List all hard drives on system (with capacities)... How?

[Ronald F. Guilmette]

I'd like to write a small program or shell script that simply lists all
of the physical hard drives attached to the local system, along with their
product identifiers and their respective capacities.

The following simple script works well for both PATA/SATA and USB hard drives,
but it does not list drive capacities:

#!/bin/sh

atacontrol list | grep ':  ad[0-9]' | sed 's/^.*:  //'
camcontrol devlist | grep '(da[0-9]' | sed -E 's/^(.*) \((da[0-9]+).*$/\2 \1/'


How can I modify the script above in order to get it to print out the
respective drive capacities?