How to return the rights to files?

Question

linux

I entered the command sudo chmod -r 774 var/www/
The numbers in the command can be 744, I don’t remember exactly.
Icons began to disappear, I realized that I messed up but it was too late. I closed the terminal and rebooted the computer and here is the text
Apparently blocked access rights.
What command to restore rights without logging in? If there are any options for solving this problem without reinstalling the OS?
On ubuntu only a month, please do not judge strictly.

Answer 1

Apparently it was "/var".
Unfortunately, in Ubuntu/Debian, unlike RPM-based distro (rpm --setperms), there is no easy way to fix this.
Here https://hyperlogos.org/page/Restoring-Permissions-... comrade found something like a workaround.

Answer 2

Even if you set a complete ban on the /var/www/ directory, the OS itself should not stop loading from this. Didn't do anything else.