gdb tiny_linked_list
break main
run
disas
break *0x(address of call to printList)
[example: break *0x400612]
continue

print topOfArray
print topOfArray.data
print topOfArray.next

print headOfList
print headOfList.data
print headOfList.next

print *(headOfList.next)
print *((headOfList.next).next)
print *(((headOfList.next).next).next)
print *(headOfList.next.next.next)

print headOfList
print *headOfList
print (char) *headOfList
print (float) *headOfList
print (struct node) *headOfList
print ((struct node) *headOfList).next
print *(((struct node) *headOfList).next)

print topOfArray
print topOfArray@10
print *topOfArray@10

Extras:
l
[shows source code near current point]
b 65
[break at .c file line 65]