A very simple PowerShell script to keep a Windows PC awake and make lync think the user is active on the keyboard

keepawake.ps1

# Useful references:
#
# https://superuser.com/questions/992511/emulate-a-keyboard-button-via-the-command-line
# https://ss64.com/vb/sendkeys.html
# https://social.technet.microsoft.com/Forums/windowsserver/en-US/96b339e2-e9da-4802-a66d-be619aeb21ac/execute-function-one-time-in-every-10-mins-in-windows-powershell?forum=winserverpowershell
# https://learn-powershell.net/2013/02/08/powershell-and-events-object-events/
#
# Future enhancements - use events rather than an infinite loop
$wsh = New-Object -ComObject WScript.Shell
while (1) {
  # Send Shift+F15 - this is the least intrusive key combination I can think of and is also used as default by:
  # http://www.zhornsoftware.co.uk/caffeine/
  # Unfortunately the above triggers a malware alert on Sophos so I needed to find a native solution - hence this script...
  $wsh.SendKeys('+{F15}')
  Start-Sleep -seconds 59
}

In general, the script runs beautiful. I had reduced it to the following oneliner, which even adds a random element:

$wsh=New-Object -ComObject WScript.Shell;$i=0;while(1) {$wsh.SendKeys('+{F15}');clear;write-host 'Caffeine applied for' $i seconds -nonewline;$j=(Get-Random -Minimum 5 -Maximum 25);$i=$i+$j;sleep $j}

The only problem is: It only doesn't run any more with PowerShell in ConstraintLanguage Mode, it appears this disables the function SendKeys. Does anyone have an alternate how to provide the function while ConstraintLanguage Mode is active?

my example from 2 years ago doesn't use powershell at all, but it's a standalone file.

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Thanks for sharing this lightweight PowerShell approach using WScript.Shell SendKeys. Using key combinations like {F15} or {NUMLOCK} is a smart way to prevent sleep states without disrupting active typing. We often look into similar automation tricks and tech setups while planning modern display and media setups at Media Walls Ideas. Native scripts like this save a lot of time compared to installing third-party apps!