From: George Michaelson <ggm@algebras.org>
To: Richard Salz <rich.salz@gmail.com>
Cc: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] sh and goto
Date: Wed, 16 Dec 2020 14:41:46 +1000 [thread overview]
Message-ID: <CAKr6gn1gBXtDNjfciVKJ_xO9Bos=O2aJubL2jSx7__XvS4uZKg@mail.gmail.com> (raw)
In-Reply-To: <CAFH29tpKsEr1-X_Xi75=oUr_6RdJUjbxyR3=Dn447g0LtL9k4A@mail.gmail.com>
Great solution. Not entirely "side effect free.."
On Wed, Dec 16, 2020 at 2:30 PM Richard Salz <rich.salz@gmail.com> wrote:
>
>
>> trap is a setjmp/longjmp type outcome. You pop up in a call you didn't
>> exactly "plan" for (well you did: you wrote it. But you don't know the
>> entry state which led you there, unlike normal program flow) -well, it
>> is.. because you get there.
>
>
> I once won a Usenix contest for using /bin/sh to test your reflexes.
>
> trap "ls | wc ; exit 0" 0 1 2 3 15
> ls * | wc -l
> echo "Type ^C; see how close you can make your number match"
> rm -rf * | wc -l
> kill -1 $$ # For those without "trap 0"
>
next prev parent reply other threads:[~2020-12-16 4:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 16:02 srbourne
2020-12-15 19:44 ` Ken Thompson
2020-12-15 23:27 ` George Michaelson
2020-12-16 4:30 ` Richard Salz
2020-12-16 4:41 ` George Michaelson [this message]
2020-12-16 4:01 M Douglas McIlroy
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