Read only the last characters of a LUA string

Read 2 last characters:

str = "12/5/2015;00:00:05;90"
 print(string.sub(s, -2))

Break into 3:

str = '12/5/2015;00:00:05;90'
for word in string.gmatch(str, '([^;]+)') do
    print(word)
end

Placing each part in an Array:

 a = {} -- array 1
 b = {} -- array 2
 c = {} -- array 3

str = '12/5/2015;00:00:05;90'
op = 0
for word in string.gmatch(str, '([^;]+)') do
   op = op+1
   if op == 1 then
      a[1] = word
   elseif op == 2 then
      b[1] = word
   elseif op == 3 then
      c[1] = word
   end
end
print(a[1])
print(b[1])
print(c[1])

You can run the code and test online here

Try this:

s = "12/5/2015;00:00:05;90"
print(s:match(".*;(.+)$"))

.*; advances to the last ; .

(.+)$ captures and returns the remainder to the end of the string.