Debugging using PowerShell ISE102

In my last post I gave a high level overview of how to get started with debugging in PowerShell 2.0, using the new Integrated Scripting Environment. In this installment, we are going to explore some of cmdlets that can be used to manipulate breakpoints.

First,  lets do some discovery. Whenever I am looking for cmdlets to work with something in particular, i use the get-command cmdlet with wildcards to help my search.


So from this it looks like we can get, set, enable, disable, and remove breakpoints. When we are setting breakpoints, you can specify the line and column you want to break on, but that can get really tedious. This is what the ISE does for you automatically when you toggle breakpoints. However, I find it much more useful to break when ever a variable is accessed.

Let’s use a basic function to demonstrate this.We’ll create a function foo and then set a breakpoint for the $c variable.


When we execute this code and call function foo, we get the output below. Notice that $a and $b is set, and that we break when we hit $c. One thing to note, when we specify the variable, we do not use the $ in front of the variable. This is the same as specifying the –outvariable common parameter for other cmdlets.


Last but not least, let’s take a look at how to navigate this “nested” prompt. If you type “?” or “h”, you will get the following information It is interesting that the “nested>” prompt displays this when you hit “?.” Under normal circumstances, the “?” is an alias for where-object, as we can see when we type ? at a normal prompt.


I hope this helps you with debugging your scripts.

Comments (3) -

Once you have created a PSBreakpoint for the variable c. how do you remove it? Remove-PSBreakpoint wants the pipeline position

You can use Get-PSbreakpoint and pipe it Remove-Breakpoint or use Get-Psbreakpoint and find the id of the one you want and remove just that one.

Devin Lusby 11/20/2010 7:11:27 AM

Can you set-psbreakpoint with variables in different scopes?  Or does the breakpoint apply when a variable from any scope matching the name is Read/Written?

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