I've got a question about something that always bothered me about Linux. On Windows, if any of the system files become damaged, you can just reinstall the system files, without having to re-format your disk,which is a great option.Is there anything similar on Linux?I run a Raspbian Distro on my Raspberry Pi, and my system became damaged AGAIN, after another power cut. It was running a Netatalk server working as a TimeMachine for Mac. After a power cut, system would not boot, I had to run fsck.ext4 on the filesystem manually to fix it - and it had a LOT of errors to fix. After running that, the system would boot, but there are strange errors around - it does not know the name of the machine, so it appears as pi@(unknown), some basic system programs like ls or sudo give me permission denied errors, I have plugged in the card to another computer and manually set the right permissions on sudo, but now when I run it it gives me Segmentation Fault error, so the file is clearly damaged.Now my point is - it would be a lot of pain to reinstall everything again. Is there an option to fix it by reinstalling all system files without breaking all of my custom setup for netatalk? 
Is it possible to repair Linux system files? Or is reinstall the only option?
linux;raspberry pi