Advanced Windows PowerShell Scripting Video Training

Advanced Windows PowerShell Scripting Video Training
Advanced Windows PowerShell Scripting Video Training

Saturday, January 23, 2016

How to Read Help Files (Part 4 of 7)

Today we are continuing to look at the PowerShell help files and how to read them.  We are going to explore the detailed help files.  PowerShell can display help at various levels of detail depending on how much information you need.  To access a cmdlets’ detailed help file, just ask for help as you normally would, but add the –Detailed parameter for Get-Help.

Get-Help Stop-Process –Detailed

With the detailed help file you get 2 extra pieces of information the basic help file does not have.  Parameter help and Examples.  Below is a small sample of the parameter help.
    -Force []
        Stops the specified processes without prompting for confirmation. By default, Stop-Process prompts for confirmation before stopping any process that
        is not owned by the current user.
        To find the owner of a process, use the Get-WmiMethod cmdlet to get a Win32_Process object that represents the process, and then use the GetOwner
        method of the object.
        Specifies the process IDs of the processes to be stopped. To specify multiple IDs, use commas to separate the IDs. To find the PID of a process, type
        "get-process". The parameter name ("Id") is optional.

Above is displaying the help files for 2 of the parameters –Force and –ID.  You can see that after the parameter name, the data type the parameter requires is shown.  Remember that even though –ID accepts integer data types, you can sometimes send it an object that can be converted to an integer.  Take a look at the example below.  We identified two instances of Notepad.  We sent Stop-Process an integer value to its –ID parameter in the first instance and a string in the second.  Since the string could be translated to an integer, it worked. Remember to test prior to relying on this functionality.

PS C:\> Get-process -Name Notepad

Handles  NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)     Id  SI ProcessName                                                                                      
-------  ------    -----      ----- -----   ------     --  -- -----------                                                                                     
    141      11     1996       3208 ...63     1.56   2996   1 notepad                                                                                         
    141      11     1992       3112 ...63     3.52  11636   1 notepad                                                                                          

PS C:\> Stop-Process -id 2996

PS C:\> Stop-Process -id "11636"

PS C:\> 

The next added feature of the Detailed help file for a cmdlet is the Example section:
-------------------------- EXAMPLE 1 --------------------------
    PS C:\>stop-process -name notepad
    This command stops all instances of the Notepad process on the computer. (Each instance of Notepad runs in its own process.) It uses the Name parameter to
    specify the processes, all of which have the same name. If you were to use the ID parameter to stop the same processes, you would have to list the process
    IDs of each instance of Notepad.

This is just one example from Stop-Process.  You can see an example Stop-Process –name notepad and a description of what will happen if you execute that example.  A good help file will have multiple examples of how to use the cmdlet.  Take a look at example 4:

     -------------------------- EXAMPLE 4 --------------------------
    PS C:\>get-process lsass | stop-process
    Stop-Process : Cannot stop process 'lsass (596)' because of the following error: Access is denied
    At line:1 char:34
    + get-process lsass  | stop-process <<<<
    [ADMIN]: PS C:\>get-process lsass | stop-process
    Are you sure you want to perform this action?
    Performing operation 'Stop-Process' on Target 'lsass(596)'
    [Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help (default is "Y"):
    [ADMIN]: PS C:\>get-process lsass | stop-process -force
    [ADMIN]: PS C:\>
    These commands show the effect of using the Force parameter to stop a process that is not owned by the user.
    The first command uses the Get-Process cmdlet to get the Lsass process. A pipeline operator sends the process to the Stop-Process cmdlet to stop it. As
    shown in the sample output, the first command fails with an "Access denied" message, because this process can be stopped only by a member of the
    Administrator's group on the computer.
    When Windows PowerShell is opened with the "Run as administrator" option, and the command is repeated, Windows PowerShell prompts you for confirmation.
    The second command uses the Force parameter to suppress the prompt. As a result, the process is stopped without confirmation.

Much more detailed.  Many times I how found examples of what I was looking for in the example section.

Tomorrow we will look at the full help file.

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