random

OS/161 Reference Manual

Name

random - pseudorandom number generation

Library

Standard C Library (libc, -lc)

Synopsis

#include <stdlib.h>

long
random(void);

void
srandom(unsigned long seed);

Description

random returns a number between 0 and 0x7fffffff. This number is selected using a rather complex generator which is believed to generate randomness of an acceptable (though not cryptographic) quality. Unlike with some generators, all bits of the values returned are random.

srandom initializes the generator state based on the passed-in seed. If srandom is not called, the sequence of numbers returned by random is the same as if srandom had been called with a seed of 1.

The symbolic constant RAND_MAX is provided to hold the maximum value 0x7fffffff. This is technically incorrect as the name RAND_MAX is properly part of a different random number interface.

The implementation of random and srandom used in OS/161 is software developed by the University of California, Berkeley and its contributors.