实现shell四则运算

#!/bin/bash
#
if [ $# -lt 3 ];then
   echo "para err."
   exit 1
fi

if [ "$2" == "/" ];then
   result=`echo "scale=2;$1/$3;" | bc`
   echo $result
elif [ "$2" == "+" ];then
   result=`echo "scale=2;$1+$3;" | bc`
   echo $result
elif [ "$2" == "-" ];then
   result=`bc <<< "scale=2;$1-$3;"`
   echo $result
elif [ "$2" == "*" ];then
   result=`echo "scale=2;$1*$3;" | bc`
   echo $result
else
   echo "opt err."
fi

备份地址: 【实现shell四则运算】