This is not "about OpenBSD's implementation"

The ksy specification does not say what happens if RANDOM is
not assigned.  We've changed that behaviour, which makes most
programs safe.

We did this carefully, more than ten years ago, and have watched
for fallout.

But programs which set RAMDOM may exist, and the behaviour in
that case is somewhat specified.  We did not break those programs.

That is why our change was careful.

Your proposal affected all programs.  You provide no study, and
no justification.

To provide clarity to everyone, I recommend you reply that your
suggestion was wrong.

> localhost$ RANDOM=1; echo
>     $(echo $RANDOM $RANDOM $RANDOM) $(echo $RANDOM $RANDOM $RANDOM)
> 32422 12519 25748 12519 25748 6973
> 
> The first child starts with 32422. This is the result of RANDOM=1.
> The second child starts with 12519. Executing the child and
> change_random() calls the rand() to advance the seed. Thus 12519
> advances from 32442, which is also in the second random number
> of the first child.
> 
> "Ensure next child gets a (slightly) different $RANDOM sequence."
> As the comment explains, the next child receives a different $RANDOM
> seed than before, which advances one seed only one step forward.
> 
> Thank you for your review, I learned about OpenBSD's implementation
> due to your help.
> 
> 2026년 5월 22일 (금) 오후 10:21, Theo de Raadt <deraadt@openbsd.org>님이 작성:
> >
> > Biarder <mss091204.1@gmail.com> wrote:
> >
> > > Currently, ksh(1) uses rand(3) and modular arithmetic to calculate
> > > $RANDOM.  However, OpenBSD recommend using arc4random_uniform(3)
> > > to calculate a uniform random integer because rand function is
> > > predictable and also has modular bias when modulo operation is
> > > performed.
> >
> > Your change is incorrect.  There are situations when ksh randomness
> > must follow the rand() method.
> >
> > This is handled by not using arcrandom(), but by using the rand()
> > which _is_ arc4random() behind the scenes unless srand_deterministic()
> > is called.  And srand_deterministic() is called, in those circumstances,
> > to satisfy that requirement.
> >
> > It is in the manual page.
> >
> >      RANDOM     A random number generator.  Every time RANDOM is referenced,
> >                 it is assigned the next random number in the range 0-32767.
> >                 By default, arc4random(3) is used to produce values.  If the
> >                 variable RANDOM is assigned a value, the value is used as the
> >                 seed to srand_deterministic(3) and subsequent references of
> >                 RANDOM produce a predictable sequence.
> >
> > This work was done in 2004.  When making changes, please look at the history
> > of the code you are touching.  In this case 'grep arc4random' would have found
> > you this reference, the commit message, and this text above.  If you had
> > done 'man rand', you would have learned the rest of it.
> >
> >