https://en.wikipedia.org/wiki/Friendly_interactive_shell#Universal_variables

Universal variables

*"Fish Shell" has a feature known as universal variables, which allow a
user to permanently assign a value to a variable across all the running
fish shells of that user. The variable value is remembered across logouts
and reboots, and updates in value are immediately propagated to all running
shells.*
 # This will make emacs the default text editor. The '-U' tells fish to
 # make this a universal variable.
 > set -U EDITOR emacs

 # This command will make the current working directory part of the fish
 # prompt turn blue on all running fish instances.
 > set -U fish_color_cwd blue

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I request that this feature may be implemented in zsh
If I have two different zsh shell instances running from same user login
and i give this following command in one zsh instance
  export -U varname=varvalue
  OR, exportglobal varname=varvalue

then i can access it in my another zsh instance running from the same
userlogin.


Zax