bug#70477: closed (tail command does not hang on /dev/random)

[GNU bug Tracking System]

Your message dated Fri, 19 Apr 2024 21:52:20 -0700
with message-id <cd5e3958-dcd3-4928-a5d4-7e57825228f9@cs.ucla.edu>
and subject line Re: bug#70477: tail command does not hang on /dev/random
has caused the debbugs.gnu.org bug report #70477,
regarding tail command does not hang on /dev/random
to be marked as done.

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70477: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=70477
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> --- Begin Message ---
>
>
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> Subject: 
>
> tail command does not hang on /dev/random
>
>
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>
> Date: 
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> Fri, 19 Apr 2024 21:40:35 +0300
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> The following command hangs indefinitely, as expected:
>
>         tail -c 4096 /dev/random
>
> The following command immediately returns 4097 bytes, unexpectedly:
>
>         tail -c 4097 /dev/random
>
> Details:
> - Source code obtained from: git://git.sv.gnu.org/coreutils
> - Commit id: 9ab1f9db94479eca4dd2c29b4e21550ff2bcd5bb
> - System:
>
>         $ uname -a
>         Linux zinc 6.1.0-20-amd64 #1 SMP PREEMPT_DYNAMIC Debian
> 6.1.85-1 (2024-04-11) x86_64 GNU/Linux
>
>
>
> --- End Message ---

--- Begin Message --- Subject: Re: bug#70477: tail command does not hang on /dev/random Date: Fri, 19 Apr 2024 21:52:20 -0700 User-agent: Mozilla Thunderbird

On 2024-04-19 11:40, Ionut Nicula wrote:

The following command hangs indefinitely, as expected:

         tail -c 4096 /dev/random

The following command immediately returns 4097 bytes, unexpectedly:

         tail -c 4097 /dev/random

Thanks for the bug report. Although the two commands should behave similarly, neither should loop: they should both output the requested number of random bytes. Similarly for /dev/zero. I installed the attached patch to do that.

0001-tail-avoid-infloop-with-c-on-dev-zero.patch
Description: Text Data

--- End Message ---