Ezine 196 – Learn PowerShell 2.0

Ezine 196 – Learn PowerShell 2.0 Commands

If one of your New Year resolutions is to learn something new, then PowerShell v 2.0 is a great choice.  Of all the scripting programs in the world, no package enables you do more as quickly and with so few instructions, as PowerShell.  My mission is to help you learn PowerShell via a series of 10 ezines.  If you are in a hurry, check out back-numbers that I have already published.

Topics for Learning PowerShell v 2.0 Commands

• This Week’s Secret
• This Week’s Mission to Get Up and Running with PowerShell
• Issuing Simple PowerShell Commands
• What’s New in PowerShell 3.0

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This Week’s Secret

The benefits of learning PowerShell maybe more long-term than you realized.  In the old days you may have been a whiz kid with Windows 3.1’s file manager, but you could not call yourself a techie unless you spoke DOS proficiently.  Now as we enter the twenty tens or tweens, even if you have mastered the latest Windows Explorer you cannot claim to be a top administrator unless you know the basics of PowerShell.

Discovering PowerShell is like cooking, in that even amateurs can knock up a meal, yet professionals can do so much more with same ingredients.  My point is that you will see a huge range of abilities at PowerShell, don’t be put-off when you see the pros make dazzling programs with flashy code.  You can collect a tremendous amount of information by just using simple one-line commands.

Please hold the thought that learning PowerShell is not about jumping on the latest bandwagon, it really will save you time, and it will extend what you can achieve in the way of configuring a computer.

This Week’s Mission to Get Up and Running with PowerShell

The start of a new decade is a classic time to master a new skill.  My mission is simple, to get you up and running with PowerShell v 2.0.  In this ezine I will explain how to download the program and then start issuing simple PowerShell commands.

The Basics – Installing PowerShell v 2.0

How to launch PowerShell depends very much on your operating system.  Select the procedure appropriate for your version of Windows, then find the shortcut to PowerShell ISE (the GUI version).  If you cannot see a link, try Start Menu, Search and type ‘powershell’.

Windows 7
With modern operating systems such as Windows 7 or Windows Server 2008.  PowerShell is built-in to the operating system; therefore all you need to do is go to the Control Panel and ‘Turn Windows feature on’. (Select PowerShell!)

Vista or XP
With operating systems such as Vista, that were around before PowerShell 2.0 RTM was developed, you need to visit Microsoft’s Support, and SCROLL DOWN and find Windows Management Framework Core, then select the appropriate PowerShell / Framework package for your computer.

Warning for Vista and XP only
Guy says: Compared with other Microsoft software packages, which are easy to get and install, the procedure for finding PowerShell v 2.0 is confusing.  Paradoxically, once you realise searching for the .msi package is harder then usual, then getting your copy becomes easy.  Trap: Avoid the CTP versions which often come to the top of any internet search for PowerShell.

Once you get a local copy, double click the .msi file and follow the setup instructions, watch out for instructions to install .Net Framework.

PowerShell v 1.0
In truth, Microsoft has not rewarded those who installed v 1.0 with an easy upgrade path.  Those early adopters will have to uninstall PowerShell v 1.0 and then install version 2.0 together with the latest .Net Framework.  This is not a trivial task; seek extra information on the Microsoft Support website.

WinRM
The killer feature of PowerShell v 2.0 is remoting, which means issuing commands at your computer which are then run on another network machine.  For Vista and older machines this could mean an additional download of WinRM.  My advice is to get started with the basic PowerShell 2.0, and only when you have got it running take a timeout and get WinRM working.  I suggest this not because remoting is unimportant, but because psychologically, building on success makes learning satisfying, whereas grappling with too many new systems risks failure and frustration.

Issuing Simple PowerShell Commands

For the following commands I am assuming that you have launched PowerShell, preferably the ISE or GUI version.  Our mission is to start interrogating the operating system using the built-in verb-Noun commands called cmdlets.  To this day, when I am learning a new PowerShell technique I like to have the GUI version open so that I can troubleshoot.  Once I have mastered the technique I abandon the GUI and work solely in PowerShell.  If it would help you understand what’s we are trying to achieve, try opening the Windows Explorer alongside PowerShell.

List Files in the System32 Folder

You are most welcome to copy these commands and paste them into PowerShell.  Actually, you would getter better feel for the language if you typed them.

Note 1: Try adding the filter  *.exe after ChildItem:
get-ChildItem -path *.exe C:\windows\system32

Try other locations for -path, for example C:\Program Files

Note 2: Observe that "Program Files" has a space, this is why we enclose this path in double quotes.

Note 3: By all means try without -recurse.  The point is that this parameter enables us to drill down into sub-directories.  To see more parameters for any cmdlet call for help thus: get-Help get-ChildItem -full.

Select Properties and Sort

One of the most useful of all PowerShell’s command is get-Member; its purpose is to reveal more properties and methods for another cmdlet, in this way we can make better scripts.

Note 4: Observe the | symbol.  This tells PowerShell to pipe the output of the first command (get-ChildItem) into the second part (get-Member)

Next, we can use the Directory property to sort, and also the Directory and Name properties in the table output.

Note 5: Observe the backtick `.  This tells PowerShell that the same command continues on the next line.  Remember in PowerShell, as with most script languages, there is no word-wrap, consequently a new line would normally mean a fresh command.

Challenge 1:  Try sorting on different properties, for instance Name.  Also try selecting more properties in the output, for example, CreationTime. See more on Get-ChildItem -Exclude parameter.

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For Mr Organized there is a nifty subnet calculator, you enter the network address and the subnet mask, then IPAT works out the usable addresses and their ranges. 

For Mr Lazy IPAT discovers and then displays the IP addresses of existing computers. Download the Free IP Address Tracker

Investigate more PowerShell cmdlets (verb-Noun pairs)

Discover which other cmdlets contain the verb ‘get’.

Challenge 2: I would not want you think that ‘get’ is the only verb, so please try this:
get-command -noun service

Note 6: PowerShell invariably uses singular nouns, thus we type: Service (and not ServiceS)

List Services

Note 7: A little ‘reverse engineering’ may help here.  get-Service | get-Member will once again unearth the properties.  Plain get-Service will reveal two values for status: Stopped and Running.  I admit that the Where{clause} is a bit of a jump from what we have done so far.  But now that I regard you as a member of the scripters’ fraternity we all learn by copying other people’s code!

Note 8:  Attention to detail, PowerShell is obsessed with the minus sign, thus it’s -eq (not =).  One more point, ‘Running’ needs to be in single quotes.

Observation:  My whole rationale is to get people started.  However, I want to emphasise that PowerShell has all the pure programming techniques of VBScript and other scripting languages, it’s just that for beginners I choose not to employ them.  I regard PowerShell as a dual purpose language, people can master simple administrative commands in half an hour, yet it would take a year of full time study before you got to the bottom of what PowerShell can achieve.

Putting this knowledge to use – Restart the Spooler Service

Once your introduction stage is over you will want to look for PowerShell scripts that are going to save you time.  For instance, should a service such as the spooler be giving trouble, you can often cure the problem by restarting the service rather than rebooting the machine.  If you regularly have PowerShell open, it’s quicker to type the following command then to ferret around with the Services snap-in.

Note 9: If this command does not work.  Have a brief study of the error message, but probably the best fix is to close the PowerShell ISE, then re-launch by right-clicking and select ‘Run as Administrator’.  For more troubleshooting launch the computer’s ‘Services’ and see if you can manually restart the (print) spooler.

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Summary of Learning PowerShell v 2.0.

Three ‘takeaways’: Investigate a cmdlets parameters with get-help verb-noun -full.  To list the properties of any cmdlet append | get-Member.  Research more cmdlets with get-Command.

Guy Recommends: Tools4ever’s UMRA

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See more Microsoft PowerShell tutorials

• Introduction  • Dreams  • 3 Key Commands  • Cmdlet scripts  • Real life tasks

• Remote PowerShell  • -Online  • WinRm and WSMan  • Learn PowerShell

• PowerShell Home  • Microsoft PowerShell

Please email me if you have a better example script. Also please report any factual mistakes, grammatical errors or broken links, I will be happy to correct the fault.