Welcome to the world of PowerShell Objects, where scripting and automation reach new heights of efficiency and flexibility! PowerShell, a powerful and versatile scripting language developed by Microsoft, empowers you with the ability to work with PowerShell Objects– the building blocks that enable seamless data manipulation and automation.
In this comprehensive guide, we’ll delve into the depths of PowerShell Objects, uncovering their true potential and revealing the secrets to optimizing your scripts. Whether you’re a seasoned developer or a beginner eager to learn, our step-by-step tutorials and expert tips will equip you with the knowledge to leverage PowerShell Objects effectively.
What Are PowerShell Objects?
In PowerShell, an object is a fundamental data structure that represents information. It goes beyond simple text and allows you to store and manipulate data along with its associated properties and methods. PowerShell objects are at the core of the language’s power and versatility.
An PowerShell Objects consists of:
- Properties: These are the attributes or data fields associated with the object. Properties can contain various types of data, such as strings, integers, dates, arrays, or other objects.
- Methods: Methods are actions or behaviors that an object can perform. They enable you to interact with and manipulate the object’s data. By invoking methods on an object, you can execute specific tasks related to that object.
PowerShell comes with many built-in PowerShell Objects types, such as strings, numbers, arrays, hashtables, and more. Additionally, you can create custom objects with your own properties and methods, giving you the flexibility to design data structures that suit your specific needs.
When you run PowerShell commands or scripts, they often return objects as output. PowerShell automatically formats and displays these objects in a human-readable way. This makes it easier for users to understand and work with the data.
The ability to pass objects from one command to another using the pipeline (|) is a powerful feature of PowerShell. This allows you to chain commands together, enabling complex operations with ease.
What Are PowerShell Objects Properties?
An PowerShell Objects is described by a number of attributes. These are the attributes of the object. These are specified by the developer who created the object, though you will eventually learn how to add your own in PowerShell. Let’s focus on the boat for the moment. You cannot update some properties because they are read-only. Once it is made, a ship, for instance, might have these fixed characteristics. You can only obtain them.
- Length
- Capacity
- GrossWeight
- Model
- Manufacturer
- SerialNumber
- ManufactureDate
Some properties may also be nested objects. There is most certainly an Engine property in the boat example. Value, however, is a totally distinct item with its own set of characteristics.
- Color
- Name
- Owner
- PurchaseDate
- IsDocked
- Value
The values for each of these characteristics will also be types of PowerShell Objects. But do not fret. Text ([string]), numbers ([int]), and dates ([datetime]) are a few examples of the kind of data I’m referring to. These parameters all define how the boat is right now.
Use a dot notation to refer to any of these attributes. A reference to the object, such as a variable, is on the left. The name of the property is on the right side.
- Engine [boat property]
- horsepower
- manufacturer
- type (inboard or outboard)
- MaxSpeed
- InstallDate
Example for the Object In PowerShell
A collection of process objects can be obtained with Get-Process or get-service. Many of the properties in these objects are read-only, which means you can only get them, as you can see if you pipe them to Get-Member. Other attributes could be set, though. Additionally, there are techniques for ending processes. The associated cmdlets are what matters, not necessarily knowing how to use the methods.
get-process -name notepad | stop-process
The fact that things might change inside the pipeline makes working with objects in PowerShell perhaps the trickiest aspect.
Despite the fact that the operation began with process objects, Group-Object’s creation of the final object is of a different type. The pipelined statement “Get all processes where there is a Company property” makes it easier for me to understand what is going on.
After that, group the outcomes based on the Company attribute, and then order the group objects by Name and Count in descending order.
Because I discovered the Company attribute on Process objects, this works. moreover, GroupInfo objects have the Count, and Name fields. I never once considered parsing or grepping any of the text that was displayed on the screen. This was a simple process that didn’t involve any programming or scripting thanks to PowerShell’s object-oriented design.
Use PowerShell Objects For The Pipeline
Here is a formula I recently found online as a suggested way to obtain a list of active Hyper-V machines with names that begin with CHI. This expression also functions by saving data to a text file. It has been somewhat modified to meet my surroundings.
$vms = get-vm | where {$_.name.startswith("CHI") -and $_.state -eq "running"}
$date = get-date
$vms | foreach {
$msg = "{0}`t{1}`t{2}`t{`3}`t{4}" -f $Date,$_.status,$_.uptime,$_.state,$_.name
$msg >> c:\work\vms.txt
}
The PowerShell solution, in contrast, does little to embrace the PowerShell paradigm, in my opinion. I get the impression from code like this that the author is still trying to alter text and isn’t considering using cmdlets that publish objects to the pipeline.
Once you adopt that mentality, PowerShell is simpler to write and has greater versatility. Although the Get-VM cmdlet is used in this example, the concepts I wish to discuss are applicable to other cmdlets.
When a cmdlet does not provide filtering, use Where-Object.
Since this cmdlet lacks any filtering features, we’ll have to fall back on the PowerShell Where-Object cmdlet. It’s alright. We want to take advantage of every opportunity to filter data at the beginning, though. Actually, the virtual machine name should be used to limit the results as another filtering criterion.
The help says we can’t use a wildcard for the name, yet in theory we could. The help isn’t usually accurate, though I always advise reading it.
​Get-VM -name "chi*" | where {$_.state -eq "running"}
Select-Object can be used to display properties.
The initial need was to show a few homes. Use Select-Object to do it if you must.
Get-VM -name "chi*" | where {$_.state -eq "running"} | Select Status,Uptime,State,Name
To save the outcomes to a text file, use Out-File.
The results of the original command are saved to a text file as the last component. The heritage redirection character, >>, was utilized in the original code. It does the job, but I’m not a big fan of using it because it adds nothing to the PowerShell party. Controlling the encoding is one of the advantages.
Get-VM -name "chi*" | where {$_.state -eq "running"} |
Select @{Name="Date";Expression={Get-Date}},Status,Uptime,State,Name |
Format-Table |
Out-File -FilePath d:\work\vms.txt -Encoding ascii
