Bdtyktl

I have written this command:
sudo mv /* /usr/lib/I'm not sure about this folder name/

for install flash player and many files copied to this directory /usr/lib/I'm not sure about this folder name/ and my Ubuntu doesn't work now

I'm able to use live Ubuntu. Can I use reverse command and undoing movement and repair my Ubuntu? If yes, what is the reverse command?

Update
I did. now ubuntu waiting in booting page(page with ubuntu logoo and 5 dot changing color from red to white) for half an hour.

this is fstab content

#

# Use 'blkid' to print the universally unique identifier for a

# device; this may be used with UUID= as a more robust way to name devices

# that works even if disks are added and removed. See fstab(5).

#

# <file system> <mount point>   <type>  <options>       <dump>  <pass>

# / was on /dev/sda1 during installation

UUID=1d24ddd9-b5ed-45f7-9770-9a599cecf4a3 /               ext4    errors=remount-ro 0       1

/swapfile                                 none            swap    sw              0       0```

The reverse would be

sudo mv /usr/lib/pepperflashplugin-nonfree/* /

but that is from your actual system.

From a live session you need to mount the partition. After mounting the disk cd to it using command line and then issue is from THAT directory. That would make it:

cd /media/{device}/

sudo mv usr/lib/pepperflashplugin-nonfree/* .

In between you can check with ls usr/lib/pepperflashplugin-nonfree/ if you are in the correct directory.

All commands here should be executed after verifying they are correct and valid. So use a lot of ls commands to see what the results are. After the cd for instance ls usr/lib/pepperflashplugin-nonfree/ should list your file system files that belong in /.

Good luck with this :) Anyone can make a mistake but the experts then make sure there is no mistake in repairing the problem.

From Soren A:

if you move everything from /usr/lib/pepperflashplugin-nonfree/ to / you will get the old content of /usr/lib/pepperflashplugin-nonfree/ moved to / too. It is better to move the few relevant directories one by one.

My method works but you will also move the files that should be in /usr/lib/pepperflashplugin-nonfree/ so it makes a bit of a mess of /. To clean that up you need to remove these files or do a little bit extra to start with:

So the new approach would be ...

cd /media/{device}/

ls usr/lib/pepperflashplugin-nonfree/ 

Investigate the results. Anything that looks like it belongs in the root of the device can then be mv'd to /media/{device}/. Some observations: the files in / will all belong to user "root" and group "root" and will all be directories (1st char of the result of ls will be a d) or symlinks (l)

Once you are in the live system mount the disk where Ubuntu were installed and perform a command to move back in place all files you have move.

For example, on the live system suppose the computer disk are automatically mounted on /media/disk-name enter in it with a terminal:

cd /media/disk-name

from that path execute the following command which should put every thing in place

mv ./usr/lib/pepperflashplugin-nonfree/* ./

NOTE: the ./ is not an error it is important to determinate that is the current path you are working

to be more safe use the absolute path:

mv /media/disk-name/usr/lib/pepperflashplugin-nonfree/* /media/disk-name/

An annotation: when you use wildcard character and recursive command it is recommended to think twice before run the command, for example if you execute a rm -rf ./ and you are in the root directory, you delete your entire system, moving is also dangerous! Prefer to use always the full path and a filter with the wildcard character, this to avoid distraction error could be potentially destructive.