This question already has an answer here:

What will happen if I change the rights and file permissions in the / ( root ) folder for all system folders to 700? Is it recommendable?

( I am the only user on the system )

marked as duplicate by heemayl, Pilot6, Eric Carvalho, Zanna, WinEunuuchs2Unix Oct 29 '16 at 0:33

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • TL;DR, it would make your system unusable. Don't do this. – Thomas Ward Oct 27 '16 at 22:55

700 denies all access to users other than the superuser (eg root).

It would effectively deny anybody running an application as a normal user, or even logging in. Applications (eg in /usr) and their configuration (in /etc) and data (in /var) need to be accessible by the user that is going to run those applications.

For any file that it is important to be inaccessible to regular users, that permission will already be set. Do not try to re-invent the security features already built into the operating system.

Not the answer you're looking for? Browse other questions tagged or ask your own question.