Check Your Current Active Shell:

echo $0

Find Available Shells on the System:

chsh -l

the output will be similar to the following:

user@server /home/user: chsh -l
/bin/sh
/bin/bash
/sbin/nologin
/usr/bin/sh
/usr/bin/bash
/usr/sbin/nologin
/bin/tcsh
/bin/csh
/bin/zsh

Switch to an Available Shell Temporarily (given the list above, for example):

bash

tcsh

csh

zsh

Login to a Specific Shell Every Time:

Add the shell name to your .bashrc and .bash_profile files:

1) vim ~/.bashrc

2) add the shell name at the end of the file (e.g. "tcsh")

3) save the file and exit

the same can be done for .bash_profile

To switch back to your default shell (Bash), simply edit .bashrc and .bash_profile and remove the entries for any other shell you added.

NB: This method of switching shells at login will prevent you from being able to SFTP successfully into your home directory. To fix this, remove the added shell invokation entry in your .bashrc and .bash_profile files.