Random strings in Lua

string.random.lua

math.randomseed(os.time())

local charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"

function string.random(length)
  if length > 0 then
    return string.random(length - 1) .. charset:sub(math.random(1, #charset), 1)
  else
    return ""
  end
end

abc = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","r","s","t","u","v","z","y","w","q","1","2","3","4","5","6","7","8","9","0"}
local string = ""
function GeneratedString() 
    for i=1,35 do
        rdm = math.random(1,35)
        string = string..abc[rdm]
    end
    return string
end