Comments on: PowerShell Functions and Filters - The basics http://www.powershellpro.com Sharing the Experience Wed, 07 Jan 2009 02:35:13 +0000 http://wordpress.org/?v=2.6.5 By: James http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-223 James Mon, 29 Sep 2008 12:52:18 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-223 I'm playing with the following script to find files older than 1 day. $DateToCompare = (get-date).AddDays(-1) $logFiles = get-childitem C:\logs -recurse | ? {$_.LastWriteTime -lt $DateToCompare} foreach ($f in $logfiles){ Write-Host $f.name } I can send the results via email, however, I need the name and lastwritetime of each file on a new line in the variable sent to the email function. In vb it would be something like: foreach f in fld.files fileformat = fileformat & vbcrlf next SendMail fileformat Anyone know how this is done in PS? Cheers J I’m playing with the following script to find files older than 1 day.

$DateToCompare = (get-date).AddDays(-1)
$logFiles = get-childitem C:\logs -recurse | ? {$_.LastWriteTime -lt $DateToCompare}
foreach ($f in $logfiles){
Write-Host $f.name
}

I can send the results via email, however, I need the name and lastwritetime of each file on a new line in the variable sent to the email function. In vb it would be something like:

foreach f in fld.files
fileformat = fileformat & vbcrlf
next
SendMail fileformat

Anyone know how this is done in PS? Cheers J

]]> By: Gary http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-221 Gary Mon, 22 Sep 2008 23:34:05 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-221 Can someone explain this odd behavior to me? #--- function Test($a, $b) {Write-Host "a=$a, b=$b"} Test("one", "two") #--- I would have expected the above to display "a=one, b=two", but instead it displays "a=one two, b=". Why is this? How would I pass two strings to a function and get the results I expected? Can someone explain this odd behavior to me?

#—
function Test($a, $b) {Write-Host “a=$a, b=$b”}
Test(”one”, “two”)
#—

I would have expected the above to display “a=one, b=two”, but instead it displays “a=one two, b=”. Why is this? How would I pass two strings to a function and get the results I expected?

]]> By: NetGuyDave http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-189 NetGuyDave Thu, 14 Aug 2008 18:38:07 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-189 Jesse, thanks for this excellent tutorial. This is at the perfect level for me, just beginning. Very easy read to get started. ...on to the next one WMI!! Jesse, thanks for this excellent tutorial. This is at the perfect level for me, just beginning. Very easy read to get started. …on to the next one WMI!!

]]> By: Jesse Hamrick http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-187 Jesse Hamrick Wed, 13 Aug 2008 17:34:49 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-187 The issue you are running into is a syntax problem. You are attempting to call a FUNCTION using the syntax for calling another powershell script. Let me give you examples of how to do both: Calling a script that lives outside the main script. Test.ps1 code - Write-Host "Hello World" Caller.ps1 code - .{.\test.ps1} Calling a Function that lives outside the main script. Test.ps1 code - function Hello {Write-Host "Hello Nitin"} Caller.ps1 code - . .\test.ps1 Hello Make sure you understand when you are attempting to call a script or a function within a script that live outside the main script. This tutorial talks about calling functions but you have to follow "click here to find out how" link under Example 2. Calling a Function from another script file. The issue you are running into is a syntax problem. You are attempting to call a FUNCTION using the syntax for calling another powershell script. Let me give you examples of how to do both:
Calling a script that lives outside the main script.
Test.ps1 code -
Write-Host “Hello World”

Caller.ps1 code -
.{.\test.ps1}

Calling a Function that lives outside the main script.
Test.ps1 code -
function Hello {Write-Host “Hello Nitin”}

Caller.ps1 code -
. .\test.ps1
Hello

Make sure you understand when you are attempting to call a script or a function within a script that live outside the main script. This tutorial talks about calling functions but you have to follow “click here to find out how” link under Example 2. Calling a Function from another script file.

]]> By: Nitin http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-173 Nitin Sun, 10 Aug 2008 14:50:55 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-173 I wrote test.ps1 which contains following line - function Hello-World { Write-Host "Hello World" } Then, I wrote caller.ps1 which contains following line - .{'.\test.ps1'} Both the scripts are in the same folder. When I run caller.ps1 file, it does not show "Hello World" on screen. Please tell me where I was wrong. I wrote test.ps1 which contains following line -
function Hello-World { Write-Host “Hello World” }

Then, I wrote caller.ps1 which contains following line -
.{’.\test.ps1′}

Both the scripts are in the same folder. When I run caller.ps1 file, it does not show “Hello World” on screen.

Please tell me where I was wrong.

]]> By: Norman http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-153 Norman Tue, 15 Jul 2008 09:43:26 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-153 One question which I have answered by experiment is to do with the scope of variables when functions are called. For example, what output would you expect from this: $x = 3 function aaa { $x += 1 bbb write-host "aaa: $x" } function bbb { $x += 1 write-host "bbb: $x" } $x aaa $x The answer is that when you refer to a variable in a function, you get the variable that was in scope at the function call (ie dynamic, not lexical scoping) and if you declare a variable in a function it has local scope and masks any same-name global variable. This may seem rather arcane but you need to know these things to tell what will happen! One question which I have answered by experiment is to do with the scope of variables when functions are called. For example, what output would you expect from this:
$x = 3
function aaa {
$x += 1
bbb
write-host “aaa: $x”
}
function bbb {
$x += 1
write-host “bbb: $x”
}
$x
aaa
$x

The answer is that when you refer to a variable in a function, you get the variable that was in scope at the function call (ie dynamic, not lexical scoping) and if you declare a variable in a function it has local scope and masks any same-name global variable. This may seem rather arcane but you need to know these things to tell what will happen!

]]> By: Norman http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-152 Norman Tue, 15 Jul 2008 09:35:39 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-152 @hrp2171 - If I understand PS correctly, the line "$input = get-childitem -path c:\ -recurse" assigns a huge but temporary amount of data to $input, which has to be completed before you go on to the filtering. It would be much faster to do without the $input variable and just pipe the get-childitem directly into the where-object. @hrp2171 - If I understand PS correctly, the line “$input = get-childitem -path c:\ -recurse” assigns a huge but temporary amount of data to $input, which has to be completed before you go on to the filtering. It would be much faster to do without the $input variable and just pipe the get-childitem directly into the where-object.

]]> By: Norman http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-151 Norman Tue, 15 Jul 2008 09:30:34 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-151 Is "snap-in" just copying one text file into another one? (Coming from a Unix environment, some of the Windows jargon is unfamiliar.) Is “snap-in” just copying one text file into another one? (Coming from a Unix environment, some of the Windows jargon is unfamiliar.)

]]> By: sanjeev http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-106 sanjeev Thu, 08 May 2008 14:11:19 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-106 could you please explain something about functions at runtime level. because i tried overloading the function but it is only taking the latest version and not overloading at all. i loved the tutorial.the method and the content is just perfect could you please explain something about functions at runtime level. because i tried overloading the function but it is only taking the latest version and not overloading at all.
i loved the tutorial.the method and the content is just perfect

]]> By: hrp2171 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-97 hrp2171 Mon, 28 Apr 2008 21:14:43 +0000 http://www.powershellpro.com/powershell-tutorial-introduction/powershell-functions-filters/#comment-97 I feel so accomplished. I re-wrote the FindFile function just to see how much I've retained so far and this is what I came up with: Function FindFile { param($fileToFind) $input = get-childitem -path c:\ -recurse $input | where-object{$_.Name -eq "$fileToFind"} } The first time I used the function it took a little while before $input got loaded, but the second time around, it was much quicker. I love this stuff. Can't wait to get into the WMI scripting. I feel so accomplished. I re-wrote the FindFile function just to see how much I’ve retained so far and this is what I came up with:

Function FindFile
{
param($fileToFind)
$input = get-childitem -path c:\ -recurse
$input | where-object{$_.Name -eq “$fileToFind”}
}

The first time I used the function it took a little while before $input got loaded, but the second time around, it was much quicker.

I love this stuff. Can’t wait to get into the WMI scripting.

]]>