Printer program

local printer = peripheral.find("printer")
local maxwidth, maxheight = 0

function checkInk()
 print("Ink needed")
 while printer.getInkLevel() == 0 do
  sleep(1)
 end
end

function checkPaper()
print("Wanna paper")
 while printer.getPaperLevel() == 0 do
  sleep(1)
 end
end

function writeLine(line, text)
 if text == nil then
  return line
 end
 if text:sub(1, 1) == "#" then
  text = text:sub(2)
  printer.setPageTitle(text)
  return line
 end
 printer.setCursorPos(1, line)
 if text:len() > maxwidth then
  printer.write(text:sub(1, maxwidth))
  line = writeLine(line + 1, text:sub(maxwidth + 1))
 else
  printer.write(text)
  line = line + 1
 end
 return line
end

function writePage(filename)
 if not fs.exists(filename) then
  print("There is no "..filename.." file")
  printer = false
  return
 end
 local file = fs.open(filename, "r")
 if not file then
  print("There is no "..filename.." file")
  printer = false
  return
 end


 checkInk()
 checkPaper()
 printer.newPage()
 printer.setPageTitle(filename)
 maxwidth, maxheight = printer.getPageSize()

 local ln = 1
 local line = file.readLine()
 print("Printing "..filename.." file")
 repeat
  ln = writeLine(ln, line)
  if ln > maxheight then
   return
  end
  line = file.readLine()
 until line == nil
 sleep(1)
end

while printer do
 local event, p1, p2 = os.pullEvent("redstone")
 writePage("greetings")
end