# lists all IDE hard disk devices on system

for g in /proc/ide/hd*/media; do
  if test ! -e "$g"; then continue; fi
  if test xdisk = "x`cat $g`"; then
    d="${g%/*}"; d="${d##*/hd}"
    echo /dev/hd$d
  fi
done

# lists all SATA hard disk devices on system

for sd in `egrep '^[[:space:]]*[0-9]+[[:space:]]+[0-9]+[[:space:]]+sd[a-z] ' /proc/diskstats |awk '{print $3}'`; do
    echo /dev/$sd
done