Shell脚本检测文件夹是否已被挂载的方法

方法1：

if grep -qs '/mnt/foo' /proc/mounts; then
    echo "It's mounted."
else
    echo "It's not mounted."
fi

方法2：

if mountpoint -q /mnt/foo
then
   echo "mounted"
else
   echo "not mounted"
fi