Use chmod command with caution

When Tomcat was configured last night, it was mistakenly used under/usr/share /.
Chmod command

I didn't pay attention to it at the time. I just wanted to give some permissions to common users to the Tomcat directory below it.

When the system is started and restarted, the logon interface disappears and an error prompt dialog box appears, all

I didn't know what happened at that time. I suddenly thought of the previous font beautification before going to bed last night and forgot to grant permissions.

In the recover mode, this prompt is displayed: cocould not init font path element/usr/share/fonts/X11 /..

So I changed the permission: chmod-r 755/usr/share/font/
========================================================== ==============================
-R indicates that sub-directories also change permissions. 755 indicates the permissions of users, user groups, and other users.

R --- read ------ 4
W -- write ----- 2
X --- execute -- 1