Did the shell ( terminal ) change in Catalina?
These are two completely different things that have nothing to do with each other, so let's address them separately:
Did the terminal change in Catalina?
No. There might have been updates (although I don't think so), but there have not been any fundamental changes.
Did the shell change in Catalina?
Catalina still ships with the same shells that High Sierra did. There were probably some updates (I haven't checked), but no updates that fundamentally change the behavior of the shells. Also, there were no new shells added and no shells removed.
The one thing that has changed, is the default interactive login shell for newly-created user accounts, which is now Zsh instead of Bash. The reason for that is that macOS ships with a really old version of Bash, because Apple doesn't want to ship code under the GPLv3, so they ship the last version of Bash that is still under the GPLv2. Thus, Apple is trying to move users away from Bash, at least for interactive use.
Note, that this applies only to
- the interactive login shell for a user, other shells are unchanged,
- the default, the user or administrator can still change it if they wish,
- newly-created user accounts, existing accounts will not be migrated automatically.
It is not quite clear why and how your login shell was changed to Zsh. That shouldn't have happened. It should only be changed for newly-created accounts, not for existing ones.
# set cursor to display path and command count
PS1="<: \w | \! :> "
Now my cursor actually has a
\w and a
\! in it. Before in my older Mac from about 4 years ago it would show the path and command count.
That snippet has nothing to do with the cursor. It changes the prompt. The cursor doesn't even have anything to do with the shell, it is managed by the terminal emulator.
The equivalent Zsh prompt escape sequences to the Bash ones you showed, would be:
%/: current working directory
%~: current working directory; if the path starts with the home directory, replace the prefix with
%!: current history event number