insta.rb

# -*- coding: utf-8 -*-

require 'open-uri'
require 'json'

query = "猫 instagr.am"
url = URI.escape("http://search.twitter.com/search.json?q=#{query}&include_entities=true")

res = open(url).read
json = JSON.parse(res)
json['results'].each do |item|
  insta_url = item['entities']['urls'][0]['expanded_url']
  m = insta_url.match(/http:\/\/instagr.am\/p\/(.+?)\//)
  id = m[1]
  puts "http://instagr.am/p/#{id}/media?size=m\n"
end