Beginning Shell Scripting

Chapter 13. Scripting for Administrators

The last chapter covered a major use of scripts for administrators: monitoring the systems you administer. Using MRTG, you can monitor CPU usage, available disk space, and network router throughput, among other things, but scripts come in handy in quite a few other areas. This chapter won't show you magical ways to run all of your systems. Instead, it describes how you can use scripts to improve your daily life and manage your systems with less work, including the following:

• Deciding when and where to write scripts

• Creating scripts in an organized fashion

• Scripting complicated commands

• Troubleshooting with scripts

• Removing annoyances with scripts

• Cleaning up yucky data formats

• Automating your daily work with scripts

This chapter contains some very simple scripts and some complicated scripts. In all cases, though, the goal is to show techniques, not cleverness, and to focus on generating ideas for making your work easier.

Why Write Scripts?

From an administrator's point of view, scripts enable you to do the following:

• Automate frequently run tasks

• Remember complicated command-line options and file paths

• Filter through data and respond with just the crucial items that require your attention

In these cases, scripts come in handy and, best of all, generally do not require a long time to write.

Scripting is fun. In about three minutes, you can create a useful script. The problem is that if you write all of your scripts in a totally ad hoc manner, you will end ...