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PowerShell Beginner’s Guide
If you are new to PowerShell, this document will walk you through a few examples to give you some basic ideas of PowerShell. We recommend that you open a PowerShell console/session and type along with the instructions in this document to get most out of this exercise.
Launch PowerShell Console/Session
First you need to launch a PowerShell session by following the Installing PowerShell Guide.
Getting Familiar with PowerShell Commands
In this section, you will learn how to
- create a file, delete a file and change file directory
- discover what version of PowerShell you are currently using
- exit a PowerShell session
- get help if you needed
- find syntax of PowerShell cmdlets
- and more
As mentioned above, PowerShell commands are designed to have Verb-Noun structure, for instance Get-Process, Set-Location, Clear-Host, etc. Let’s exercise some of the basic PowerShell commands, also known as cmdlets.
Please note that we will use the PowerShell prompt sign PS /> as it appears on Linux in the following examples. It is shown as PS C:\> on Windows.
1. Get-Process: Gets the processes that are running on the local computer or a remote computer.
By default, you will get data back similar to the following:
PS /> Get-Process
Handles NPM(K) PM(K) WS(K) CPU(s) Id ProcessName
------- ------ ----- ----- ------ -- -----------
- - - 1 0.012 12 bash
- - - 21 20.220 449 powershell
- - - 11 61.630 8620 code
- - - 74 403.150 1209 firefox
…
Only interested in the instance of firefox process that are running on your computer? Try this:
PS /> Get-Process -Name firefox
Handles NPM(K) PM(K) WS(K) CPU(s) Id ProcessName
------- ------ ----- ----- ------ -- -----------
- - - 74 403.150 1209 firefox
Want to get back more than one process? Then just specify process names and separate them with commas.
PS /> Get-Process -Name firefox, powershell
Handles NPM(K) PM(K) WS(K) CPU(s) Id ProcessName
------- ------ ----- ----- ------ -- -----------
- - - 74 403.150 1209 firefox
- - - 21 20.220 449 powershell
2. Clear-Host: Clears the display in the host program.
PS /> Get-Process
PS /> Clear-Host
Type too much just for clearing the screen? Here is how the alias can help.
3. Get-Alias: Gets the aliases for the current session.
PS /> Get-Alias
CommandType Name
----------- ----
…
Alias cd -> Set-Location
Alias cls -> Clear-Host
Alias copy -> Copy-Item
Alias dir -> Get-ChildItem
Alias gc -> Get-Content
Alias gmo -> Get-Module
Alias ri -> Remove-Item
Alias type -> Get-Content
…
As you can see "cls" is an alias of Clear-Host.
Now try it:
PS /> Get-Process
PS /> cls
4. cd - Set-Location: Sets the current working location to a specified location.
PS /> Set-Location /home
PS /home>
5. dir - Get-ChildItem: Gets the items and child items in one or more specified locations.
Get all files under the current directory:
PS /> Get-ChildItem
Get all files under the current directory as well as its subdirectories:
PS /> cd $home
PS /home/jen> dir -Recurse
List all files with "txt" file extension.
PS /> cd $home
PS /home/jen> dir –Path *.txt -Recurse
6. New-Item: Creates a new item.
An empty file is created if you type the following:
PS /home/jen> New-Item -Path ./test.txt
Directory: /home/jen
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 7/7/2016 7:17 PM 0 test.txt
You can use the -Value parameter to add some data to your file. For example, the following command adds the phrase "Hello world!" as a file content to the test.txt. Because the test.txt file exists already, we use -Force parameter to replace the existing content.
PS /home/jen> New-Item -Path ./test.txt -Value "Hello world!" -Force
Directory: /home/jen
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 7/7/2016 7:19 PM 24 test.txt
There are other ways to add some data to a file. For example, you can use Set-Content to set the file contents:
PS /home/jen>Set-Content -Path ./test.txt -Value "Hello world again!"
Or simply use ">" as below:
# create an empty file
"" > test.txt
# set "Hello world!" as content of test.txt file
"Hello world!!!" > test.txt
The pound sign (#) above is used for comments in PowerShell.
7. type - Get-Content: Gets the content of the item at the specified location.
PS /home/jen> Get-Content -Path ./test.txt
PS /home/jen> type -Path ./test.txt
Hello world again!
8. del - Remove-Item: Deletes the specified items.
This cmdlet will delete the file /home/jen/test.txt:
PS /home/jen> Remove-Item ./test.txt
9. $PSVersionTable: Displays the version of PowerShell you are currently using.
Type $PSVersionTable in your PowerShell session, you will see something like below. "PSVersion" indicates the PowerShell version that you are using.
Name Value
---- -----
PSVersion 5.1.10032.0
PSEdition Linux
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 3.0.0.0
CLRVersion
WSManStackVersion 1.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
10. Exit: To exit the PowerShell session, type "exit".
PS /home/jen> exit
Need Help?
The most important command in PowerShell is possibly the Get-Help, which allows you to quickly learn PowerShell without having to search around the internet. The Get-Help cmdlet also shows you how PowerShell commands work with examples.
It shows the syntax and other technical information of the Get-Process cmdlet.
PS /> Get-Help -Name Get-Process
It displays the examples how to use the Get-Process cmdlet.
PS />**Get-Help -Name Get-Process -Examples**
If you use -Full parameter, for example, Get-Help -Name Get-Process -Full, it will display more technical information.
Discover Commands Available on Your System
You want to discover what PowerShell cmdlets available on your system? Just run "Get-Command" as below:
PS /> Get-Command
If you want to know whether a particular cmdlet exists on your system, you can do something like below:
PS /> Get-Command Get-Process
If you want to know the syntax of Get-Process cmdlet, type:
PS /> Get-Command Get-Process -Syntax
If you want to know how to use the Get-Process, type:
PS /> Get-Help Get-Process -Example
PowerShell Pipeline '|'
Sometimes when you run Get-ChildItem or "dir", you want to get a list of files and folders in a descending order. To achieve that, type:
PS /home/jen> dir | sort -Descending
Say you want to get the largest file in a directory
PS /home/jen> dir | Sort-Object -Property Length -Descending | Select-Object -First 1
Directory: /home/jen
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 5/16/2016 1:15 PM 32972 test.log
How to Create and Run PowerShell scripts
- You can use ISE, Visual Studio Code or your favorite editor to create a PowerShell script and save the script with a .ps1 file extension (for example, helloworld.ps1)
- To run the script, cd to your current folder and type ./yourscript.ps1 (for example, ./helloworld.ps1).
Note: If you are using Windows, make sure you set the PowerShell's execution policy to "RemoteSigned" in this case. See [Running PowerShell Scripts Is as Easy as 1-2-3] run-ps for more details.
Recommended Training and Reading
- Video: Get Started with PowerShell from Channel9
- eBooks from PowerShell.org
- eBooks from PowerShell.com
- eBooks List by Martin Schvartzman
- Tutorial from MVP
- Script Guy blog: The best way to Learn PowerShell
- Understanding PowerShell Module
- How and When to Create PowerShell Module by Adam Bertram
- Video: PowerShell Remoting in Depth from Channel9
- PowerShell Basics: Remote Management from ITPro
- Running Remote Commands from PowerShell Web Docs
- Samples for PowerShell Scripts
- Samples for Writing a PowerShell Script Module
- Writing a PowerShell module in C#
- Examples of Cmdlets Code
Commercial Resources
- Windows PowerShell in Action by Bruce Payette
- Windows PowerShell Cookbook by Lee Holmes