NAME

rand, srand − simple random number generator

SYNOPSIS

srand(seed)
int seed;

rand()

DESCRIPTION

rand() uses a multiplicative congruential random number generator with period 232 to return successive pseudo-random numbers in the range from 0 to 231−1. 

srand() can be called at any time to reset the random-number generator to a random starting point.  The generator is initially seeded with a value of 1. 

SYSTEM V DESCRIPTION

rand() returns successive pseudo-random numbers in the range from 0 to 215−1. 

SEE ALSO

drand48(3), random(3)

NOTES

The spectral properties of rand() leave a great deal to be desired.  drand48(3) and random(3) provide much better, though more elaborate, random-number generators. 

BUGS

The low bits of the numbers generated are not very random; use the middle bits.  In particular the lowest bit alternates between 0 and 1. 

Solbourne Computer, Inc.  —  6 October 1989