Getting Started

All of Powershell's commands follow a Verb-Object pattern.

Powershell is object-oriented, thus every object has methods and properties.

Powershell allows the use of aliases i.e. Get-ChildItem is the same as dir or ls. See Common Commands for more.

Common Commands

Manage Processes

Start-Process; Stop-Process

Manage Services

Start-Service; Stop-Service

Manage/Navigate File System

New-Item; Move-Item; Remove-Item; Copy-Item

Get-ChildItem

Set-Location

Write-Host; Read-Host

Use the "Help"

Powershell has a great built-in help system which is incredibly useful for gaining info on commands or Powershell properties. Look at the below command:

Get-Help Start-Process

This will bring up some basic information about the command such as Syntax, Description, and Related Links, BUT it can do so much more. You can control how much detail the "Help" system gives you by using certain switches such as "-Detailed", "-Full", and "-Examples". I recommend the "-ShowWindow" switch which will give you all the available details in a separate window, which is great for keeping the console window clean:

Get-Help Start-Process -ShowWindow

"Help" can also be used to search for commands or modules of interest and it accepts wildcards.

"Get-Help *process*" will bring all commands that have "process" anywhere in the name. Additionally you can use only one asterisk, "*process" or "process*", if you want to search for commands that have "process" in either the front or the back.

Variables

Powershell will let you save and use variables inside both scripts and console windows. 

$Var = ...

This function makes invoking methods much simpler. Here's a common one:

$Bitness = Get-wmiobject win32_operatingsystem

$Bitness.OSarchitecture

The former line grabs the OS object and stores it into the variable. This means one can use the variable to invoke all the methods and properties assigned to the object.

It takes two lines but is easier to use and read than the alternative:

(Get-wmiobject win32_operatingsystem).OSarchitecture

The latter would require entering the entire line to access the property. If you only need the one property then

$Bitness = (Get-wmiobject win32_operatingsystem).OSarchitecture

is better to use as it stores the string found in "OSarchitecture" instead of storing the whole object.

Environment Variables

Much like, Command Line, Powershell uses Environment Variables but in a slightly different way. Environment Variables look like variables in structure, $env:SystemRoot, but use a colon.

Get-ChildItem env:

Use the above line to view the current Environment Variables.

Pipeline

Most of Powershell's commands have an output which can be transferred directly to another command. Below is a simple example.

Get-Process | Out-Gridview

Using the pipeline can produce several different results, but allow you to customize the output according to your needs.

Get-Process | sort -Property Name,ID | export-csv -Path "$env:userprofile\Desktop\processes.csv"

The above line grabs all processes, sorts them by Name then ID and finally exports them to the Desktop as a csv file. The "$env:userprofile" is an environment variable. View Environment Variables to learn more.

Scripting

Execution Policy

The Execution Policy is a safety feature which prevents scripts from running on the machine. The default policy on all new Windows OS's is Restricted which prevents all scripts from running on the machine. 

Set-ExecutionPolicy -ExecutionPolicy Bypass 

The above line allows all scripts to run but it alters the settings for the entire machine. You can specify how far the policy is implemented.

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope CurrentUser will allow scripts to run for the user.

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process will allow scripts to run for the current Powershell session and will not affect current policy settings.