Interpreter for Esoteric Language '+'

local args = {...}
local file = io.open(args[1],"r")
local counter = 0
while true do
local nLine = file:lines()()
if not nLine then
break
end
if string.find(nLine,"+") then
local _, count = string.gsub(nLine,"+","+")
counter = counter + count
end
end