Travis Plunk
7bf4641444
Fix broken URL - Also, move other static analysis tests into that CI. - Also, make the link analysis a pester test (partly to make sure the step fails in case of an error)
11 KiB
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.
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 is 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
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.
Get-Alias: Gets the aliases for the current session.
PS /> Get-Alias
CommandType Name
----------- ----
…
Alias cd -> Set-Location
Alias cls -> Clear-Host
Alias clear -> 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 or clear is an alias of Clear-Host.
Now try it:
PS /> Get-Process
PS /> cls
cd -> Set-Location: Sets the current working location to a specified location.
PS /> Set-Location /home
PS /home>
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.
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!
del -> Remove-Item: Deletes the specified items.
This cmdlet will delete the file /home/jen/test.txt:
PS /home/jen> Remove-Item ./test.txt
$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 6.0.0-alpha
PSEdition Core
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 3.0.0.0
GitCommitId v6.0.0-alpha.12
CLRVersion
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
Exit: To exit the PowerShell session, typeexit.
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-Object -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 Visual Studio Code or your favorite editor to create a PowerShell script and save it with a .ps1 file extension.
For more details, see Create and Run PowerShell Script Guide
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