chsh - change login shell
To set login shell for user1
$ chsh -s /bin/bash user1
$ chsh
Password: *****
Changing the login shell for klug
Enter the new value, or press ENTER for the default
Login Shell [/bin/bash]: /bin/sh
To change current login shell from sh to bash
$ echo $SHELL
/bin/sh
$ chsh -s /bin/bash
$ echo $SHELL
/bin/bash
regards,
T.Dhanasekar