PowerShell Notes

Path

Powershell.exe

C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe

Get version

$PSVersionTable.PSVersion

Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.

PS C:\Windows\System32\WindowsPowerShell\v1.0> $PSVersionTable.PSVersion

Major  Minor  Build  Revision
-----  -----  -----  --------
5      1      14393  1198

Example Scripts

Check in C:\Apps\ps for examples!

Notes

• http://ss64.com/ps/syntax-elevate.html
• http://ss64.com/ps/syntax-run.html

• https://blog.netspi.com/15-ways-to-bypass-the-powershell-execution-policy/
• http://www.howtogeek.com/204166/how-to-configure-windows-to-work-with-powershell-scripts-more-easily/

PS C:\Scripts> Start-Process cmd -ArgumentList "/c 1.cmd" -WorkingDirectory c:\test

Blah

    $installerPath = [IO.Path]::Combine($LocalModulePath, 'Install.ps1')
    Write-Host "Installer path: $installerPath"
    if (Test-Path $installerPath) {
        Write-Host 'Install.ps1 exists.  Running Install.ps1'
        & $installerPath
    }

Blah

    Write-Host "Installing module..."
    $eventSource = 'My.Module.Manager'

    try {
        $sourceExists = [System.Diagnostics.EventLog]::SourceExists($eventSource)
    } catch [Security.SecurityException] {
        Write-Verbose "Caught 'SecurityException': $_.Exception.Message" 
    }

    if ($sourceExists) {
        Write-Host "...installation complete..." 
    } else {

        #region ----- Ensure-ProcessIsElevated -----

        if ($Verbose) {
            $VerbosePreference = "Continue"
        }
        if ($Debug) {
            $DebugPreference = "Continue"
        }

        Write-Debug "Command line is ___$($MyInvocation.Line)___"
        Write-Verbose "Entering script body"

        if ($ScriptPath) {
            Set-Location $ScriptPath
            Write-Verbose "Working directory: $pwd"
        }

        If (-Not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")) {
            Write-Warning "This script must be run with elevated privileges."
            Write-Warning "Restarting as an elevated process."
            Write-Warning "You will be prompted for authorization."
            Write-Warning "You may click 'No' and re-run manually, if you prefer."

            If ((Get-WmiObject Win32_OperatingSystem | select BuildNumber).BuildNumber -ge 6000) {
                Write-Verbose "This is a UAC-enabled system. Elevating ..."
                $CommandLine = "$($MyInvocation.Line.Replace($MyInvocation.InvocationName, $MyInvocation.MyCommand.Definition)) -ScriptPath $pwd"
                Write-Verbose "CommandLine: $CommandLine"

                Start-Process -FilePath PowerShell.exe -Verb Runas -ArgumentList "$CommandLine"

            } else {
                Write-Verbose "The system does not support UAC: an elevated process cannot be started."
                Write-Warning "This script requires administrative privileges. Please re-run with administrative account."
            }

            Break
        }

        Write-Verbose "The script is now running with elevated privileges."

        #endregion ----- Ensure-ProcessIsElevated -----

        New-EventLog -LogName Application -Source $eventSource

        Write-Host "...installation complete..."
    }

    Read-Host -Prompt "Press Enter to exit"

Blah

1. https://stackoverflow.com/questions/24546150/how-can-prevent-a-powershell-window-from-closing-so-i-can-see-the-error

Blah

   Write-Output "Backups complete at $(Get-Date -Format u)"
   
   

Blah

    try
    {
        # Do your script's stuff
    }
    catch
    {
        Write-Error $_.Exception.ToString()
        Read-Host -Prompt "The above error occurred. Press Enter to exit."
    }

Blah

    function Log-Message
    {
        [CmdletBinding()]
        Param
        (
            [Parameter(Mandatory=$true, Position=0)]
            [string]$LogMessage
        )

        Write-Output ("{0} - {1}" -f (Get-Date), $LogMessage)
    }

Now you can simple log using:

   Log-Message "Starting Backups"
   Log-Message "Backups Completed"

Output:

   22.07.2016 08:31:15 - Starting Backups
   22.07.2016 08:31:15 - Backups Completed

To Change Directory:

   Set-Location -Path Q:\MyDir

Blah:

   Remove-EventLog -Source 'My.Module.Manager'

https://stackoverflow.com/questions/7834656/create-log-file-in-powershell

Put this at the top of your file:

    $Logfile = "D:\Apps\Logs\$(gc env:computername).log"

    Function LogWrite
    {
       Param ([string]$logstring)

       Add-content $Logfile -value $logstring
    }

Then replace your Write-host calls with LogWrite.

OR:

    Function Write-Log {
        [CmdletBinding()]
        Param(
        [Parameter(Mandatory=$False)]
        [ValidateSet("INFO","WARN","ERROR","FATAL","DEBUG")]
        [String]
        $Level = "INFO",

        [Parameter(Mandatory=$True)]
        [string]
        $Message,

        [Parameter(Mandatory=$False)]
        [string]
        $logfile
        )

        $Stamp = (Get-Date).toString("yyyy/MM/dd HH:mm:ss")
        $Line = "$Stamp $Level $Message"
        If($logfile) {
            Add-Content $logfile -Value $Line
        }
        Else {
            Write-Output $Line
        }
    }

    . .\logger.ps1
    Write-Log "debug message"
    Write-Log "info message" "INFO"

Using this Log-Entry framework:

Script:

    Function Main {
        Log -File "D:\Apps\Logs\$Env:computername.log"

        $tcp = (get-childitem c:\windows\system32\drivers\tcpip.sys).Versioninfo.ProductVersionRaw
        $dfs = (get-childitem C:\Windows\Microsoft.NET\Framework\v2.0.50727\dfsvc.exe).Versioninfo.ProductVersionRaw

        Log "TCPIP.sys Version on $computer is:" $tcp
        Log "DFSVC.exe Version on $computer is:" $dfs

        If (get-wmiobject win32_share | where-object {$_.Name -eq "REMINST"}) {Log "The REMINST share exists on $computer"}
        Else {Log "The REMINST share DOES NOT exist on $computer - Please create as per standards"}

        "KB2450944", "KB3150513", "KB3176935" | ForEach {
            $hotfix = Get-HotFix -Id $_ -ErrorAction SilentlyContinue
            If ($hotfix) {Log -Color Green Hotfix $_ is installed}
            Else {Log -Color Red Hotfix $_ " is NOT installed - Please ensure you install this hotfix"}
        }
    }