#!/bin/sh

red()
{
read -p "请输入姓名：" name
read -p "语文成绩：" yuwen
read -p "数学成绩：" shuxue
read -p "英语成绩：" waiyu

if [ -z "`echo $yuwen|sed 's/[1-9]//g'`" -a -z "`echo $shuxue|sed 's/[0-9]//g'`" -a -z "`echo $waiyu|sed 's/[0-9]//g'`" ];then
   sum=$((yuwen+shuxue+waiyu))
   ave=$((sum/3))
   echo "${name}的成绩：${sum}  平均分：${ave}"
else
   echo "成绩输入错误，请检查后重新输入"
fi
}

main()
{
red
while :
do
   read -p "是否继续输入(y-继续，n-退出): " xuanze
   if [ $xuanze == y ];then
      red
   elif [ $xuanze == n ];then
      exit
   else
      echo "选择输入错误，请重新选择"
   fi
done
}

main