Most implementations of "srand" take an integer and will
silently truncate decimal numbers. This means "srand(42)" will
usually produce the same results as "srand(42.1)". To be safe,
always pass "srand" an integer.
1. The sum of two strings can be identical, try "rolf" and "rofl" and "flor"
2. for ( < @array > ) is dangerous nonsense, always do for ( @array ) without glob
3. if you wanna play save, try a system cmd to get a mac adress.
4. You could determine a unique seed at installation time and store it in a module MyProject::Seed you use later. Like this you have full control (just edit the module) and you only need to fiddle once with the OS for a unique key.
5. you could even request a unique key over web at installation time.