问题：
I would like to change permissions of a folder and all its sub folders and files in one step (command) in Linux. 我想在Linux中一步（命令）更改文件夹及其所有子文件夹和文件的权限。
I have already tried the below command but it works only for the mentioned folder: 我已经尝试过以下命令，但它仅适用于上述文件夹：
chmod 775 /opt/lampp/htdocs
Is there a way to set chmod 755 for /opt/lampp/htdocs and all of its content including subfolders and files? 有没有办法为/opt/lampp/htdocs设置chmod 755及其所有内容，包括子文件夹和文件？
Also, in the future, if I create a new folder or file inside htdocs , how can the permissions of that automatically be set to 755 ? 此外，将来，如果我在htdocs创建一个新的文件夹或文件，它的权限如何自动设置为755 ？
I had a look at this link too: 我也看过这个链接：
http://stackoverflow.com/questions/3740187/how-to-set-default-chmod-in-linux-terminal http://stackoverflow.com/questions/3740187/how-to-set-default-chmod-in-linux-terminal
解决方案：
参考一： https://stackoom.com/question/Fgz2/如何在Linux中一步更改文件夹及其所有子文件夹和文件的权限-关闭参考二： https://oldbug.net/q/Fgz2/How-do-I-change-permissions-for-a-folder-and-all-of-its-subfolders-and-files-in-one-step-in-Linux-closed
来源：oschina
链接：https://my.oschina.net/u/3797416/blog/4475603