Cheat Sheet

PowerShell pipes objects, not text. Get-Process | Where-Object CPU -gt 10 filters on a property; there is no column parsing as with grep and awk:

Get-Process | Where-Object CPU -gt 10 | Sort-Object CPU -Descending | Select-Object -First 5 Name, CPU

Basics

$folder = 'C:\Program Files\Microsoft Office\Office16\'   # single quotes: literal
Write-Host "Folder: $folder"                              # double quotes expand variables

$letters = "a", "b", "c"
foreach ($letter in $letters) {
    Write-Host $letter
}

if ($a -gt 2) {
    Write-Host "$a is greater than 2"
} elseif ($a -eq 2) {
    Write-Host "$a is 2"
} else {
    Write-Host "$a is less than 2 or not set"
}

function Get-Greeting([string]$Name = "World") {
    "Hello $Name"   # values that aren't captured are returned
}
Get-Greeting -Name Ada

Comparison operators

> and < are redirections in PowerShell, so comparisons use named operators. They are case-insensitive; prefix them with c (-ceq) for case-sensitive comparison.

Operator	Meaning	Example
`-eq`, `-ne`	equal, not equal	`$name -eq "admin"`
`-gt`, `-ge`	greater (or equal)	`$size -gt 1GB`
`-lt`, `-le`	less (or equal)	`$count -lt 10`
`-like`	wildcard match	`$file -like "*.log"`
`-match`	regex match, sets `$Matches`	`$line -match "error (\d+)"`
`-contains`, `-in`	collection membership	`$list -contains "x"`, `"x" -in $list`
`-and`, `-or`, `-not`	logic	`($a -gt 1) -and -not $b`

Useful commands

Command	Effect
`Get-Help <cmdlet> -Examples`	Usage examples of a cmdlet.
`Get-Command service`	Finds cmdlets by name.
`Get-Process \| Get-Member`	The properties and methods of the objects.
`"Test" \| Out-File ./Test.txt`	Writes to a file (`-Append` to append).
`Select-String -Path .\*.txt -Pattern 'Get-'`	Searches files, like `grep`.
`Get-ChildItem -Recurse -Filter *.log`	Finds files recursively.
`Get-AppxPackage -Name $app -AllUsers \| Remove-AppxPackage -AllUsers`	Removes a Store app for all users.
`New-Item -Path "HKLM:\Software\Policies\Microsoft\Windows"`	Creates a registry key.
`New-ItemProperty -Path "HKLM:\Software\Policies\Microsoft\Windows" -Name 'NoGenTicket' -Value 1 -PropertyType DWord`	Creates a registry value.