PowerShell Cheat Sheet ====================== Basic Commands -------------- ``` Cmdlet : Commands built into shell written in .NET Functions : Commands written in PowerShell language Parameter : Argument to a Cmdlet/Function/Script Alias : Shortcut for a Cmdlet or Function Scripts : Text files with .ps1 extension Applications : Existing windows programs Pipelines : Pass objects Get-process word | Stop-Process Ctrl+c : Interrupt current command Left/right : Navigate editing cursor Ctrl+left/right : Navigate a word at a time Home / End : End Move to start / end of line Up / down : Move up and down through history Insert : Toggles between insert/overwrite mode F7 : Command history in a window Tab / Shift-Tab : Command line completion ``` Commands to get Help -------------------- ``` Get-Command # Retrieves a list of all the commands available to PowerShell # (native binaries in $env:PATH + cmdlets / functions from PowerShell modules) Get-Command -Module Microsoft* # Retrieves a list of all the PowerShell commands exported from modules named Microsoft* Get-Command -Name *item # Retrieves a list of all commands (native binaries + PowerShell commands) ending in "item" Get-Help # Get all help topics Get-Help -Name about_Variables # Get help for a specific about_* topic (aka. man page) Get-Help -Name Get-Command # Get help for a specific PowerShell function Get-Help -Name Get-Command -Parameter Module # Get help for a specific parameter on a specific command ``` Variables --------- ``` $a = 0 # Initialize a variable [int]$a = 'Paris' # Initialize a variable, with the specified type (throws an exception) [string]$a = 'Paris' # Initialize a variable, with the specified type (doesn't throw an exception) $a,$b = 0 or $a,$b = 'a','b' # Assign multiple variables $a,$b = $b,$a # Flip variables $var=[int]5 # Strongly typed variable Get-Command -Name *varia* # Get a list of commands related to variable management Get-Variable # Get an array of objects, representing the variables in the current and parent scopes Get-Variable | ? { $PSItem.Options -contains 'constant' } # Get variables with the "Constant" option set Get-Variable | ? { $PSItem.Options -contains 'readonly' } # Get variables with the "ReadOnly" option set New-Variable -Name FirstName -Value Trevor New-Variable FirstName -Value Trevor -Option Constant # Create a constant variable, that can only be removed by restarting PowerShell New-Variable FirstName -Value Trevor -Option ReadOnly # Create a variable that can only be removed by specifying the -Force parameter on Remove-Variable Remove-Variable -Name firstname # Remove a variable, with the specified name Remove-Variable -Name firstname -Force # Remove a variable, with the specified name, that has the "ReadOnly" option set ``` Operators --------- ``` $a = 2 # Basic variable assignment operator $a += 1 # Incremental assignment operator $a -= 1 # Decrement assignment operator $a -eq 0 # Equality comparison operator $a -ne 5 # Not-equal comparison operator $a -gt 2 # Greater than comparison operator $a -lt 3 # Less than comparison operator $FirstName = 'Trevor' $FirstName -like 'T*' # Perform string comparison using the -like operator, which supports the wildcard (*) character. Returns $true $BaconIsYummy = $true $FoodToEat = $BaconIsYummy ? 'bacon' : 'beets' # Sets the $FoodToEat variable to 'bacon' using the ternary operator 'Celery' -in @('Bacon', 'Sausage', 'Steak', 'Chicken') # Returns boolean value indicating if left-hand operand exists in right-hand array 'Celery' -notin @('Bacon', 'Sausage', 'Steak') # Returns $true, because Celery is not part of the right-hand list 5 -is [string] # Is the number 5 a string value? No. Returns $false. 5 -is [int32] # Is the number 5 a 32-bit integer? Yes. Returns $true. 5 -is [int64] # Is the number 5 a 64-bit integer? No. Returns $false. 'Trevor' -is [int64] # Is 'Trevor' a 64-bit integer? No. Returns $false. 'Trevor' -isnot [string] # Is 'Trevor' NOT a string? No. Returns $false. 'Trevor' -is [string] # Is 'Trevor' a string? Yes. Returns $true. $true -is [bool] # Is $true a boolean value? Yes. Returns $true. $false -is [bool] # Is $false a boolean value? Yes. Returns $true. 5 -is [bool] # Is the number 5 a boolean value? No. Returns $false. ``` Flow Control ------------ ``` if (1 -eq 1) { } # Do something if 1 is equal to 1 do { 'hi' } while ($false) # Loop while a condition is true (always executes at least once) while ($false) { 'hi' } # While loops are not guaranteed to run at least once while ($true) { } # Do something indefinitely while ($true) { if (1 -eq 1) { break } } # Break out of an infinite while loop conditionally for ($i = 0; $i -le 10; $i++) { Write-Host $i } # Iterate using a for..loop foreach ($item in (Get-Process)) { } # Iterate over items in an array switch ('test') { 'test' { 'matched'; break } } # Use the switch statement to perform actions based on conditions. Returns string 'matched' switch -regex (@('Trevor', 'Daniel', 'Bobby')) { # Use the switch statement with regular expressions to match inputs 'o' { $PSItem; break } # NOTE: $PSItem or $_ refers to the "current" item being matched in the array } switch -regex (@('Trevor', 'Daniel', 'Bobby')) { # Switch statement omitting the break statement. Inputs can be matched multiple times, in this scenario. 'e' { $PSItem } 'r' { $PSItem } } ``` Functions --------- ``` function add ($a, $b) { $a + $b } # A basic PowerShell function function Do-Something { # A PowerShell Advanced Function, with all three blocks declared: BEGIN, PROCESS, END [CmdletBinding]()] param () begin { } process { } end { } } ``` Regular Expressions ------------------- ``` 'Trevor' -match '^T\w*' # Perform a regular expression match against a string value. # Returns $true and populates $matches variable $matches[0] # Returns 'Trevor', based on the above match @('Trevor', 'Billy', 'Bobby') -match '^B' # Perform a regular expression match against an array of string values. Returns Billy, Bobby $regex = [regex]'(\w{3,8})' $regex.Matches('Trevor Bobby Dillon Joe Jacob').Value # Find multiple matches against a singleton string value. ``` Working with Modules -------------------- ``` Get-Command -Name *module* -Module mic*core # Which commands can I use to work with modules? Get-Module -ListAvailable # Show me all of the modules installed on my system (controlled by $env:PSModulePath) Get-Module # Show me all of the modules imported into the current session $PSModuleAutoLoadingPreference = 0 # Disable auto-loading of installed PowerShell modules, when a command is invoked Import-Module -Name NameIT # Explicitly import a module, from the specified filesystem path or name (must be present in $env:PSModulePath) Remove-Module -Name NameIT # Remove a module from the scope of the current PowerShell session New-ModuleManifest # Helper function to create a new module manifest. You can create it by hand instead. New-Module -Name trevor -ScriptBlock { # Create an in-memory PowerShell module (advanced users) function Add($a,$b) { $a + $b } } New-Module -Name trevor -ScriptBlock { # Create an in-memory PowerShell module, and make it visible to Get-Module (advanced users) function Add($a,$b) { $a + $b } } | Import-Module ``` Module Management ----------------- ``` Get-Command -Module PowerShellGet # Explore commands to manage PowerShell modules Find-Module -Tag cloud # Find modules in the PowerShell Gallery with a "cloud" tag Find-Module -Name ps* # Find modules in the PowerShell Gallery whose name starts with "PS" Install-Module -Name NameIT -Scope CurrentUser -Force # Install a module to your personal directory (non-admin) Install-Module -Name NameIT -Force # Install a module to your personal directory (admin / root) Install-Module -Name NameIT -RequiredVersion 1.9.0 # Install a specific version of a module Uninstall-Module -Name NameIT # Uninstall module called "NameIT", only if it was installed via Install-Module Register-PSRepository -Name -SourceLocation # Configure a private PowerShell module registry Unregister-PSRepository -Name # Deregister a PowerShell Repository ``` Filesystem ---------- ``` New-Item -Path c:\test -ItemType Directory # Create a directory mkdir c:\test2 # Create a directory (short-hand) New-Item -Path c:\test\myrecipes.txt # Create an empty file Set-Content -Path c:\test.txt -Value '' # Create an empty file [System.IO.File]::WriteAllText('testing.txt', '') # Create an empty file using .NET Base Class Library Remove-Item -Path testing.txt # Delete a file [System.IO.File]::Delete('testing.txt') # Delete a file using .NET Base Class Library ``` Hashtables (Dictionary) ----------------------- ``` $Person = @{ FirstName = 'Markus' LastName = 'Fleschutz' Likes = @( 'Bacon', 'Beer' ) } # Create a PowerShell HashTable $Person.FirstName # Retrieve an item from a HashTable $Person.Likes[-1] # Returns the last item in the "Likes" array, in the $Person HashTable (software) $Person.Age = 50 # Add a new property to a HashTable ``` Windows Management Instrumentation (WMI) (Windows only) ------------------------------------------------------- ``` Get-CimInstance -ClassName Win32_BIOS # Retrieve BIOS information Get-CimInstance -ClassName Win32_DiskDrive # Retrieve information about locally connected physical disk devices Get-CimInstance -ClassName Win32_PhysicalMemory # Retrieve information about install physical memory (RAM) Get-CimInstance -ClassName Win32_NetworkAdapter # Retrieve information about installed network adapters (physical + virtual) Get-CimInstance -ClassName Win32_VideoController # Retrieve information about installed graphics / video card (GPU) Get-CimClass -Namespace root\cimv2 # Explore the various WMI classes available in the root\cimv2 namespace Get-CimInstance -Namespace root -ClassName __NAMESPACE # Explore the child WMI namespaces underneath the root\cimv2 namespace ``` Asynchronous Event Registration ------------------------------- ``` #### Register for filesystem events $Watcher = [System.IO.FileSystemWatcher]::new('c:\tmp') Register-ObjectEvent -InputObject $Watcher -EventName Created -Action { Write-Host -Object 'New file created!!!' } #### Perform a task on a timer (ie. every 5000 milliseconds) $Timer = [System.Timers.Timer]::new(5000) Register-ObjectEvent -InputObject $Timer -EventName Elapsed -Action { Write-Host -ForegroundColor Blue -Object 'Timer elapsed! Doing some work.' } $Timer.Start() ``` PowerShell Drives (PSDrives) ---------------------------- ``` Get-PSDrive # List all the PSDrives on the system New-PSDrive -Name videos -PSProvider Filesystem -Root x:\data\content\videos # Create a new PSDrive that points to a filesystem location New-PSDrive -Name h -PSProvider FileSystem -Root '\\storage\h$\data' -Persist # Create a persistent mount on a drive letter, visible in Windows Explorer Set-Location -Path videos: # Switch into PSDrive context Remove-PSDrive -Name xyz # Delete a PSDrive ``` Data Management --------------- ``` Get-Process | Group-Object -Property Name # Group objects by property name Get-Process | Sort-Object -Property Id # Sort objects by a given property name Get-Process | Where-Object -FilterScript { $PSItem.Name -match '^c' } # Filter objects based on a property matching a value gps | where Name -match '^c' # Abbreviated form of the previous statement ``` PowerShell Classes ------------------ ``` class Person { [string] $FirstName # Define a class property as a string [string] $LastName = 'Sullivan' # Define a class property with a default value [int] $Age # Define a class property as an integer Person() { # Add a default constructor (no input parameters) for a class } Person([string] $FirstName) { # Define a class constructor with a single string parameter $this.FirstName = $FirstName } [string] FullName() { return '{0} {1}' -f $this.FirstName, $this.LastName } } $Person01 = [Person]::new() # Instantiate a new Person object. $Person01.FirstName = 'Trevor' # Set the FirstName property on the Person object. $Person01.FullName() # Call the FullName() method on the Person object. Returns 'Trevor Sullivan' class Server { # Define a "Server" class, to manage remote servers. Customize this based on your needs. [string] $Name [System.Net.IPAddress] $IPAddress # Define a class property as an IPaddress object [string] $SSHKey = "$HOME/.ssh/id_rsa" # Set the path to the private key used to authenticate to the server [string] $Username # Set the username to login to the remote server with RunCommand([string] $Command) { # Define a method to call a command on the remote server, via SSH ssh -i $this.SSHKey $this.Username@$this.Name $this.Command } } $Server01 = [Server]::new() # Instantiate the Server class as a new object $Server01.Name = 'webserver01.local' # Set the "name" of the remote server $Server01.Username = 'root' # Set the username property of the "Server" object $Server01.RunCommand("hostname") # Run a command on the remote server ``` REST APIs --------- ``` $Params = @{ Uri = 'https://api.github.com/events' Method = 'Get' } Invoke-RestMethod @Params # Call a REST API, using the HTTP GET method ```