Categories

Monthly Archives: September 2013

Winter Scripting Games scheduled

The Winter Scripting Games are tentatively schedule to start 6 January 2014 & run for 4-6 weeks depending on the number of events.

See http://powershell.org/wp/2013/09/29/winter-scripting-games-tentatively-scheduled/ for latest details

PowerShell too big to know

A couple of sentences in the Scripting Guy’s post from yesterday

http://blogs.technet.com/b/heyscriptingguy/archive/2013/09/27/the-powershell-summit-why-you-should-care.aspx

stuck in my mind:

I am not certain I have ever met anyone who knows everything there is to know about Windows PowerShell. In fact, I am not certain I have ever met anyone who knows nearly everything there is to know about Windows PowerShell.

One simple anecdote should put that in context. At the recent PowerShell summit a number of things were demonstrated that had senior members of the PowerShell team saying “I didn’t know you could do that” As an aside similar scenarios played out at the 3 PowerShell Deep Dives in 2011 & 2012.

I’ve been using PowerShell since the early betas for 1.0 & have been an MVP for 6 years and I definitely don’t know everything about PowerShell. I’m learning something new about PowerShell every day.

Think also that it took three of us to write PowerShell in Depth.

There are a whole bunch of modules in Windows 2012 & 2012 R2 I haven’t had time to paly with yet. Add in the PowerShell functionality in SharePoint, Exchange, SQL Server plus all the other Microsoft and third party products and no one can know all there is to know about PowerShell.

One of the great joys of working PowerShell is that there is always something new to learn. Sure, you’re building on what you already know but even the core PowerShell engine can bring surprises.

I’d be highly suspicious of anyone claiming to know everything about PowerShell.

PowerShell Summit 2014–reasons to attend

Microsoft’s Scripting Guy supplies a number of very compelling reasons for attending the PowerShell Summit 2014 in Seattle.

http://blogs.technet.com/b/heyscriptingguy/archive/2013/09/27/the-powershell-summit-why-you-should-care.aspx

 

Registration details can be found here

http://powershell.org/wp/community-events/summit/

 

In addition to the powershell.org you will be able to talk to MVPs, the representatives from the PowerShell team, The Scripting Guy and a whole bunch of people who use PowerShell on a daily basis and probably have the answer to that burning question.

This years’s event was brilliant – next years will be at least as good if not better.

It is the PowerShell event of the year – highly recommended

Rolling back time

 

There are many situations where you want to roll the date back – checking a file’s last access time, processing event logs, checking a password expiry in AD.

Get-Date (or more accurately the underlying System.DateTime .NET class offers a number of options.

Lets say you need a date that’s 3 months in the past. 

You could create it directly:

£> Get-Date -Day 26 -Month 6 -Year 2013

26 June 2013 19:41:42

Alternatively:

£> Get-Date -Date "26 June 2013"

26 June 2013 00:00:00

Notice the difference on the times.  I’m going to ignore the time portion.

Get-Date supplies a number of methods you could use:

Get-Date | Get-Member -MemberType Method

Add
AddDays
AddHours
AddMilliseconds
AddMinutes
AddMonths
AddSeconds
AddTicks
AddYears

£> $ts = New-TimeSpan -Days 91
£> $ts


Days              : 91
Hours             : 0
Minutes           : 0
Seconds           : 0
Milliseconds      : 0
Ticks             : 78624000000000
TotalDays         : 91
TotalHours        : 2184
TotalMinutes      : 131040
TotalSeconds      : 7862400
TotalMilliseconds : 7862400000

 

£> (Get-Date).Add(-$ts)

27 June 2013 19:46:06

£> (Get-Date).AddDays(-$ts.Totaldays)

27 June 2013 19:46:32

£> (Get-Date).AddHours(-$ts.TotalHours)

27 June 2013 19:48:32

£> (Get-Date).AddMinutes(-$ts.TotalMinutes)

27 June 2013 19:49:07

£> (Get-Date).AddSeconds(-$ts.TotalSeconds)

27 June 2013 19:50:18

£> (Get-Date).AddMilliseconds(-$total.TotalMilliseconds)

26 September 2013 19:51:19


£> (Get-Date).AddTicks(-$total.TotalTicks)

26 September 2013 19:51:38

 

You can also do

£> (Get-Date).AddMonths(-3)

26 June 2013 19:52:12


£> (Get-Date).AddYears(-0.25)

26 September 2013 19:52:37

Lots of ways to solve the same problem. While you normally wouldn’t want to calculate a date 3 months in the past based on seconds or ticks the fact that you can use those values opens up other possibilities.

The [datetime] class supplies a good set of methods for manipulating dates. Knowing they are there enables you to use the most appropriate to solve your task.

Server Documentation

No one likes documenting their servers but is a necessary job.  As the start of a series on taking those first automation steps – you’ve learned PowerShell and now you want to put it to use – I have an article on the Scripting Guy blog that shows you how to get started documenting your servers

http://bit.ly/15T5aSK

Enjoy

If you have any ideas for future articles in the series please leave a comment

Select and List

There are many times when I need to do something like this:

get-Whatever | select –first 1 | format-list –property *

Normally its because I need to discover the properties on an object and see some representative data at the same time. If I  just wanted the properties I could use Get-Member.

Getting tired of typing

select –first 1 | format-list –property *

Its a bit repetitive & boring I decided to look at a function to do this for me and ended up with this

function Select1FullList {
param (
[scriptblock]$scriptblock
)
Invoke-Command -ScriptBlock $scriptblock |
Select-Object -First 1 |
Format-List -Property *
}

New-Alias -Name sfl -Value Select1FullList

I decided on a scriptblock as input because I wasn’t sure what I’d be wanting to see. For instance

Get-mailbox | Get-mailboxstatistics

could be be my input.

I also decided to use an alias as this is a command line tool for use while I’m writing code. My feelings on aliases in scripts still stand.

Still deciding if I need to add a computername parameter to give it remoting capabilities.

Any ways its going into my profile for now & we’ll see how it works out.

AD Month of Lunches–Chapt 18 & 19 in MEAP

An updated MEAP has been released for Active Directory Management in a Month of Lunches.  This one adds chapters 18 & 19

  • Chapter 18, "Managing AD trusts"
  • Chapter 19, "Troubleshooting your AD"

The MEAP is available from www.manning.com/siddaway3

Enjoy

PowerShell Hero

PowerShell.org is giving you the chance to nominate your PowerShell hero – someone how has helped you & others with their PowerShell problems.

Details from http://powershell.org/wp/2013/09/20/nominate-your-powershell-hero/

ErrorAction and WarningAction

You’ve all probably done something like this:

£> Get-Process -Name xyz
Get-Process : Cannot find a process with the name "xyz". Verify the process name and call the cmdlet again.
At line:1 char:1
+ Get-Process -Name xyz
+ ~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (xyz:String) [Get-Process], ProcessCommandException
    + FullyQualifiedErrorId : NoProcessFoundForGivenName,Microsoft.PowerShell.Commands.GetProcessCommand

 

First though of many people is to do this

Get-Process -Name xyz -ErrorAction silentlycontinue

Now, thats not good as you don’t know that an error has occurred.  Its better to deal with it rather than suppress it so you wrap it in a try-catch:

£> try {
>> Get-Process -Name xyz -ErrorAction Stop
>> }
>> catch{
>> "oops"
>> }
>>
oops

In reality you would want to do more than say “oops”

There are a number of situations where cmdlets give you a warning rather than an error. if you want to suppress them use –WarningAction.  It has the same options as –ErrorAction

SilentlyContinue. Suppresses the warning message and continues
executing the command.

Continue. Displays the warning message and continues executing
the command. "Continue" is the default value.

Inquire. Displays the warning message and prompts you for
confirmation before continuing execution. This value is rarely
used.

Stop. Displays the warning message and stops executing the
command.

More details in about_Common_Parameters

Using WMI methods with the CIM cmdlets

Using WMI class methods with the CIM cmdlets can cause a lot of confusion. This article, of mine, should clear up that confusion for you.

http://blogs.technet.com/b/heyscriptingguy/archive/2013/09/20/hey-dude-where-are-my-methods.aspx