NAME

rand, srand − simple random-number generator

SYNOPSIS

#include <stdlib.h>

int rand (void);

void srand (unsigned int seed);

DESCRIPTION

rand uses a multiplicative congruent random-number generator with period 232 that returns successive pseudo-random numbers in the range from 0 to RAND_MAX (defined in stdlib.h). 

The function srand uses the argument seed as a seed for a new sequence of pseudo-random numbers to be returned by subsequent calls to the function rand.  If the function srand is then called with the same seed value, the sequence of pseudo-random numbers will be repeated.  If the function rand is called before any calls to srand have been made, the same sequence will be generated as when srand is first called with a seed value of 1. 

NOTES

The spectral properties of rand are limited.  drand48(3C) provides a much better, though more elaborate, random-number generator. 

SEE ALSO

drand48(3C)

  —  C Development Set