RAND(3) — UNIX Programmer’s Manual
NAME
rand, srand − random number generator
SYNOPSIS
srand(seed)
int seed;
rand()
DESCRIPTION
Rand uses a multiplicative congruential random number generator with period 2**32 to return successive pseudo-random numbers in the range from 0 to 2**31−1.
The generator is reinitialized by calling srand with 1 as argument. It can be set to a random starting point by calling srand with whatever you like as argument.
7th Edition — 2/23/82