File IO

dir = "D:\\Temporary\\Lua 5_1 Reference Manual_files\\"
req = "logo.gif"
file, err = io.open(dir..req)
if err then
    error(err)
    return --this is in a function
end
print(#file:read("*a"))
-- > 82
--The file is http://prntscr.com/1pd4t6