Re: Executing command on reattaching to screen session

[Thorsten Kampe <thorsten@thorstenkampe.de>]

* Bart Schaefer (Thu, 06 Feb 2014 20:01:41 -0800)
> On Feb 6,  7:27pm, Thorsten Kampe wrote:
> } Every time I login, /etc/motd is displayed. Since I hardly ever
> } log  out and in, I'd like to have the same functionality when
> }  reattaching 
> 
> Perhaps a better way to do this is to put something in your precmd
> hooks so that the /etc/motd is shown when it has changed?  E.g.,
> 
>   latest_motd() {
>     if [[ /etc/motd -nt ~/.last_motd ]]
>     then
>       cp --preserve=timestamps /etc/motd ~/.last_motd
>       cat ~/.last_motd
>     fi
>   }
>   add-zsh-hook precmd latest_motd

Thanks for the suggestion. The information has to be displayed 
regularly even if it hasn't changed.

I was unsure whether to handle the task on the terminal (multiplexer) 
or on the shell level. As far as I can see, the shell doesn't get 
"notified" when I reattach, so it has to be done on the screen/tmux 
level.

The best "approximation" I found so far is to display not on 
reattaching but on idle: I changed the byobu backend to screen, then 
I created a .screenrc in ~/.byobu containing

blankerprg  zsh -c "while true; do cat /etc/motd.d; sleep 30; clear; 
done"
idle        600

That uses screen's screensaver functionality to display text I would 
normally only see on login on a blank screen.

Thorsten