Advanced Windows PowerShell Scripting Video Training

Advanced Windows PowerShell Scripting Video Training
Advanced Windows PowerShell Scripting Video Training

Monday, February 23, 2015

How to Tell a Script if it is Running in the Shell or ISE?

Sometimes some code just does not work the same in the console as it does in the ISE.  Here is an example.

ISE

PS C:\> [CHAR]50000

Shell

image

All that we did was asked to display the character associated with the ASCII code 50000.  As you can see, the ISE can display it, but the Shell cannot.  So what if you need to alter the behavior of your code or just out right exit your code based on if your code is running in the Shell or ISE.  Well, here is a little function that you can add to your code.

1

2

3

4

5

Function Test-ISEHost

{

    If((Get-host).Name -like "*ISE*") {Write-Output $True}

    Else {Write-Output $False}

}

 

 

Since I run a lot of my code from the ISE, I am testing to see my code is using the ISE or not.  This code will return TRUE if running in the ISE and False otherwise.  With this Boolean value, you can make decisions.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

Function Do-Something

{

    Function Test-ISEHost

    {

        If((Get-host).Name -like "*ISE*") {Write-Output $True}

        Else {Write-Output $False}

    }

 

    # Use the Test-ISEHost function to determine if

    # execution should continue.

    If (Test-ISEHost)

    {

        # Continue with execution

    }

    Else

    {

       # Exit the code

       Write-Host "This code can only run in the ISE" -ForegroundColor Yellow -BackgroundColor DarkRed

       Break

    }

 

    Write-Host "All Done"

}

This is just an example of making a decision with this code.  Our Test-ISEHost function is now a child function of some other function that we will call Do-Something.  When it is executed in the ISE, it runs to completion.  The message All Done is display.  Copy and paste this into the ConsoleHost and execute it, you will receive the error message on line 18.  Also, the Break statement exits the function and the All Done message is not display because the code stopped executing.

No comments: