Its a simple process to change the current/working shell in Linux. This could be achieved by using the commands 'exec', 'chsh'.
1). Firstly know your current shell. Execute the command
# echo $0
/bin/bash
2). Check available shells
All available shells are located in the /etc/shells file. So we can check them by:-
==========
cat /etc/shells
# /etc/shells: valid login shells
/bin/csh
/bin/sh
/usr/bin/es
/usr/bin/ksh
/bin/ksh
/usr/bin/rc
/usr/bin/tcsh
/bin/tcsh
/usr/bin/esh
/bin/dash
/bin/bash
/bin/rbash
/usr/bin/screen
================
3). To change the shell temporarily
Use exec command to change your shell temporarily as shown below.
# echo $0 ----- check current shell
/bin/bash
# exec /bin/sh ----- change shell to sh
# echo $0 ----- verify it
/bin/sh
Note: The above change is temporary. When you relogin, you’ll go back to the original shell
4). To change the shell permanently
# chsh -s /bin/sh
