Shell Scripting Recipes: A Problem-Solution Approach

Chapter 18. Random Acts of Scripting

The generation of random numbers is too important to be left to chance.

——Robert R. Coveyou, Oak Ridge National Laboratory

Although it may often seem otherwise, computers are very predictable; they do exactly what they are told (i.e., programmed) to do. Randomness is the antithesis of predictability, and this makes the generation of random number by a computer problematic.

There are two general methods used by computers to generate random numbers: hardware and software. A hardware generator may be a dedicated device, noise from device drivers, or some other source. The software method uses a pseudo-random number generator (PRNG), so called because a mathematical formula produces the numbers. The random numbers ...