No, /bin/ksh2020 is not listed in /etc/shells. In /etc/shells, ksh is
listed as /usr/bin/ksh2020.
I installed ksh2020 with the usual command: sudo apt install ksh2020
When I added to /etc/shells, the line /bin/ksh2020 and re-edited
/etc/passwd for my uid=1000, pete, to have a shell of /bin/ks
I installed U20.04 from a download from the official Canonical website;
burned to a DVD and then booted from the DVD. The installation asked all
the usual questions including asking for a first user logname. This all
went well. My installation site was a clean unused disk; installed to the
first
