i'd like to start zsh similar to zsh -c 'my_prog option1 option2' but instead of exiting after running that command, leaving me at the propt of the invoked zsh (not wherever it is being called from). one particular use-case for this is in screenrc files, you could do something like: screen -t my_prog 0 zsh -c 'my_prog opt1 opt2' and after running that command you're left with a shell there instead of it closing.