16.5. Summary

As a system administrator you are the superuser and supreme in your power. Like a god, you can create or destroy systems with just a few keystrokes. For such responsibility, a little knowledge is a dangerous thing. Understanding how the shell works and how to read, write, and modify shell scripts is crucial to your job, not only for automating everyday tasks, but for keeping the environment safe and clean for those users who depend on you. Shell scripts are run from the time the system boots to when it shuts down. They are used for system initialization, monitoring processes, installing software, checking disk usage, scheduling tasks, and so on. Beyond system chores, much of your time will be devoted to managing user accounts that start with a login shell, run initialization scripts, execute commands in a shell, and exit when the shell exits. This book was written to help all types of UNIX/Linux users understand how the major shells work and how to read and write scripts. This chapter was added to outline some of the shell scripts that pertain to system administration and how they interact with the system and its users. There are many topics that are not relevant here, but are important in the overall subject of system administration. You may find the following list of resources helpful.

Nemeth, E., Snyder, G., Seebass, S., Hein, T. R., UNIX System Administration Handbook, 3rd Ed., Upper Saddle River, NJ: Prentice Hall PTR, 2000. ISBN: 0131510517.

Nemeth, E., Snyder, G., Hein, T. R., Linux Administration Handbook, Upper Saddle River, NJ: Prentice Hall PTR, 2002. ISBN: 0130084662.

Gagné, M., Linux System Administration: A User's Guide, Boston: Addison-Wesley, 2001. ISBN: 0201719347.

Sobell, M. G., A Practical Guide to Red Hat Linux: Fedora Core and Red Hat Enterprise Linux, 2nd Ed., Pearson Education, 2004. ISBN: 0131470248.

See also www.ugu.com, Unix Guru Universe: The Official Home Page for Unix System Administrators.