Indeed - that's how UCB Systems worked.  /tmp was a small scratch disk and anything there was suspect.  Scratch files were not a CShell feature, they were a UNIX feature, very much needed on the 16-bit address PDP-11 where it was developed.

   The idea originally became popular with Dennis's C Compiler which used it for the intermediate files between the passes on the PDP-11.   On a large public system like a University, /tmp would fill with cruft.   It was traditionally removed on reboot.  But that was not good enough for production systems that did not reboot.

    My memory is that there was a script that was similar to what Aharon suggested that ran in the early hours of the day, although before it ran it created a time_stamp_file with touch(1) set to be 6 hours previous so the script let anything under 6 hours survive using a negation on the -newer time_stamp_file clause.   

Clem

On Wed, Jun 5, 2019 at 8:51 AM <arnold@skeeve.com> wrote:
Edouard Klein <edouardklein@gmail.com> wrote:

> Hi all,
>
> I saw this on  https://old.reddit.com/r/unix :
>
> http://blog.snailtext.com/posts/no-itch-to-scratch.html
>
> It's about (the lack of) scratch files in csh. Maybe somebody here know
> what happened to the feature ?
>
> Cheers,
>
> Edouard.

>From the phraseology in the paper ("The system will remove ....") it sounds
to me like it was not a csh feature at all, but rather that the UCB
systems had a cron job to run something like

        find / -name '#*' -mtime +7 -exec rm {} \;

It's easy enough to research this in the archives, if you have the energy.
:-)

HTH,

Arnold