fetch Safari's Reading List:

require "plist"
begin
  bookmarks_xml = `plutil -convert xml1 -o - ~/Library/Safari/Bookmarks.plist`
  urls = Plist.parse_xml(bookmarks_xml)["Children"].select{|e|e["Title"]=="com.apple.ReadingList"}[0]["Children"].map{|e|e["URLString"]}
  puts urls
rescue NoMethodError => e
  puts "Your reading list is empty."
end

This snippet is just a starting point; feel free to customize it for your specific use case.