PowerShell has become one of the most popular scripting languages due to its object-oriented nature. Unlike traditional shells like Command Prompt and Bash which are text-based, PowerShell is built on top of the .NET framework and oriented around objects.
In PowerShell, everything is an object with properties that store information. Therefore, knowing how to retrieve and manipulate object properties is critical for unlocking the full potential of PowerShell.
In this comprehensive guide, you will learn:
- What are objects and properties in PowerShell
- How to use the Get-Member cmdlet to view object properties
- Real-world examples of getting properties of different object types
- Advanced techniques for filtering and selecting properties
- How to extend objects with custom properties
So if you want to level up your PowerShell skills, keep reading!
What are Objects and Properties in PowerShell?
An object in PowerShell represents a real-world entity like a file, process, service etc. Objects have attributes called properties which define the characteristics of that object.
For example, a File object has properties like Name, Length, LastWriteTime etc. Similarly, a Process object has properties like ID, Name, WorkingSet etc.
When you execute commands in PowerShell, the output is returned as objects. For instance, the Get-Process commandlet returns a collection of System.Diagnostics.Process objects.
Understanding this object-based nature is the key that unlocks the full potential of PowerShell.
Introducing the Get-Member Cmdlet
The Get-Member cmdlet allows you to view all properties and methods of an object. It is one of the most useful commands for inspecting objects in PowerShell.
The basic syntax is:
Get-Member -InputObject <Object>You can also pipe any object into Get-Member:
<Command> | Get-MemberNow let‘s look at some examples to understand this better.
Example 1: Getting Process Properties
The Get-Process commandlet returns a collection of System.Diagnostics.Process objects representing the running processes.
We can pipe the output of Get-Process into Get-Member to view the properties exposed by the Process object:
PS> Get-Process | Get-Member
TypeName: System.Diagnostics.Process
Name MemberType Definition
---- ---------- ----------
Handles AliasProperty Handles = Handlecount
Name AliasProperty Name = ProcessName
NPM AliasProperty NPM = NonpagedSystemMemorySize
PM AliasProperty PM = PagedMemorySize
VM AliasProperty VM = VirtualMemorySize
WS AliasProperty WS = WorkingSet
Disposed Event System.EventHandler Disposed
ErrorDataReceived Event System.Diagnostics.DataReceived...
Exited Event System.EventHandler Exited
OutputDataReceived Event System.Diagnostics.DataReceived...
BeginErrorReadLine Method void BeginErrorReadLine()
BeginOutputReadLine Method void BeginOutputReadLine()
CancelErrorRead Method void CancelErrorRead()
CancelOutputRead Method void CancelOutputRead()
Close Method void Close()
CloseMainWindow Method bool CloseMainWindow()
CreateObjRef Method System.Runtime.Remoting.ObjRef ...
Dispose Method void Dispose(), void IDispos...
Equals Method bool Equals(System.Object obj)
GetHashCode Method int GetHashCode()
GetLifetimeService Method System.Object GetLifetimeServ...
GetType Method type GetType()
InitializeLifetimeService Method System.Object InitializeLifet...
Kill Method void Kill()
Refresh Method void Refresh()
Start Method bool Start()
ToString Method string ToString()
WaitForExit Method bool WaitForExit(int millise...
WaitForInputIdle Method bool WaitForInputIdle(int mi...
__NounName NoteProperty string __NounName=Process
BasePriority Property int BasePriority {get;}
Container Property System.ComponentModel.Contai...
EnableRaisingEvents Property bool EnableRaisingEvents {ge...
ExitCode Property int ExitCode {get;}
ExitTime Property datetime ExitTime {get;}
Handle Property IntPtr Handle {get;}
HandleCount Property int HandleCount {get;}
HasExited Property bool HasExited {get;}
Id Property int Id {get;}
MachineName Property string MachineName {get;}
MainModule Property System.Diagnostics.ProcessMod...
MainWindowHandle Property IntPtr MainWindowHandle {get;}
MainWindowTitle Property string MainWindowTitle {get;}
MaxWorkingSet Property IntPtr MaxWorkingSet {get;set;}
MinWorkingSet Property IntPtr MinWorkingSet {get;set;}
Modules Property System.Diagnostics.ProcessMod...
NonpagedSystemMemorySize Property int NonpagedSystemMemorySize...
NonpagedSystemMemorySize64 Property long NonpagedSystemMemorySize...
PagedMemorySize Property int PagedMemorySize {get;}
PagedMemorySize64 Property long PagedMemorySize64 {get;}
PagedSystemMemorySize Property int PagedSystemMemorySize {g...
PagedSystemMemorySize64 Property long PagedSystemMemorySize64...
PeakPagedMemorySize Property int PeakPagedMemorySize {get;}
PeakPagedMemorySize64 Property long PeakPagedMemorySize64 {...
PeakWorkingSet Property int PeakWorkingSet {get;}
PeakWorkingSet64 Property long PeakWorkingSet64 {get;}
PriorityBoostEnabled Property bool PriorityBoostEnabled {g...
PriorityClass Property System.Diagnostics.ProcessPri...
PrivateMemorySize Property int PrivateMemorySize {get;}
PrivateMemorySize64 Property long PrivateMemorySize64 {ge...
PrivilegedProcessorTime Property timespan PrivilegedProcessor...
ProcessName Property string ProcessName {get;}
ProcessorAffinity Property System.IntPtr[] ProcessorAff...
Responding Property bool Responding {get;}
SafeHandle Property Microsoft.Win32.SafeHandles...
SessionId Property int SessionId {get;}
Handle ScriptProperty System.Object Handle {get=$...
NPM ScriptProperty System.Object NPM {get=$this...
PM ScriptProperty System.Object PM {get=$this....
StartTime Property datetime StartTime {get;}
SynchronizingObject Property System.ComponentModel.ISynco...
Threads Property System.Diagnostics.ProcessTh...
TotalProcessorTime Property timespan TotalProcessorTime...
UserProcessorTime Property timespan UserProcessorTime ...
VirtualMemorySize Property int VirtualMemorySize {get;}
VirtualMemorySize64 Property long VirtualMemorySize64 {g...
WorkingSet Property int WorkingSet {get;}
WorkingSet64 Property long WorkingSet64 {get;}
Site Property System.ComponentModel.ISite...
Container Property System.ComponentModel.ICont... As you can see, the Get-Process object exposes a ton of useful properties like ID, Name, CPU times, Memory usage etc. This allows us to gather detailed insights into running processes.
Now let‘s look at how to get properties of other common object types in PowerShell.
Example 2: Getting File/Folder Properties
The Get-ChildItem commandlet returns System.IO.FileInfo and System.IO.DirectoryInfo objects representing files and folders.
We can use Get-Member to reveal their properties:
PS> Get-ChildItem | Get-Member
TypeName: System.IO.DirectoryInfo
Name MemberType Definition
---- ---------- ----------
Create Method System.IO.DirectoryInfo Cre...
CreateObjRef Method System.Runtime.Remoting.Obj...
CreateSubdirectory Method System.IO.DirectoryInfo Cr...
Delete Method void Delete(), void Delete...
Equals Method bool Equals(System.Object ...
GetAccessControl Method System.Security.AccessCont...
GetDirectories Method System.IO.DirectoryInfo[] ...
GetFiles Method System.IO.FileInfo[] GetFi...
GetFileSystemInfos Method System.IO.FileSystemInfo[]...
GetHashCode Method int GetHashCode()
GetLifetimeService Method System.Object GetLifetimeS...
GetObjectData Method void GetObjectData(System....
GetType Method type GetType()
InitializeLifetimeService Method System.Object InitializeLi...
MoveTo Method void MoveTo(string destDirName)
Refresh Method void Refresh()
ToString Method string ToString()
Encrypt Method void Encrypt()
Decrypt Method void Decrypt()
__NounName NoteProperty string __NounName=Directory
Exists Property bool Exists {get;}
Attributes Property System.IO.FileAttributes A...
CreationTime Property datetime CreationTime {get;}
CreationTimeUtc Property datetime CreationTimeUtc {...
Extension Property string Extension {get;}
FullName Property string FullName {get;}
LastAccessTime Property datetime LastAccessTime {g...
LastAccessTimeUtc Property datetime LastAccessTimeUt...
LastWriteTime Property datetime LastWriteTime {g...
LastWriteTimeUtc Property datetime LastWriteTimeUt...
Name Property string Name {get;}
Parent Property System.IO.DirectoryInfo P...
Root Property System.IO.DirectoryInfo R...
TypeName: System.IO.FileInfo
Name MemberType Definition
---- ---------- ----------
AppendText Method System.IO.StreamWriter Append...
CopyTo Method System.IO.FileInfo CopyTo(str...
Create Method System.IO.FileStream Create()
CreateObjRef Method System.Runtime.Remoting.ObjRef ...
CreateText Method System.IO.StreamWriter Create...
Decrypt Method void Decrypt()
Delete Method void Delete(), void Delete...
Encrypt Method void Encrypt()
Equals Method bool Equals(System.Object obj)
GetAccessControl Method System.Security.AccessControl....
GetHashCode Method int GetHashCode()
GetLifetimeService Method System.Object GetLifetimeServ...
GetType Method type GetType()
InitializeLifetimeService Method System.Object InitializeLifet...
MoveTo Method void MoveTo(string destFileName)
Open Method System.IO.FileStream Open(Syst...
OpenRead Method System.IO.FileStream OpenRead()
OpenText Method System.IO.StreamReader OpenTex...
OpenWrite Method System.IO.FileStream OpenWrite()
Refresh Method void Refresh()
Replace Method System.IO.FileInfo Replace(st...
ToString Method string ToString()
__NounName NoteProperty string __NounName=File
Attributes Property System.IO.FileAttributes Attri...
CreationTime Property datetime CreationTime {get;}
CreationTimeUtc Property datetime CreationTimeUtc {ge...
Directory Property System.IO.DirectoryInfo Direc...
DirectoryName Property string DirectoryName {get;}
Exists Property bool Exists {get;}
Extension Property string Extension {get;}
FullName Property string FullName {get;}
IsReadOnly Property bool IsReadOnly {get;}
LastAccessTime Property datetime LastAccessTime {get;...
LastAccessTimeUtc Property datetime LastAccessTimeUtc {g...
LastWriteTime Property datetime LastWriteTime {get;s...
LastWriteTimeUtc Property datetime LastWriteTimeUtc {ge...
Length Property long Length {get;}
Name Property string Name {get;}
The objects returned by Get-ChildItem contain properties like Name, Length, various timestamps etc. These can be used to gather insights about files and folders.
Now that you‘ve seen some examples, let‘s go over some advanced techniques related to getting object properties in PowerShell.
Filtering Properties with Select-Object
While Get-Member shows all properties, we often need only specific properties. The Select-Object cmdlet allows us to filter properties easily:
Get-Process | Select-Object -Property Id, Name, CPUThis returns the Id, Name and CPU usage properties for all processes.
You can also exclude properties using the -ExcludeProperty parameter:
Get-Process | Select-Object * -ExcludeProperty Path This returns all properties except the Path.
Calculating Properties with Select-Object
Select-Object also allows you to calculate custom properties.
For example, to add a PercentCPU property showing the percentage CPU usage:
Get-Process | Select-Object Name,
@{Name=‘PercentCPU‘;Expression={$_.CPU / $_.TotalProcessorTime.TotalSeconds * 100}}You can calculate advanced metrics this way for better analysis.
Selecting Properties by Name with Where-Object
The Where-Object cmdlet allows you to filter objects based on property values.
For example to get only processes named explorer:
Get-Process | Where-Object Name -eq explorerWhere-Object gives you precise control over which objects are returned based on property conditions.
Extending Objects with Add-Member
You can even add custom properties to existing objects using Add-Member:
Get-Process | Add-Member -Name PercentCPU -Value {$_.CPU / $_.TotalProcessorTime.TotalSeconds * 100} -PassThru This dynamically extends Process objects to have a PercentCPU property without needing Select-Object.
Add-Member allows you create enriched objects tailored to your needs.
Summary
That covers the main techniques related to getting and manipulating object properties in PowerShell!
The key takeaways are:
- Get-Member reveals properties of output objects
- Select-Object filters properties and creates custom ones
- Where-Object selects objects based on property conditions
- Add-Member dynamically extands objects with new properties
I hope you now feel empowered to unlock the hidden potential within PowerShell objects! Let me know in the comments if you have any other questions.
