getting bagslots from the tooltip

[saxitoxin]

Unless there is a function where I can get the total number of slots in a bag that is in my inventory (not equipped)

My guess is that I have to scan the tooltip, but I have no idea how to do that

I know that

CONTAINER_SLOTS = "%d Slot %s";

is the line in the tooltip

but not how to get %d as a value from that line in the tooltip

I would appreciate a sample code