Weather lookup service

As a first script to test out ComputerCraft, this looks up weather for any place on Earth.



Note: I stole trim(), escape(), and wrap() from the Lua wiki.

Code:

function trim(s)
  return s:match"^%s*(.*)":match"(.-)%s*$"
end
 
function escape(str)
  if str then
    str = string.gsub(str, "\n", "\r\n")
    str = string.gsub(str, "([^%w ])", function(c) return string.format("%%%02X", string.byte(c)) end)
    str = string.gsub(str, " ", "+")
  end
 
  return str
end
 
function wrap(str, limit)
  local here = 1
  return str:gsub("(%s+)()(%S+)()",
    function(sp, st, word, fi)
      if fi - here > limit then
        here = st
        return "\n" .. word
      end
  end)
end
 
function getWoeid(loc)
  local query = "SELECT * FROM geo.places WHERE text = \"" .. escape(loc) .. "\""
  local f = http.get("http://query.yahooapis.com/v1/public/yql?q=" .. escape(query) .. "&format=xml")
  local data = f.readAll()
  local woeid = string.match(data, "<woeid>([0-9]+)</woeid>")
  local name = string.match(data, "<name>([^<]+)</name>")
  f.close()
  return woeid, name
end
 
function getWeather(woeid)
  local f = http.get("http://weather.yahooapis.com/forecastrss?w=" .. woeid)
  local data = f.readAll()
  local current = string.match(data, "Current Conditions:</b><br />([^<]+)<BR />")
  local forecast = string.match(data, "Forecast:</b><BR />([^<]+)<br />")
  f.close()
  return trim(current), trim(forecast)
end
 
function printSys(message)
  term.setBackgroundColor(colors.red)
  term.setTextColor(colors.white)
  print(message)
  term.setBackgroundColor(colors.black)
end
 
function printErr(message)
  term.setTextColor(colors.red)
  print(message)
  term.setTextColor(colors.white)
end
 
function printStatus(message)
  term.setTextColor(colors.yellow)
  print(message)
  term.setTextColor(colors.white)
end
 
function printText(pr, title, text)
  pr.newPage()
  pr.setPageTitle(title)
 
  local w, h = pr.getPageSize()
  local lineNo = 1
  for token in string.gmatch(text, "[^\n]+") do
    for line in string.gmatch(wrap(token, w), "[^\n]+") do
      -- may need new page!
      if lineNo > h then
        lineNo = 1
        if not pr.endPage() then
          return false
        end
        pr.newPage()
        pr.setPageTitle(title)
        w, h = pr.getPageSize()
      end
 
      pr.setCursorPos(1, lineNo)
      pr.write(line)
      lineNo = lineNo + 1
    end
  end
 
  return pr.endPage()
end
 
local pr = peripheral.wrap("right")
local run = true
 
while run do
  -- reset
  term.clear()
  term.setCursorPos(1, 1)
  redstone.setOutput("back", false)
 
  printSys("WEATHER LOOKUP SERVICE")
  print("\nLookup the weather of any location on Earth! Enter the name of the place below.\n")
  write("Enter location: ")
 
  local loc = read()
 
  if loc ~= "quit" then
    local woeid, name = getWoeid(loc)
 
    if woeid then
      term.clear()
      term.setCursorPos(1, 1)
 
      local current, forecast = getWeather(woeid)
      printStatus("Weather for " .. name)
      print("Current: " .. current)
      print("Forecast: " .. forecast)
 
      print("")
      printStatus("Would you like a printout? [Y/N]")
      local reply = trim(read())
      if reply == "y" or reply == "Y" then
        local title = "Weather Report for " .. name
        local text = "Weather for " .. name .. "\n\nCurrent: " .. current .. "\nForecast: " .. forecast
        local ret = printText(pr, title, text)
 
        if ret then
          printStatus("Printed. Please wait a second...")
          redstone.setOutput("back", true)
          sleep(1)
          redstone.setOutput("back", false)
        else
          printErr("No ink/paper in the printer!")
        end
      end
    else
      printErr("Sorry, that location can't be found!")
    end
  else
    run = false
  end
end