Viewing object structure

Because objects play such a central role in PowerShell, there are several native commands designed to work with arbitrary object types. The most important one is the Get-Member command.

The simplest technique for analyzing the objects that a command returns is to pipe the output of that command to the Get-Member cmdlet. The Get-Member cmdlet shows you the formal name of the object type and a complete listing of its members. The number of elements that are returned can sometimes be overwhelming. For example, a process object can have over 100 members.

The following command allows you to see all the members of a Process object and page through the output.

Get-Process | Get-Member | Out-Host -Paging

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
add_Disposed                   Method         System.Void add_Disposed(Event...
...

We can make this long list of information more usable by filtering for elements we want to see. The Get-Member command lets you list only members that are properties. There are several forms of properties. The cmdlet displays properties of a type using the MemberType parameter with the value Properties. The resulting list is still very long, but a more manageable:

Get-Process | Get-Member -MemberType Properties

   TypeName: System.Diagnostics.Process

Name                       MemberType     Definition
----                       ----------     ----------
Handles                    AliasProperty  Handles = Handlecount
Name                       AliasProperty  Name = ProcessName
...
ExitCode                   Property       System.Int32 ExitCode {get;}
...
Handle                     Property       System.IntPtr Handle {get;}
...
CPU                        ScriptProperty System.Object CPU {get=$this.Total...
...
Path                       ScriptProperty System.Object Path {get=$this.Main...
...

There are more than 60 properties for a process. By default, PowerShell determines how to display an object type using information stored in XML files that have names ending in .format.ps1xml. The formatting definition for process objects is stored in DotNetTypes.format.ps1xml.

If you need to look at properties other than those that PowerShell displays by default, you can format the output using the Format-* cmdlets.