sed 变量在shell引用

#!/bin/bash
ZipName=`ls -lt /data/office_services/*.zip | head -1 | awk -F"/" '{print $NF}'`
date=`date +%Y%m%d`
filedate=`ls -lt /data/office_services/*.zip | head -1 | awk -F"/" '{print $NF}' | stat *.zip|awk -F"[-:. ]+" '/Change/{print $2$3$4}'`
read -p "Enter your LastVersion:" LastVer
read -p "Enter your NewVerVersion:" NewVer
cp -a ${LastVer} ${NewVer}
sleep 10
sed -i "s/$LastVer}/$NewVer/g" start.sh
if [[ $filedate==$date ]]
then
echo -e "解压进行中请稍等。。。。。。。。。。。"
unzip -qo ${ZipName}
sleep 5
sh ./start.sh
else
echo -e "当前文件不等于当天的时间,exit。"
exit 0
fi