problem of comparating 2 boot times.

PowerShell Help
1

Hello,

I’ve a problem with my code, i’m not very specialist of PS, and i think that my problem is from a variable problem.

I try to compile a PS script that do some tricks if a PC was booted since less than X minutes, and other things if > 7 minutes

That’s my code:

function get-uptime {
  [int]$reftime=7
  $os = Get-WmiObject win32_operatingsystem
  $time = (Get-Date) - ($os.ConvertToDateTime($os.lastbootuptime))
  $display = "time since last boot: " + $time.Days + " days, " + $time.Hours + " hours, " + $time.Minutes + " minutes and " + $time.Seconds + " seconds"
  Write-Output $display
  [int]$BootMinutes= $time.TotalMinutes
  $display2 = "Computer boot since " + $BootMinutes + " Minutes"
  $display2
  Write-output $BootMinutes
  Write-Output $time.TotalMinutes
  Write-Output $reftime
}

get-uptime

    If ($BootMinutes -lt $reftime) {
        Write-Host "less than 7 min since last boot"
}
    If ($BootMinutes -ge $reftime) {

    Write-host "more than 7 min since last boot"
  }

I try with 13 minutes and it’s ok:

“Computer boot since 13 Minutes
13
13,4964267466667
7
more than 7 min since last boot”

I try now with 5 minutes, and i don’t knows why, but it doesn’t work:

“Computer boot since 5 Minutes
5
4,81610453666667
7
more than 7 min since last boot”

Anybody have an idea what i’m wrong?

Thank you for your help

2

May I suggest a different approach?

function Get-Uptime {
    $BootTime = (Get-CimInstance -ClassName CIM_OperatingSystem).LastBootUpTime
    $Now = Get-Date
    $Uptime = New-TimeSpan -Start $BootTime -End $Now
    [PSCustomObject]@{
        BootTime = $BootTime
        UpTime    = $Uptime
        Message   = "This computer is up for {0} days, {1} hours, {2} minutes and {3} seconds." -f $Uptime.Days, $Uptime.Hours, $Uptime.Minutes, $Uptime.Seconds
    }
}

$SevenMinutesAgo = (Get-Date).AddMinutes(-7)

If ((Get-Uptime).BootTime -gt $SevenMinutesAgo) {
    Write-Host "less than 7 min since last boot"
}
If ((Get-Uptime).BootTime -lt $SevenMinutesAgo) {
    Write-host "more than 7 min since last boot"
}
3

How are you planning on executing this script? Understand that you would basically have to run that script on boot and loop continually to see where the to hit the 7 min mark. If you are launching it at boot, why not just do basic sleeps:

#Wait 5 min...
Start-Sleep -Seconds (5 * 60)

'Starting tricks...'

#Wait 2 min...
Start-Sleep -Seconds (2 * 60)

'Starting more tickets...'
4

Hi olaf,

 

Ok, it’s sure, it works with your script! and i will use it to continue my script.

But, if i want to progress, i want to undestand why my script is bad!

Thank you.

 

 

5

Hello rob,

 

No it’s the beginning of a script, and i think that it is not the good way, but i’m not good in PS, so i must start with something.

The idea is that : We will open all computer of our company on a date/hour (for example, sunday) with a bios auto boot config.

The idea is to lunch, somes minutes after the boot (5 minutes i think), a script that will analyse if the computer is open since 7 minutes.

The idea is:

 

  • If computer is booted more than 7 minutes : there is a chance that this is a pc that is using by a users : so DO NOTHING
  • If computer is booted less thant 7 minutes : the pc just booted up, so we do some tricks (update, antivirus, cleaning script, and finally, shutdown).
 
6

I have a dump question.

Message = “This computer is up for {0} days, {1} hours, {2} minutes and {3} seconds.” -f $Uptime.Days, $Uptime.Hours, $Uptime.Minutes, $Uptime.Seconds

What is “-f” for ? Any reference that I can look at

7

It is formating the strings using placeholders, and please refer to this link below…

https://ss64.com/ps/syntax-f-operator.html

8

Thanks a lot.