Some Windows PowerShell tricks

Here are some PowerShell tricks that works on Windows.

Add a path to System PATH environment variable.

function AddToPath {
    param (
        [string]$folder
    )

    Write-Host "Adding $folder to environment variables..." -ForegroundColor Yellow

    $currentEnv = [Environment]::GetEnvironmentVariable("Path", [EnvironmentVariableTarget]::Machine).Trim(";");
    $addedEnv = $currentEnv + ";$folder"
    $trimmedEnv = (($addedEnv.Split(';') | Select-Object -Unique) -join ";").Trim(";")
    [Environment]::SetEnvironmentVariable(
        "Path",
        $trimmedEnv,
        [EnvironmentVariableTarget]::Machine)

    $env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User")
}

Get if is elevated (Administrator)

    $id = [System.Security.Principal.WindowsIdentity]::GetCurrent()
    $p = New-Object System.Security.Principal.WindowsPrincipal($id)
    if ($p.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator))
    { Write-Output $true }      
    else
    { Write-Output $false }  

Clean up useless nvironment variable 'PATH'

function Update-PathVariable {
    param (
        [string]$variableScope = "Machine",
        [switch]$verbose
    )

    # Get the current PATH environment variable
    $currentPath = [Environment]::GetEnvironmentVariable("PATH", $variableScope)

    # Split the PATH string into an array of directories
    $directories = $currentPath -split ';'

    # Initialize an empty array to store updated directories
    $updatedDirectories = @()

    foreach ($directory in $directories) {
        # Check if the directory exists
        if (Test-Path -Path $directory -PathType Container) {
            # If the directory exists, add it to the updated directories array
            $updatedDirectories += $directory
        } elseif ($verbose) {
            # If the directory doesn't exist and verbose output is enabled, print the directory to be removed
            Write-Host "Removing non-existent directory from PATH: $directory"
        }
    }

    # Join the updated directories back into a single PATH string
    $newPath = $updatedDirectories -join ';'

    # Check if the new PATH value is different from the original value
    if ($newPath -eq $currentPath) {
        if ($verbose) {
            Write-Host "No changes needed to the $variableScope PATH variable."
        }
        return
    }

    try {
        # Set the new PATH environment variable
        [Environment]::SetEnvironmentVariable("PATH", $newPath, $variableScope)

        if ($verbose) {
            # Print the updated PATH variable
            Write-Host "Updated $variableScope PATH: $($newPath)"
        }

        # Update the current session's PATH environment variable
        $env:Path = [System.Environment]::GetEnvironmentVariable("Path", "Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path", "User")
    } catch {
        Write-Host "Error: Failed to update the $variableScope PATH variable. Please ensure you have the necessary permissions."
    }
}

# Call the Update-PathVariable function
Update-PathVariable -variableScope "Machine" -verbose

Find current wallpaper (In slides mode)

$bytes=(New-Object -ComObject WScript.Shell).RegRead("HKEY_CURRENT_USER\Control Panel\Desktop\TranscodedImageCache")
$wallpaperpath=[System.Text.Encoding]::Unicode.GetString($bytes[24..($bytes.length-1)])
$wallpaperpath=$wallpaperpath.substring(0, $wallpaperpath.IndexOf("jpg", 0, $wallpaperpath.Length)+3)
Write-Host $wallpaperpath

Set wallpaper to a file

function Set-WallPaper($Image) {
    Add-Type -TypeDefinition @" 
    using System; 
    using System.Runtime.InteropServices;

    public class Params
    { 
        [DllImport("User32.dll",CharSet=CharSet.Unicode)] 
        public static extern int SystemParametersInfo (Int32 uAction, 
                                                       Int32 uParam, 
                                                       String lpvParam, 
                                                       Int32 fuWinIni);
    }
"@ 
    $SPI_SETDESKWALLPAPER = 0x0014
    $UpdateIniFile = 0x01
    $SendChangeEvent = 0x02
    $fWinIni = $UpdateIniFile -bor $SendChangeEvent
    $ret = [Params]::SystemParametersInfo($SPI_SETDESKWALLPAPER, 0, $Image, $fWinIni)
}

Trigger Store to upgrade all apps

$namespaceName = "root\cimv2\mdm\dmmap"
$className = "MDM_EnterpriseModernAppManagement_AppManagement01"
$wmiObj = Get-WmiObject -Namespace $namespaceName -Class $className
$wmiObj.UpdateScanMethod() | Format-Table -AutoSize

Pin a path to quick access

Write-Host "Pin repos to quick access..." -ForegroundColor Green
$load_com = new-object -com shell.application
$load_com.Namespace("$env:USERPROFILE\source\repos").Self.InvokeVerb("pintohome")
$load_com.Namespace("\\VAULT\").Self.InvokeVerb("pintohome")

Recursively searches for items in the user's home directory that start with "." and sets them as hidden.

Write-Host "Set home path hidden folders and files..." -ForegroundColor Green
Get-ChildItem -Path $HOME -Filter .* -Recurse -Force -ErrorAction SilentlyContinue | ForEach-Object { $_.Attributes = $_.Attributes -bor [System.IO.FileAttributes]::Hidden }