Rafay Khan's questions

While building OpenCV I accidentally linked the wrong header file.

Instead of linking videodeh.h like this :

$ sudo apt-get install libdc1394-22 libdc1394-22-dev libxine2-dev libv4l-dev v4l-utils
$ cd /usr/include/linux
$ sudo ln -s -f ../libv4l1-videodev.h videodev.h

I did accidentally linked videodev2.h, like this:

$ sudo apt-get install libdc1394-22 libdc1394-22-dev libxine2-dev libv4l-dev v4l-utils
$ cd /usr/include/linux
$ sudo ln -s -f ../libv4l1-videodev.h videodev2.h

Now when I unlinked videodev2.h (sudo unlink videodev2.h) it removed the hearder file from /usr/include/linux.

I tried reinstating videodev2.h by installing libv4l-dev and v4l-utils (sudo apt-get install libv4l-dev v4l-utils) but to no avail. I also just straight up copied videodev2.h from here, but that gives me this error while building opencv:

In file included from /home/rafay/opencv/modules/videoio/src/cap_v4l.cpp:235:
/usr/include/linux/videodev2.h:63:10: fatal error: linux/compiler.h: No such file or directory
 #include <linux/compiler.h>
          ^~~~~~~~~~~~~~~~~~
compilation terminated.

Any help that can reinstate videodev2.h without reinstalling Ubuntu will be appreciated.

I need to remove OpenVPN Access Server completely from my system. I installed it with root access(sudo -i) using the following commands from the OpenVPN website:

apt update && apt -y install ca-certificates wget net-tools gnupg
wget -qO - https://as-repository.openvpn.net/as-repo-public.gpg | apt-key add -
echo "deb http://as-repository.openvpn.net/as/debian bionic main">/etc/apt/sources.list.d/openvpn-as-repo.list
apt update && apt -y install openvpn-as

There are unfortunately no clear instructions on how to remove the program and all the associated things installed with it. Can someone guide me on how to go about this?