Using llGetPrimitiveParams([PRIM_TYPE]) you will get an integer reference to the type of PRIM that you are gathering information from. I know this data is posted on the llSetPrimitiveParams(list params) Section in this Wikki, but I thought as I ended up here myself looking this up that maybe it would be helpful to have these posted here as well

PRIM_TYPE_BOX 0
PRIM_TYPE_CYLINDER 1
PRIM_TYPE_PRISM 2
PRIM_TYPE_SPHERE 3
PRIM_TYPE_TORUS 4
PRIM_TYPE_TUBE 5
PRIM_TYPE_RING 6
PRIM_TYPE_SCULPT 7





Hope you all find this helpful, and that maybe it helps to save you a bit of time.
Noble Barnes