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](./learning-powershell.md#installing-powershell). Getting Familiar with PowerShell Commands --- In this section, you will learn how to - create a file, delete a file and change file directory - find syntax of PowerShell cmdlets - get help if you needed - discover what version of PowerShell you are currently using - exit a PowerShell session - and more 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 />** as it appears on Linux in the following examples. It is shown as **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: ``` PowerShell 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: ```PowerShell 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, ```PowerShell 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 ```PowerShell 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: ```PowerShell 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 ```PowerShell PS /> Set-Location /home PS /home> ``` **5. dir - Get-ChildItem**: list all items in the specified location ```PowerShell 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 ```PowerShell 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.ps1 file exists already, we use **-Force** parameter to replace the existing content. ```PowerShell 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: ```PowerShell 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 ```PowerShell 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: ```PowerShell PS /home/jen> Remove-Item ./test.ps1 ``` **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. ```PowerShell 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" ```PowerShell 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 surf around the Internet. The Get-Help cmdlet also shows you how PowerShell commands work with examples. 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 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 in a descending order. To achieve that, type: ```PowerShell PS /home/jen> dir | sort -Descending ``` Say you want to get the largest file in a directory ```PowerShell 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 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. [run-ps]:http://windowsitpro.com/powershell/running-powershell-scripts-easy-1-2-3 More Reading ---- Books & eBooks & Blogs & Tutorials - [Windows PowerShell in Action][in-action] by Bruce Payette - [Windows PowerShell Cookbook][cookbook] by Lee Holmes - [eBooks from PowerShell.org](https://powershell.org/ebooks/) - [eBooks List][ebook-list] by Martin Schvartzman - [eBooks from PowerShell.com][ebooks-powershell.com] - [Tutorial from MVP][tutorial] - Script Guy blog: [The best way to Learn PowerShell][to-learn] - [Understanding PowerShell Module][ps-module] - [How and When to Create PowerShell Module][create-ps-module] by Adam Bertram - Video: [Get Started with PowerShell Remoting][remoting] from Channel9 - Video: [PowerShell Remoting in Depth][in-depth] from Channel9 - [PowerShell Basics: Remote Management][remote-mgmt] from ITPro - [Running Remote Commands][remote-commands] from PowerShell Web Docs - [Samples for PowerShell Scripts][examples] - [Samples for Writing a PowerShell Script Module][examples-ps-module] - [Writing a PowerShell module in C#][writing-ps-module] - [Examples of Cmdlets Code][sample-code] [in-action]: https://www.amazon.com/Windows-PowerShell-Action-Second-Payette/dp/1935182137 [cookbook]: http://shop.oreilly.com/product/9780596801519.do [ebook-list]: https://blogs.technet.microsoft.com/pstips/2014/05/26/free-powershell-ebooks/ [ebooks-powershell.com]: http://powershell.com/cs/blogs/ebookv2/default.aspx [tutorial]: http://www.computerperformance.co.uk/powershell/index.htm [to-learn]:https://blogs.technet.microsoft.com/heyscriptingguy/2015/01/04/weekend-scripter-the-best-ways-to-learn-powershell/ [ps-module]:https://msdn.microsoft.com/en-us/library/dd878324%28v=vs.85%29.aspx [create-ps-module]:http://www.tomsitpro.com/articles/powershell-modules,2-846.html [remoting]:https://channel9.msdn.com/Series/GetStartedPowerShell3/06 [in-depth]: https://channel9.msdn.com/events/MMS/2012/SV-B406 [remote-mgmt]:http://windowsitpro.com/powershell/powershell-basics-remote-management [remote-commands]:https://msdn.microsoft.com/en-us/powershell/scripting/core-powershell/running-remote-commands [examples]:http://examples.oreilly.com/9780596528492/ [examples-ps-module]:https://msdn.microsoft.com/en-us/library/dd878340%28v=vs.85%29.aspx [writing-ps-module]:http://www.powershellmagazine.com/2014/03/18/writing-a-powershell-module-in-c-part-1-the-basics/ [sample-code]:https://msdn.microsoft.com/en-us/library/ff602031%28v=vs.85%29.aspx