Ezine 166 - Learning PowerShell
Ezine 166 - Learning PowerShell
This ezine is dedicated to persuading people to try PowerShell. I am not
selling anything! You need no money, just the inertia to download the free
PowerShell files from Microsoft's site; then try a few of my
basic ideas and examples.
Topics for PowerShell in Exchange 2007
♣
Don't believe that PowerShell is just for Exchange administrators, nor is it
just for running 'DIR' commands. Equally, don't think - 'Those process
commands are flashy, but are nothing like the real world'. I say again,
PowerShell is the way of the future, you are limited only by your own
imagination, it's the sort of language to dip in to as and when you
need a solution to a computer configuration or interrogation problem.
If you have already started learning PowerShell, be patient with me, this week
I want to tempt more people into the community. Just as anyone can hit
a tennis ball with that big racket, so anyone can type a PowerShell
command. Just as only one in a million are good enough to play tennis at
Wimbledon, so few are good enough at PowerShell to become gurus. My point
is PowerShell is easy to learn the basic strokes and enjoy the game, yet it has
all the intricacies you would expect from a top notch game - sorry, I mean
script language.
I have an overwhelming sense that PowerShell is the future way to configure
at least some of your computer settings.
At the very least I am sure that PowerShell will replace the aging 'DOS' shell.
In my minds eye I see at least three distinct groups of PowerShell learners who
will benefit from this scripting language.
1) Whenever configuring a setting via the command-line is faster than the GUI, then
people will always be attracted to the language. Exchange Administrators have good reason to learn the rudiments of PowerShell
syntax, in particular the -parameter to modify the main verb-Noun cmdlet. Even if you have no desire to
use Exchange 2007, this concept of administrators configuring items by typing
instead of clicking the mouse will spill over into Windows Server 2008 and its
successors.
2) People will transfer from VBScript to PowerShell, particularly if they want
better control over WMI. (Windows Management Instrumentation). The
biggest benefit is efficiency; PowerShell constructions are shorter and
less fussy than the equivalent VBScript commands.
3) As an 'old timer', I must also take into consideration those just starting out in
computing. Newbies have the advantage of no baggage from DOS or other
ancient systems, consequently they will probably learn PowerShell faster than
any of us. One of the best ways to practice with PowerShell is to get
basic information about a) files, b) services, or c) processes. For
example try these three commands:
a) get-Childitem c:\
b) get-service *
c) get-Process |ft ProcessName, cpu -auto
?) Budding programmers who want to develop applets using PowerShell.
This is an area where I confess to being a bit of a dreamer. More so as my
website is geared to the generalist, rather than the
professional programmer. Nevertheless, I want to plant the idea
for prospective script writers to choose PowerShell as a vehicle for
writing their programs. My dream is
that eventually such script writers will do us all a favour by producing nifty
applets.
Calculating IP Address
ranges is a black art, which many network managers solve by creating custom
Excel spreadsheets. IPAT cracks this problem of allocating IP addresses
in networks in two ways:
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
The first pattern to observe is that each PowerShell cmdlet starts with a doing word like, 'get',
'set', or 'start'; this verb is followed by an object, like 'service', 'process', or a myriad
of other operating system handles with strange names. The result is a
basic cmdlet, for example,
get-process, or start-service alerter. Incidentally, top programmers use
only about ten of these verbs, however, they have a huge bank of nouns.
The second pattern to research is the -parameter. Once you have a
cmdlet pair the trick is to gain precise control by appending a modifier or -parameter.
For example, -name, -path or -recurse. Here is an example which lists all
the files under the system32 folder:
get-childitem -path c:\windows\system32\ -recurse (Recurse means drill down through the sub-directories).
The third pattern to master is PowerShell's signature tune - the pipe symbol
(|). This tiny symbol means make the output of the first section | the input of the
second section. For example, list files | send the list to this file:
get-childitem -path c:\windows\
| out-file c:\windows.txt Note 1: Look in the c:\ root directory for a file
called windows.txt
Note 2: You could change the path to: -path c:\windows\system32\
-recurse
It would make my day if you experiment by using
PowerShell for as many different types of task as possible. But don't follow
me slavishly; develop your own PowerShell agenda. Here are ideas of how to
employ PowerShell:
- Repetitive tasks. Change an Active Directory parameter for
different users.
- Research. Find files containing a particular phrase.
- Interrogating the operating system with WMI. How long have I got!
If you have used WMI with VBScript it will be MUCH easier in PowerShell.
- Type at the command-line, because the GUI takes longer. For example,
Exchange 2007 configuration.
- Replace 'DOS' commands. PowerShell invokes built-in commands
such as Ipconfig or NetSh.
Your strategy for installing PowerShell varies depending on your underlying
operating system. Much of the of PowerShell's richness comes from
.Net framework, thus its no surprise that installing .Net framework is a
pre-requisite to installing PowerShell. However, watch out for version conflicts
if you add .Net Framework, 2.0 or 3.0 when you already have applications using
version 1.1.
- Windows Server 2008 - Add Feature (PowerShell is built-in, but dormant
by default)
- Vista, XP, Windows Server 2003. Each of these operating systems requires that you download
a slightly different version from Microsoft's site. Remember to
install .Net framework first.
As of June 2008, the current version is PowerShell 1.0. While there is
a CPT v 2.0 (Community Technology Preview) under development, Guy says stick
with the tried-and-tested version 1.0 until a fully functional version of 2.0 is
released. While learning you want success, and that means a solid
foundation with no flaky new features. The main advantage of version 2.0
will be remote scripting, but that's not a feature you need at the very start of
your PowerShell career.
Go to Microsoft's Download Site
A sign that PowerShell is growing in popularity in the number of books,
forums and add-ons that enthusiasts have developed. While I have bought
two books, I cannot recommend either. My message is no book can cover all
of PowerShell, thus make sure that any book you buy covers the sections that you
are interested in.
Forums:
- Microsoft.Public.Windows.PowerShell
- PowerShellCommunity.org
- powershelllive.com/forums/49/ShowForum.aspx
Microsoft's script center, Microsoft's PowerShell Documentation Pack.
Add-ons Quest:
QAD. 537
If you are looking for handy network utilities, try some of the free downloads at
Tools4Ever
Summary of Learning PowerShell
PowerShell is one of those notions where you have to believe before you can
see. Believe PowerShell is the way of the future and you will see
opportunities every time you sit down at your computer.
If you like this page then please share it with your friends
See more Windows PowerShell tutorials
• PShell Home • Introduction • Dreams •
3 Key Commands •
PowerShell v 3.0
• Process example •
Backtick •
Get-Command •
PowerShell ISE • Cmdlet scripts
• Windows PowerShell •
Set-ExecutionPolicy •
PowerShell examples •
Get-Member
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.
Download my ebook:
Getting Started with PowerShell - only $9.25
You get 36 topics organized into these 3 sections:
1) Getting Started
2) Real-life tasks
3) Examples of Syntax.
In addition to the ebook, you get a PDF version of this Introduction to PowerShell ebook It runs to 120
pages of A4.
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