4.3BSD - /usr/man/cat3/rand.0

RAND(3C)                                                              RAND(3C)


NAME
       rand, srand - random number generator

SYNOPSIS
       srand(seed)
       int seed;

       rand()

DESCRIPTION
       The  newer  random(3)  should be used in new applications; rand remains
       for compatibilty.

       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.

SEE ALSO
       random(3)


7th Edition                   September 29, 1985                      RAND(3C)