Be aware of this PowerShell/AutoHotkey gotcha

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I tend to do most of my automation using AutoHotkey, for example to automate tweaks to new installs of Windows. Windows 10 has made things more difficult (deliberate obfuscation, in my opinion) so there are times when only PowerShell can be used, for example to automate the uninstallation of Windows 10s built-in apps.

Whilst I was testing an AutoHotkey script that tweaks a new install of Windows 10 I discovered a gotcha which had me beaten for a while. The following will demonstrate what I ran into.

Screenshot of AHK script calling PowerShell with successful result:
44938-ps_gotcha1
Click to enlarge

Screenshot of amended AHK script showing reproducible error about a missing curly brace. (It’s not missing!)
44939-ps_gotcha2
Click to enlarge

The only difference is that I added a comment to the end of the PowerShell section.

Note that error cannot be reproduced in the PowerShell ISE or just running a PowerShell (.PS1) script instead.

Hope this helps if anyone else uses AutoHotkey with Powershell…

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Rick,

I don’t have AutoHotKey but out of curiosity give this a try.

psScript =
(
{
Your code lines here
}
)

That will turn the code & comments into a Script Block which PS may interpret differently.

HTH :cheers:

May the Forces of good computing be with you!

RG

PowerShell & VBA Rule!
Computer Specs

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Hi RG… I’ve just tried that. The error doesn’t appear, only the comment line, i.e. the command itself doesn’t execute.

44940-ps_gotcha3
Click to enlarge

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Rick,

Removing the ampersand as well as the braces produces the expected result.

i.e. Instead of Run powershell.exe -NoExit -Command & {%psScript%}
change it to Run powershell.exe -NoExit -Command %psScript%

HTH

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Hi Cliff,

Hmmm, you’re right. Thank you. And it works even when there’s a comment after the PS commandline, provided I don’t try to change the PS code into a code block.

This works:

Code:

psScript =
(
    Get-HotFix | Select HotFixID,InstalledOn,InstalledBy -First 1
    # This is a comment
)

; Use this call if you don’t want to see PowerShell output
;RunWait PowerShell.exe -Command &{%psScript%} ,, hide

; Use this call if you want to see PowerShell output
Run powershell.exe -NoExit -Command %psScript%

This doesn’t work:

Code:

psScript =
(
{
    Get-HotFix | Select HotFixID,InstalledOn,InstalledBy -First 1
    # This is a comment
}
)

; Use this call if you don’t want to see PowerShell output
;RunWait PowerShell.exe -Command &{%psScript%} ,, hide

; Use this call if you want to see PowerShell output
Run powershell.exe -NoExit -Command %psScript%

I also noticed that PowerShell 5 (Windows 10) adds a comment to the top of the results re: “Cannot load PSReadline module. Console is running without PSReadline.” This hasn’t happened with PowerShell 2 (Win 7).

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Rick,

If this is a new installation of Win10, check the ExecutionPolicy setting. It is probably set to Restricted or AllSigned. If so, change it to something a bit less restrictive.

Regards

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I’ve found this to be a simple way to insure you can execute the script:

Code:

Runwait powershell.exe Set-ExecutionPolicy Unrestricted
Runwait powershell.exe yourscript.ps1
Runwait powershell.exe Set-ExecutionPolicy Restricted

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