方法一:
#!/bin/bash
[ $# -ne 1 ] && exit  #判断参数个数
[ "$1" -le 0 ] && exit  #判断参数合法性
sum=0
for (( i=1;i<=$1;i=i+1 ))
do
read -p "Input number #$i: " num[$i]
sum=$((sum+num[$i]))
done
average=$((sum/$1))
echo "sum: $sum"
echo "average: $average"

#!/bin/bash
echo "请输入所要计算的数字，数字之间用空格分开"
read num_string
echo $num_string
len=0
sum=0
for i in $num_string
do
    #echo $i
    len=$((len + 1))
    sum=$((sum + i))
done
#echo $len
#echo $sum
echo "scale=2;${sum}/${len}"|bc