Also, I have another question

The command

disklist=$(format </dev/null | nawk '/[0-9]+\. c[0-9]/ { print $2}')

worked perfectly.

However, disklist is going to give me the list of all disks attached to
the system. I need only the root disk, or the disk that the machine
boots from? Is this always the first entry (or the zeroeth entry)?

Thanks,
Anoop