Where-Object

In addition to sorting, you may need to limit or filter the output. The Where-Object cmdlet is a filter that lets you control what data is ultimately displayed. This cmdlet is almost always used in a pipeline expression where output from one cmdlet is piped to this cmdlet. The Where-Object cmdlet requires a code block enclosed in braces that is executed as the filter.

Here's an expression to get all instances of the Win32_Service class where the state property of each object equals stopped.

 get-wmiobject -class win32_service | where {$_.state -eq "Stopped"} 

You may want to further refine this expression and format the output by piping to yet another cmdlet:

 PS C:\> get-wmiobject -class win32_service | ` >>where {$_.state -eq "Stopped"} | format-wide >> Alerter                                 ALG AppMgmt                                 aspnet_state BAsfIpM                                 Browser CiSvc                                   ClipSrv clr_optimization_v2.0.50727_32          COMSysApp CVPND                                   dmadmin dmserver                                ERSvc FastUserSwitchingCompatibility          GrooveAuditService GrooveInstallerService                  GrooveRunOnceInstaller helpsvc                                 HidServ NetDDE                                  NetDDEdsdm Netlogon                                NtLmSsp NtmsSvc                                 ose PDEngine                                Pml Driver HPZ12 PolicyAgent                             RasAuto RDSessMgr                               RemoteAccess rpcapd                                  RpcLocator RSVP                                    SharedAccess SQLAgent$CRM                            SQLAgent$MICROSOFTSMLBIZ SQLWriter                               SSDPSRV SwPrv                                   SysmonLog TlntSvr                                 TrkWks upnphost                                UPS VMAuthdService                          VMnetDHCP vmount2                                 VMware NAT Service VSS                                     W3SVC WmdmPmSN                                Wmi wscsvc                                  xmlprov PS C:\> 

In this example we've taken the same Get-Wmiobject expression and piped it through Format-Wide to get a nice two column report.

The key is recognizing that the script block in braces is what filters the object. If nothing matches, the filter then nothing will be displayed.