Section 5.2. Selecting a Shell

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5.2. Selecting a Shell

When you first get an account on a Linux machine, the account will use Bourne Again Shell (/bin/bash) as its login shell. But using bash is not a requirement, you can choose any shell to be your login shell.

To change your default login shell, use the chsh utility (Figure 5-2).

Utility: chsh

chsh allows you to change your default login shell. It prompts you for the full pathname of the new shell, which is then used as your shell for subsequent logins.

In order to use chsh, you must know the full pathnames of the shells (Figure 5-3).

Figure 5-3. Common shell locations.

Shell	Full pathname
Bash	/bin/bash (or /bin/sh)
Korn	/bin/ksh
C	/bin/tcsh (or /bin/csh)

In the following example, I changed my default login shell from Bash to a C shell:

$ chsh                 ...change the login shell. Changing shell for glass Password:              ...must verify you are who you say. New shell [/bin/bash]: /bin/tcsh    ...enter full pathname. $ ^D                   ...terminate login shell. login: glass           ...log back in again. Password:              ...secret. % _                    ...this time I'm in a C shell. 

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Another way to find out the full pathname of your login shell is to type the following:

$ echo $SHELL   ...display the name of my login shell. /bin/tcsh       ...full pathname of the C shell. $ _ 

This example illustrated the echo shell command and a shell variable called SHELL. Both of these new facilitiesechoing and variablesare discussed later in this chapter.