#!/usr/local/env ruby

require 'jsonpath'
require 'json'

def usage
  puts "jsonpath [expression] (file|string)

If you omit the second argument, it will read stdin, assuming one valid JSON object
per line. Expression must be a valid jsonpath expression."
  exit!
end

usage unless ARGV[0]

jsonpath = JsonPath.new(ARGV[0])
case ARGV[1]
when nil #stdin
  until STDIN.eof?
    puts jsonpath.on(JSON.parse(STDIN.readline)).to_a.to_json
  end
when String
  puts jsonpath.on(JSON.parse(File.exist?(ARGV[1]) ? File.read(ARGV[1]) : ARGV[1])).to_a.to_json
end