Windows PowerShell™ 2 For Dummies®

Chapter BC1. Handling Exceptions

In This Chapter

• Addressing errors the old way

• Getting to know exceptions

• Doing something with an exception

• Generating your own exceptions

It'd really be nice if all the scripts you write work flawlessly each and every time, and you don't have to worry about running into any errors. When you write a script to automate some task that you're just going to run once, you usually write it to do only what you need it to do — nothing more. For scripts that you'll reuse — or, more important, that others will use — it's always a good idea to build in lots of error handling so that your script doesn't do anything you don't expect it to.

In this chapter, you practice techniques for dealing with runtime errors in your scripts through exception handling. This is really the recommended method for writing error handling code in Windows PowerShell because it applies the same concepts used by the different programming languages used in the .NET framework. You get to see for yourself how much more efficient it is to use it over traditional error handling techniques once you understand the basic concepts for how exception handling works.

Handling Errors the Old-Fashioned Way

The traditional way of handling errors, and the method used most in other Windows scripting languages, involves checking for an error condition and then acting on it if an error is detected. If the script is supposed to read in a file, for example, you'll usually see some code to check whether the file ...