Using csh & tcsh

Chapter 4. The Shell Startup Files

In This chapter:

• Startup and Shutdown Files

• Getting To Know .cshr c and .login

• Modifying .cshrc and .login

• Using Variables

• Organizing Your Startup Files

• The .logout File

When you log in, your shell doesn't operate in a vacuum. Its behavior is affected by your working environment, which includes:

• Terminal settings, such as your backspace and line kill characters

• Variable values

• Aliases

• Key bindings for the command-line editor (tcsh only)

• Programmed completions (tcsh only)

All of the above are initialized in the shell startup files.

This chapter provides guidelines for modifying your startup files, explains how to set variables, and describes how to organize startup file contents. It's important to understand and know how to modify these files, since your working environment strongly influences how easily you get your work done. Much of the shell's power is tapped by using your startup files to set up your environment the way you like.

Startup and Shutdown Files

When you log in, your shell sets up its environment by reading two files named .cshrc and .login from your home directory. If the files exist, the shell executes their commands before displaying its first prompt.

tcsh reads startup files a little differently than csh. If you have a file named .tcshrc in your home directory, tcsh reads that instead of .cshrc. In order to avoid repeating a qualifying phrase throughout this handbook, it should be understood that references to .cshrc mean ".tcshrc if it exists ...