/etc/apt/sources.list" E212: Can't open file for writing

Question

I am trying to edit sources.list using vi editor but getting the following error while saving the file:

/etc/apt/sources.list\" E212: Can\'t open file for wr         


        

Answer 1

That happens to me all the time, I open a root file for writing:

Instead of losing all your changes and re-opening with sudo. See this demo of how to save those changes:

One time Setup demo to create a root owned read only file for a lower user:

sudo touch temp.txt
sudo chown root:root temp.txt
sudo chmod 775 temp.txt
whoami
el

First open the file as normal user:

vi temp.txt

Then make some changes to the file, it warns you its read only. Use this command.

:w !chmod 777 %

Then write the file:

:wq!

The permissions are expanded, and the file is saved. You need the exclamation point because you are editing a root file as a lesser user.

Explanation of what that command does:

The :w means write the file. The bang means start interpreting as shell. chmod means change permissions, 777 means full permissions everywhere. The percent means the current file name.

It applies the change. And it ask if you want to re-load. Press "O" for "Ok". Don't reload or you'll lose your changes.