tcsh

Tcsh provides the built-in shell variable watch, which makes it easy to view who is logging in and out of the system.

The next few sections describe some of the most useful features tcsh provides through shell built-ins.

Tcsh is a widely available shell that most likely is not installed on your computer but is available from your YUM repository.

Thus, it makes sense to have tcsh as the login shell of choice in a secure environment.

Tcsh defines a shell variable rmstar; when turned on, it provides the user with a prompt that requests confirmation of the user's action.

It has tab-key completion of filenames (csh uses the Esc key), and it lets you switchto the directory you were last in with cd -.

Tcsh has a great feature that lets you perform such periodic execution of events with ease.

Tcsh provides the built-in variable correct, which helps you correct invalid command usage.

Tcsh provides the built-in command log, which lists the terminals affected by watch variables and who's using them (see Listing 9).

Tcsh defines the prompt built-in shell variable, which you can use to customize shell prompts.

The shell variable printexitvalue is a useful feature of tcsh that immensely aids script debugging.

This article has focused mainly on the variables that are unique to tcsh.

If tcsh isn't the login shell, the user exits to the previous shell, which isn't much help.

It will also read the . login file in your home directory and the . cshrc file as well, unless you provide a . tcshrc file.

Use rehash and which tcsh (assuming you are installing tcsh) to make sure it got installed.

If this alias is set, then tcsh executes the command that cmdcwd was aliased to after switching to a new folder.

Use the chsh command to change your shell to tcsh permanently, or type tcsh at the prompt to change your shell without logging in again.

Tcsh provides a gamut of shell variables and aliases, in addition to supporting those that csh supplies.

Note that periodic is aliased to the script checkdiskusage, which checks for disk usage and is run by tcsh every 10 minutes.

All commands and scripts described in this article have been tested with tcsh 6. 15 (see the Resources section).

The savehist variable asks tcsh to store the user's last N commands on the shell prompt.

The tcsh (pronounced tee-see-shell) can do exactly that.

Now that you have installed tcsh, you can adjust your prompt.

Use the yum command to remove tcsh.

You can solve this problem using the tcsh autologout variable.

The csh shell is okay, but tcsh doeseverything csh does and more.

For example, if you want to invoke perl and have typed in prl, tcsh lets you correct it.

Determine whether tcsh is available within an enabled YUM repository on your computer

Enhanced security in tcsh: Monitor everyone who's using the system

As in exercise 3, remove the software to manage disk space and prevent the need for any future updates to tcsh

Determine the dependencies, if any, that tcsh will require

This is shown in the following TCSH loop