On Wednesday, May 1, 2002, at 06:46 AM, OCNS Consulting wrote: > Of course "srand" seeds "rand". And yes, it is a good way to generate > random numbers for a one time application RUN.
The original poster is not looking for "random", he's looking for "unique". These are in many ways *opposite* requirements, as the only reliable way to get unique IDs is to use a very deterministic procedure - a simple iterator is one of the easiest and best. If you have the additional requirement that the unique values shouldn't be easily *guessable*, that becomes a very hard problem, precisely because "random" and "unique" are such poor friends. Usually people just cheat by generating a large random ID such that the probability of it being already-used is low, and then they check all the previous IDs to make sure. -Ken
