function split(str, pat)
   local t = {}
   local fpat = (.-) .. pat
   local last_end = 1
   local s, e, cap = strfind(fpat, 1)
   while s do
      if s ~= 1 or cap ~=  then
         table.insert(t,cap)
      end
      last_end = e+1
      s, e, cap = strfind(fpat, last_end)
   end
   if last_end = #str then
      cap = strsub(last_end)
      table.insert(t, cap)
   end
   return t
end

--tbl = split('c:\\Windows\\System32\\AdvancedInstallers\\cmiadapter.dll','[\\/]+')