目录：

path="/home"
#if [ ! -d ${path} ];then
if [ -d ${path} ];then
    echo dir ${path} exist!
else
    echo dir ${path} not exist!
fi

文件：

file="/home/log.txt"
if [ -f ${file} ];then
    echo file ${file} exist!
else
    echo file ${file} not exist!
fi