Accidently deleted /usr/lib, how do I restore it?

Question

I know this is something I shouldn't do, but it happened(Ubuntu 12.04.1 LTS) as a root user I deleted /usr/lib folder. Any ideas how to restore it?

Answer 1

There are tools that might help you undelete the files, but usually it's a slow and mostly manual process. Search engines are your friends.

It may be easier to boot up a live CD or USB, mount your system's root partition, then copy /usr/lib to /mnt/{root.drive}usr/lib, but you will only get the default lib files and not what you may have added.

I think the best option is to reinstall the OS. Of course, you will want your data on a separate partition that is not formatted during install, good practice IMHO.

Answer 2

Supposing apt-get still works you can try to use dpkg to get a listing of the packages that have files there and then install them with apt-get. You can use this Ruby script, but the same idea can be implemented in python or bash:

raw_pkgs = `dpkg --get-selections`.split("\n")
need_reinstall = []

path="/usr/lib"

raw_pkgs.each do |x|
    pkg = x.split(" ")[0]
    if `dpkg -L #{pkg}`.include? path
        puts "-> #{pkg} has files in #{path}"
        need_reinstall << pkg
    end
end
puts "\nYou need to reinstall #{need_reinstall.size} packages:"
puts "\tsudo apt-get install --reinstall " + need_reinstall.join(" ")

It is a little of a brute-force solution and will take some time (in my system the listing was ~65% of the total packages installed...), but should work.

Answer 3

Then create an ubuntu USB boot. Then boot to "try ubuntu" mode. Then mounting your disk to access /usr/lib folder Access files in Home directory from live mode . Copy /usr/lib from other computer to your. Restart. Then your computer can work almost normally with almost all basic function. You can install missing libs later

Answer 4

import subprocess
from functools import cache


def main():
    run_cmd = subprocess.run(["dpkg", "--get-selections"], capture_output=True)
    path = "/usr/lib/python3"
    output = {x for x in run_cmd.stdout.decode().split("\n")}
    app_box = []

    for x in output:
        pkg = x.split("\t")[0]
        the_process = {x for x in subprocess.run(["dpkg", "-L", pkg], capture_output=True).stdout.decode().split("\n")}
        if path in the_process:
            print(f"-> {pkg} has file in {path}")
            app_box.append(pkg)
        else:
            print(f"-> {pkg} has no file in {path}")

    print(f"you need to reinstall {len(app_box)} package")
    print(f"\tsudo apt install --reinstall {' '.join(app_box)}")

if __name__ == "__main__":
    main()

If you are wondering about the python version of the answer @Salem provided............ Here is it. well, not that efficient but it works LOL.