lsblk will list all block devices. It lends itself well to scripting:
$ lsblk -io KNAME,TYPE,SIZE,MODEL
KNAME TYPE   SIZE MODEL
sda   disk 149.1G TOSHIBA MK1637GS
sda1  part  23.3G
sda2  part    28G
sda3  part  93.6G
sda4  part   4.3G
sr0   rom   1024M CD/DVDW TS-L632M

lsblk is present in util-linux package and is thus far more universal than proposed alternatives.