Can not root: after removing ZSH and returning to default bash

Question

I can not $ sudo su everytime, I enter the command, the terminal says :

can not execute /usr/bin/zsh no such file or directory

How to return to default bash of Ubuntu and make bash as default bash?

Answer 1

First remove the symlink and make a new symlink that makes the default to previous bash

sudo ln -sv /bin/bash /bin/sh

Exit the terminal, and start a new terminal.

Now, change root's shell. Edit the passwd file - Start any editor and search for zsh.

I used vim - $ sudo vim /etc/passwd

Searched /zsh. For me it was on the first line:

root:x:0:0:root:/root:/usr/bin/zsh

changed

root:x:0:0:root:/root:/bin/bash

Esc, :wq, Enter - This is for saving and exiting Vim.

For other editors like gedit and nano, just search for zsh, edit line, then save and exit.

Then exit Bash and restart your PC.