chsh

• https://man7.org/linux/man-pages/man1/chsh.1.html

chsh -s /bin/ksh
Changing shell for root.

echo $SHELL
sudo su -

See also

• chsh
• Shell: Fish shell, sh, Bash, ksh, zsh, ash, PowerShell (Windows), /usr/bin/env, .hushlogin, dash, tcsh, Shell redirection,dquote, $SHELL, Google Cloud Shell, AWS CloudShell, explainshell.com, vmware_vm_shell, Nushell, Fig.io, direnv