shell脚本，计算输入给定的数，判断最大值，最小值，总和？

[root@localhost ~]# cat five.sh 
#!/bin/bash
#任意输入5个数，判断最大值，最小值，总和

s=0
read -p "please input:" num

s=$(($s+$num))
max=$num
min=$num
for i in `seq 4`
do 
      read -p "please input:" num
      s=$(($s+$num))
      
      if [ $num -le $min ];then
        min=$num
      fi

      if [ $num -ge $max ];then
         max=$num
      fi

done
echo sum:$s max:$max min:$min
[root@localhost ~]# bash five.sh 
please input:30
please input:20
please input:40
please input:10
please input:0
sum:100 max:40 min:0




[root@localhost ~]# cat 2five.sh 
#!/bin/bash
#任意输入3个数，判断最大值，最小值，总和

s=0
n=0
for i in `seq 3`
do 
      read -p "please input:" num
       expr  ${num}  +  0  1>/dev/null  2>&1  
       if   [   $?   -eq   0   ];then   
       echo   "${num}   is   a   number!"   
       else   
       echo   "${num}   is   not   a   number!"  
       exit 
        fi   

        
      s=$(($s+$num))
      [ $n -eq 0 ] && max=$num && min=$num
      n=$(($n+1))
       
      if [ $num -le $min ];then
        min=$num
      fi

      if [ $num -ge $max ];then
         max=$num
      fi

done
echo sum:$s max:$max min:$min n:$n
[root@localhost ~]# bash 2five.sh 
please input:40
40   is   a   number!
please input:20
20   is   a   number!
please input:10
10   is   a   number!
sum:70 max:40 min:10 n:3
[root@localhost ~]#