MicrosoftВ® Windows PowerShell(TM) Step By Step (Step By Step (Microsoft))

Using the Get-Command cmdlet, you can obtain a listing of all the cmdlets installed on the Windows PowerShell, but there is much more that can be done using this extremely versatile cmdlet. One such method of using the Get-Command cmdlet is to use wild card characters.

This is shown in the following procedure:

Finding commands by using the Get-Command cmdlet

1. Start Windows PowerShell by using Start | Run | Windows PowerShell. The PowerShell prompt will open by default at the root of your Documents And Settings.

2. Use an alias to refer to the Get-Command cmdlet. To find the correct alias, use the Get-Alias cmdlet as follows:

   get-alias g*

3. This command produces a listing of all the aliases defined that begin with the letter g. An example of the output of this command is shown here:

   CommandType Name Definition ----------- ---- ---------- Alias gal Get-Alias Alias gc Get-Content Alias gci Get-ChildItem Alias gcm Get-Command Alias gdr Get-PSDrive Alias ghy Get-History Alias gi Get-Item Alias gl Get-Location Alias gm Get-Member Alias gp Get-ItemProperty Alias gps Get-Process Alias group Group-Object Alias gsv Get-Service Alias gsnp Get-PSSnapin Alias gu Get-Unique Alias gv Get-Variable Alias gwmi Get-WmiObject Alias gh Get-Help

4. Using the gcm alias, use the Get-Command cmdlet to return the Get-Command cmdlet. This is shown here:

   gcm get-command

5. This command returns the Get-Command cmdlet. The output is shown here:

   CommandType Name Definition ----------- ---- ---------- Cmdlet Get-Command Get-Command [[-ArgumentList]...

6. Using the gcm alias to get the Get-Command cmdlet, pipe the output to the Format-List cmdlet. Use the wild card asterisk (*) to obtain a listing of all the properties of the Get-Command cmdlet. This is shown here:

   gcm get-command |format-list *

7. This command will return all the properties from the Get-Command cmdlet. The output is shown here:

   DLL : C:\WINDOWS\assembly\GAC_MSIL\System.Management.Automation\1. 0.0.0__31bf3856ad364e35\System.Management.Automation.dll Verb : Get Noun : Command HelpFile : System.Management.Automation.dll-Help.xml PSSnapIn : Microsoft.PowerShell.Core ImplementingType : Microsoft.PowerShell.Commands.GetCommandCommand ParameterSets : {CmdletSet, AllCommandSet} Definition : Get-Command [[-ArgumentList] <Object[]>] [-Verb <String[]>] [-Noun <String[]>] [-PSSnapin <String[]>] [-TotalCount <Int3 2>] [-Syntax] [-Verbose] [-Debug] [-ErrorAction <ActionPrefe rence>] [-ErrorVariable <String>] [-OutVariable <String>] [- OutBuffer <Int32>] Get-Command [[-Name] <String[]>] [[-ArgumentList] <Object[]> ] [-CommandType <CommandTypes>] [-TotalCount <Int32>] [-Synt ax] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [- ErrorVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>] Name : Get-Command CommandType : Cmdlet

8. Using the gcm alias and the Get-Command cmdlet, pipe the output to the Format-List cmdlet. Use the -property argument, and specify the definition property of the Get-Command cmdlet. Rather than retyping the entire command, use the up arrow on your keyboard to retrieve the previous gcm Get-Command | Format-List * command. Use the Backspace key to remove the asterisk and then simply add -property definition to your command. This is shown here:

   gcm get-command | format-list -property definition

9. This command only returns the property definition for the Get-Command cmdlet. The returned definition is shown here:

   Definition : Get-Command [[-ArgumentList] <Object[]>] [-Verb <String[]>] [-Noun <String[]>] [-PSSnapin <String[]>] [-TotalCount <Int32>] [-Syntax ] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-ErrorVar iable <String>] [-OutVariable <String>] [-OutBuffer <Int32>] Get-Command [[-Name] <String[]>] [[-ArgumentList] <Object[]>] [-Co mmandType <CommandTypes>] [-TotalCount <Int32>] [-Syntax] [-Verbos e] [-Debug] [-ErrorAction <ActionPreference>] [-ErrorVariable <Str ing>] [-OutVariable <String>] [-OutBuffer <Int32>]

10. Because objects are returned from cmdlets instead of simply string data, we can also retrieve the definition of the Get-Command cmdlet by directly using the definition property. This is done by putting the expression inside parentheses, and using a “dotted notation,” as shown here:

    (gcm get-command).definition

11. The definition returned from the previous command is virtually identical to the one returned by using Format-List cmdlet.

12. Use the gcm alias and specify the -verb argument. Use se* for the verb. This is shown here:

    gcm -verb se*

13. The previous command returns a listing of all the cmdlets that contain a verb beginning with se. The result is as follows:

    CommandType Name Definition ----------- ---- ---------- Cmdlet Select-Object Select-Object [[-Property] <... Cmdlet Select-String Select-String [-Pattern] <St... Cmdlet Set-Acl Set-Acl [-Path] <String[]> [... Cmdlet Set-Alias Set-Alias [-Name] <String> [... Cmdlet Set-AuthenticodeSignature Set-AuthenticodeSignature [-... Cmdlet Set-Content Set-Content [-Path] <String[... Cmdlet Set-Date Set-Date [-Date] <DateTime> ... Cmdlet Set-ExecutionPolicy Set-ExecutionPolicy [-Execut... Cmdlet Set-Item Set-Item [-Path] <String[]> ... Cmdlet Set-ItemProperty Set-ItemProperty [-Path] <St... Cmdlet Set-Location Set-Location [[-Path] <Strin... Cmdlet Set-PSDebug Set-PSDebug [-Trace <Int32>]... Cmdlet Set-Service Set-Service [-Name] <String>... Cmdlet Set-TraceSource Set-TraceSource [-Name] <Str... Cmdlet Set-Variable Set-Variable [-Name] <String...

14. Use the gcm alias and specify the -noun argument. Use o* for the noun. This is shown here:

    gcm -noun o*

15. The previous command will return all the cmdlets that contain a noun that begins with the letter o. This result is as follows:

    CommandType Name Definition ----------- ---- ---------- Cmdlet Compare-Object Compare-Object [-ReferenceOb... Cmdlet ForEach-Object ForEach-Object [-Process] <S... Cmdlet Group-Object Group-Object [[-Property] <O... Cmdlet Measure-Object Measure-Object [[-Property] ... Cmdlet New-Object New-Object [-TypeName] <Stri... Cmdlet Select-Object Select-Object [[-Property] <... Cmdlet Sort-Object Sort-Object [[-Property] <Ob... Cmdlet Tee-Object Tee-Object [-FilePath] <Stri... Cmdlet Where-Object Where-Object [-FilterScript]... Cmdlet Write-Output Write-Output [-InputObject] ...

16. Retrieve only the syntax of the Get-Command cmdlet by specifying the -syntax argument. Use the gcm alias to do this, as shown here:

    gcm -syntax get-command

17. The syntax of the Get-Command cmdlet is returned by the previous command. The output is as follows:

    Get-Command [[-ArgumentList] <Object[]>] [-Verb <String[]>] [-Noun <String[]>] [-PSSnapin <String[]>] [-TotalCount <Int32>] [-Syntax] [-Verbose] [-Debug] [-Er rorAction <ActionPreference>] [-ErrorVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>] Get-Command [[-Name] <String[]>] [[-ArgumentList] <Object[]>] [-CommandType <Co mmandTypes>] [-TotalCount <Int32>] [-Syntax] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-ErrorVariable <String>] [-OutVariable <String>] [-OutBuff er <Int32>]

18. Try to use only aliases to repeat the Get-Command syntax command to retrieve the syntax of the Get-Command cmdlet. This is shown here:

    gcm -syntax gcm

19. The result of this command is the not the nice syntax description of the previous command. The rather disappointing result is as follows:

    Get-Command

20. This concludes the procedure for finding commands by using the Get-Command cmdlet.

    Quick Check

    Q. To retrieve a definition of the Get-Command cmdlet, using the dotted notation, what command would you use?

    A. (gcm get-command).definition