powershell script does not run properly from a batch file

Question

I have a functioning PowerShell script which registers a timer object and sends a key every couple of minutes.

$wshell = New-Object -ComObject Wscript.Shell    

...

function fctName {
    param([ScriptBlock] $action)

    ...

    Register-ObjectEvent -InputObject $timer -EventName Elapsed -SourceIdentifier Timer.Elapsed -Action $action
}

fctName {

    ...

    $wshell.sendkeys("{ESC}")
}

Within the Windows PowerShell ISE the script works just fine, without any errors. But, I would love to run it from a batch file, in which I wrote only this line:

Powershell.exe -noexit C:\...\ScriptName.ps1

No errors are thrown but it does not do what I want, which is to prevent Windows going idle.

Because I '-noexit' the cmd window, I can easily stop the event with

Unregister-Event -SourceIdentifier Timer.Elapsed

It seems to be working because only typing it twice throws an error.

Could it be that my batch file needs different code? Maybe "echo" etc. I'm not very familiar with it
Could it be that I have to import a module in Powershell?

I think the problem is that scheduled tasks living in a different session/context respect to the one of the logged user. SendKeys aren't send in the actual user session. — CB.
– CB., Commented Apr 10, 2013 at 14:44

rojo · Accepted Answer · 2013-04-10 15:14:21Z

1

I'm not that comfortable with PowerShell, but in JScript you could use this code:

var osh = new ActiveXObject("WScript.Shell")
WSH.Echo(
    /cscript/i.test(WSH.FullName)
    ? 'Anti-idle running. Hit Ctrl-C to exit'
    : "Anti-idle running.\nTo stop, use task manager to kill wscript.exe"
);
while (1) {
    WSH.Sleep(120 * 1000);
    osh.SendKeys("{SCROLLLOCK}{SCROLLLOCK}");
}

Save that with a .js extension and you can double-click it to launch it, or launch it from a cmd console via cscript /nologo scriptfile.js.

I think toggling Scroll Lock is more benign than sending Esc, as Esc could have unwanted consequences depending on what application happens to have focus when the SendKeys line fires.

Does PowerShell have access to Windows Script Host methods like Sleep? Apparently so with Start-Sleep. That might be preferable to spawning a timer. Hopefully if my JScript code isn't suitable natively for your evil purposes, it will at least be suitable as pseudocode for your PowerShell script.

edited Apr 10, 2013 at 15:14

answered Apr 10, 2013 at 14:56

rojo

24.5k5 gold badges61 silver badges104 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

nivoe Over a year ago

True story. Works only with SendKeys, such as [System.Windows.Forms.SendKeys]::SendWait("{SCROLLLOCK}{SCROLLLOCK}") and the Start-Sleep function in PowerShell within a loop.

Collectives™ on Stack Overflow

powershell script does not run properly from a batch file

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related