Re: [PATCH] tee: Add -q, --quiet option to not write to stdout

[Alejandro Colomar (man-pages)]

On 1/21/21 4:11 PM, Pádraig Brady wrote:
> On 21/01/2021 13:17, Alejandro Colomar wrote:
> > This is useful for using tee to just write to a file,
> > at the end of a pipeline,
> > without having to redirect to /dev/null
> >
> > Example:
> >
> > echo 'foo' | sudo tee -q /etc/foo;
> >
> > is equivalent to the old (and ugly)
> >
> > echo 'foo' | sudo tee /etc/foo >/dev/null;
>
> This was discussed last month:
> https://lists.gnu.org/archive/html/coreutils/2020-12/msg00037.html
>
> thanks,
> Pádraig

Hi all,

I'd like to continue the discussion you had in that thread:

The task we are trying to improve is:
writing stdin to a file (either truncating(overwriting) or appending).

Commonly used tools:
cat, tee, dd

- cat, as Padraig pointer out doesn't have an option to append.
- dd doesn't either (AFAIK).
- dd is quite dangerous, and I would avoid it for simple tasks.
- I read on stackexchange (I couldn't find the thread now)
  that the dd performance was lower, but I don't remember well.
- 'sh -c "exec cat > file" is even uglier than 'tee file >/dev/null'

tee is the only tool that already has the options ('-a') to precisely 
write into a file the way you want.  cat can do the same with proper 
redirection from the shell (>> / >), but I'd argue against having two 
completely different expressions for doing exactly the same thing, 
depending on if you need sudo or not:

cat > file;               ->   sudo dd of=file status=none;
cat >[>] file;            ->   sudo sh -c "exec cat >[>] file";
cat >[>] file;            ->   sudo tee [-a] file >/dev/null;
tee [-a] file >/dev/null; ->   sudo tee [-a] file >/dev/null;
tee -q[a] file;           ->   sudo tee -q[a] file;

I've sorted them from worst to best IMO.
Don't you think its quite natural to do use tee everywhere?

BTW, what a coincidence that you discussed this a month ago! :-)

Cheers,

Alex

--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/