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PowerShell Beginners 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
As mentioned above PowerShell commands is 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 /> in the following examples as it shows on Linux. It looks like PS C:> on Windows.
1. Get-Process: displays the processes running on your system.
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, separating with commas. For example,
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 command window
PS /> Get-Process
PS /> Clear-Host
Type too much just for clearing the screen? Here is how the alias can help.
3. Get-Alias: Improves the user experience by using the Cmdlet aliases
To find the available aliases, you can type below cmdlet:
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: change your current working directory
PS /> Set-Location /home
PS /home>
5. ls or dir - Get-ChildItem: list all items in the specified location
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 file extension "txt".
PS /> cd $home
PS /home/jen> dir –Path *.txt -Recurse
6. New-Item: Create a file
An empty file is created if you type the following:
PS /home/jen> New-Item -Path ./test.ps1
Directory: /home/jen
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 7/7/2016 7:17 PM 0 test.ps1
You can use the -value parameter to add some data to your file. For example, the following command adds the phrase "Write-Host 'Hello There'" as a file content to the test.ps1. Because the test.txt file exists already, we use -force parameter to replace the existing content.
PS /home/jen> New-Item -Path ./test.ps1 -Value "Write-Host 'hello there'" -force
Directory: /home/jen
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 7/7/2016 7:19 PM 24 test.ps1
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.ps1 -Value "Write-Host 'hello there again!'"
Or simply use ">" as below:
# create an empty file
"" > empty.txt
# set "hello world!!!" as content of text.txt file
"hello world!!!" > empty.txt
The pound sign (#) above is used for comments in PowerShell.
7. type - Get-Content: get the content of an item
PS /home/jen> Get-Content -Path ./test.ps1
PS /home/jen> type -Path ./test.ps1
"Write-Host 'hello there again!'"
8. del - Remove-Item: delete a file or folder
This cmdlet will delete the file /home/jen/test.ps1:
PS /home/jen> Remove-Item ./test.ps1
9. 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 surfing around the Internet. The Get-Help cmdlet also shows you how PowerShell commands work with examples.
PS />Get-Help
You can use this cmdlet to get help with any PowerShell commands.
PS />Get-Help -Name Get-Process
It shows the syntax and other technical information of the Get-Process cmdlet.
PS />Get-Help -Name Get-Process -Examples
It displays the examples how to use the Get-Process cmdlet. If you use -full parameter, i.e., "Get-Help -Name Get-Process -Full", it will display more technical information.
Discover All Commands Available on Your System
You want to discover what PowerShell cmdlets available on your system. Simple, 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 sue 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 in a descending order. To archive 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, VS Code, or any favorite editor to create a PowerShell script and save the script with a .ps1 file extension (helloworld.ps1 in the example)
- To run the script, cd to your current folder and type ./helloworld.ps1
See [Running PowerShell Scripts Is as Easy as 1-2-3] run-ps for more details.
More Reading
Books & eBooks & Blogs & Tutorials
- Windows PowerShell in Action by Bruce Payette
- Windows PowerShell Cookbook by Lee Holmes
- eBooks from PowerShell.org
- eBooks List by Martin Schvartzman
- eBooks from PowerShell.com
- 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: Get Started with PowerShell Remoting from Channel9
- 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