Rocky basic exercise -shell script 2

Write a script , Complete the following functions ：

(1) List all disk devices recognized by the current system (2) If the number of disks is 1, The space usage information is displayed , otherwise , The space usage information on the last disk is displayed

#!/bin/bash

disk=/dev/`lsblk |egrep -o '^sd[a-z]' |tail -1`

disksum=`fdisk -l $disk|sed -rn 's/.* ([0-9]+) sectors/\1/p'`

parsum=`fdisk -l $disk |tail -1| awk '{print $3}'`

sumG=`fdisk -l $disk |sed -rn "s#^Disk /dev.* ([0-9]+) G.*#\1#p"`

used=`echo "(${disksum}-${parsum})*512/1024/1024/1024" |bc`

echo " Your disk ${disk} total ${sumG}GB, Used ${used}GB"

[[email protected] ~]# ./blk.sh

Your disk /dev/sde total 20GB, Used 16GB