$_tty is gone after system upgrade

$_tty is gone after system upgrade

[Ray Andrews]

I'm upgrading my system from Debian 9 to Debian 11 and my zsh is now 
whatever Debian installed (vs. old system where I was running Roman's 
pre-build). Prompt is:

     PS1=$'\n$_tty $_yel%d $_mag$cc$_nrm $ '

... which returned just the number of the current terminal on the old 
system but now

     $ echo $_tty

... returns nothing.

     $ echo $TTY

... shows " /dev/pts/3 " and of course I can strip that down to just the 
number, but still it seems strange that " $_tty " is gone.  What's the 
story?

Re: $_tty is gone after system upgrade

[Roman Perepelitsa]

On Sun, Sep 25, 2022 at 5:33 PM Ray Andrews <rayandrews@eastlink.ca> wrote:
>
> I'm upgrading my system from Debian 9 to Debian 11 and my zsh is now
> whatever Debian installed (vs. old system where I was running Roman's
> pre-build). Prompt is:
>
>      PS1=$'\n$_tty $_yel%d $_mag$cc$_nrm $ '
>
> ... which returned just the number of the current terminal on the old
> system but now
>
>      $ echo $_tty
>
> ... returns nothing.

I don't recall any version of zsh setting _tty. Debian 9 doesn't set it either.

    % docker run -e TERM --rm -it debian:stretch bash -c '
      apt-get update && apt-get install -y zsh && zsh -c "typeset -p TTY _tty"'
    [...]
    zsh:typeset:1: no such variable: _tty
    typeset TTY=/dev/pts/0

If you were using https://github.com/romkatv/zsh-bin, that would be
zsh 5.8. It doesn't set _tty.

In any case, it seems better to use ${TTY:t} given that this parameter
is (and has been for a long time) documented and working as intended.

Roman.

Re: $_tty is gone after system upgrade

[Ray Andrews]

On 2022-09-25 08:42, Roman Perepelitsa wrote:
>
> I don't recall any version of zsh setting _tty. Debian 9 doesn't set it either.
Ah!  Dumb question, it was my own variable.  I have this:

     if [[ $TERM == 'xterm' ]]; then

         _tty="${TTY#/dev/pts/}"

... but what's changed is the $TERM used to be "xterm" but is now 
"xterm-256color"  so that's where the problem is.  Easy to fix.

Do we have some way of erasing a question entirely from the site?  A 
question like this one shouldn't even have been asked, it's just 
pollution.  Thanks Roman.

Re: $_tty is gone after system upgrade

[Peter Stephenson]

On Sun, 2022-09-25 at 08:51 -0700, Ray Andrews wrote:
> On 2022-09-25 08:42, Roman Perepelitsa wrote:
> > 
> > I don't recall any version of zsh setting _tty. Debian 9 doesn't set it either.
> 
> Ah!  Dumb question, it was my own variable.  I have this:
> 
>      if [[ $TERM == 'xterm' ]]; then
> 
>          _tty="${TTY#/dev/pts/}"
> 
> ... but what's changed is the $TERM used to be "xterm" but is now 
> "xterm-256color"  so that's where the problem is.  Easy to fix.
> 
> Do we have some way of erasing a question entirely from the site?  A 
> question like this one shouldn't even have been asked, it's just 
> pollution.  Thanks Roman.

Actually, I disagree --- I think a reminder that names of terminals change
and that that may have consequences for shell code is very useful.

pws