1. \cp -rf 不需要按y确认，直接拷贝
2.判断字符串是否为空，最好加上x
result=‘‘
if [ x"$result" == x"" ];then
echo "the result is ‘ ‘ "
else
echo "the result is not ‘ ‘ "
fi
shell学习
原文：https://www.cnblogs.com/lxw123123/p/14232893.html
