Alternative Shells
Unless you have changed it, until now you have been using Ubuntu’s version of the Bash program called Dash (the Debian Almquist shell). Dash is based on the Ash shell by Kenneth Almquist and is almost identical to Bash in use—but is much smaller and faster.
Other shells are also available. For example, advanced users may
sometimes encounter the slight differences between Dash and Bash, and so
can choose to use Bash itself by entering chsh (for “choose shell”), entering your
password, and then pressing Enter to accept the default new shell of
/bin/bash. To change back, enter chsh again, enter your password and select
/bin/sh for your default shell. If you wish to be
certain that you are using Dash, you can enter chsh and select /bin/dash
as your shell.
You can view the list of available shells by entering the following command:
cat /etc/shellsIf you are a seasoned Linux user and prefer to use a shell that isn’t shown, from the desktop you can select System → Administration → Synaptic Package Manager and search for the term shell to list all those available. Normally, though, most users will want to stick with using the default shell.