Try linux command chsh
.
The detailed commands is chsh -s /bin/bash
. It will prompt you to enter your password. Your default login shell is /bin/bash
now.
The following is quoted from man page:
The cash command changes the user login shell. This determines the name of the users initial login command. A normal user may only change the login shell for her own account, the superuser may change the login shell for any account.
This command will change the default login shell permanently.