Comments on: Potential Pipeline Pitfall http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#utm_source=feed&utm_medium=feed&utm_campaign=feed?utm_source=rss&utm_medium=rss&utm_campaign=potential-pipeline-pitfall Advice, solutions, tips and more for the lonely Windows administrator with too much to do and not enough time. Tue, 07 Feb 2012 16:20:17 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Jeffery Hicks http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-822 Jeffery Hicks Tue, 19 Jan 2010 12:18:17 +0000 http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-822 I suppose I should read Bruce's book again. I suppose I should read Bruce’s book again.

]]> By: David "Makovec" Moravec http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-820 David "Makovec" Moravec Tue, 19 Jan 2010 08:48:53 +0000 http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-820 I am reading PowerShell in Action again and this morning I accidentaly found this: "In a pipeline, the begin clause is run for all cmdlets in in the pipeline. Then the process clause is run for the first cmdlet. ... Finally the end clauses are all run." Sequencing is cover again in chapter 7 but I haven't it now on my PC so can't check. But I am sure you have it. David I am reading PowerShell in Action again and this morning I accidentaly found this:

“In a pipeline, the begin clause is run for all cmdlets in in the pipeline. Then the process clause is run for the first cmdlet. … Finally the end clauses are all run.” Sequencing is cover again in chapter 7 but I haven’t it now on my PC so can’t check. But I am sure you have it.

David

]]> By: Jeffery Hicks http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-760 Jeffery Hicks Mon, 11 Jan 2010 20:43:50 +0000 http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-760 I thought I had made that clear. If I have these functions: <code> Function Foo-A { Write-Host "Starting Foo-A" -ForegroundColor green dir $env:temp | where {$_.lastwritetime -gt (Get-Date).AddDays(-1)} Write-Host "Ending Foo-A" -ForegroundColor green } #End A Function Foo-B { begin { Write-Host "Starting Foo-B" -ForegroundColor magenta } process { #Write ("{0} {1} {2}" -f $_.fullname,$_.LastWriteTime,$_.length) # Remove-Item $_.fullname -recurse -whatif write $_.fullname } end { Write-Host "ending Foo-B" -ForegroundColor magenta } } #End B Function Foo-C { Begin { Write-Host "Starting Foo-C" -ForegroundColor Cyan } Process { #not really doing anything write-host "sleeping on $_" -fore Cyan sleep -milliseconds 100 } end { Write-Host "ending Foo-C" -ForegroundColor Cyan } } #End C </code> And then run Foo-A | Foo-B | Foo-C I will get output like this: <code> Starting Foo-B Starting Foo-C Starting Foo-A sleeping on C:\Users\Jeff\AppData\Local\Temp\msohtmlclip1 sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRA4BF.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRB851.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC69E.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC6B5.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC7CF.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRD5D3.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRD8E2.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRE109.tmp.cvr sleeping on C:\Users\Jeff\AppData\Local\Temp\jusched.log Ending Foo-A ending Foo-B ending Foo-C </code> which is what I expect. The begin script blocks run in order, the process script blocks run in order and then the end script blocks run in order. Foo-A is a "standard" function without any defined script blocks. I think we're saying the same thing. I thought I had made that clear. If I have these functions:

Function Foo-A {

    Write-Host "Starting Foo-A" -ForegroundColor green

    dir $env:temp | where {$_.lastwritetime -gt (Get-Date).AddDays(-1)}

    Write-Host "Ending Foo-A" -ForegroundColor green

} #End A

Function Foo-B {

    begin {

      Write-Host "Starting Foo-B" -ForegroundColor magenta
    }

    process {
     #Write ("{0}  {1}  {2}" -f $_.fullname,$_.LastWriteTime,$_.length)
     # Remove-Item $_.fullname -recurse -whatif
     write $_.fullname
    }

    end {
     Write-Host "ending Foo-B" -ForegroundColor magenta
    }

} #End B

Function Foo-C {

    Begin {
     Write-Host "Starting Foo-C" -ForegroundColor Cyan
    }

    Process {
     #not really doing anything
     write-host "sleeping on $_" -fore Cyan
     sleep -milliseconds 100
    }

    end {
      Write-Host "ending Foo-C" -ForegroundColor Cyan
    }
} #End C

And then run Foo-A | Foo-B | Foo-C I will get output like this:

Starting Foo-B
Starting Foo-C
Starting Foo-A
sleeping on C:\Users\Jeff\AppData\Local\Temp\msohtmlclip1
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRA4BF.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRB851.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC69E.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC6B5.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRC7CF.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRD5D3.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRD8E2.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\CVRE109.tmp.cvr
sleeping on C:\Users\Jeff\AppData\Local\Temp\jusched.log
Ending Foo-A
ending Foo-B
ending Foo-C

which is what I expect. The begin script blocks run in order, the process script blocks run in order and then the end script blocks run in order. Foo-A is a “standard” function without any defined script blocks. I think we’re saying the same thing.

]]> By: Joel "Jaykul" Bennett http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-759 Joel "Jaykul" Bennett Mon, 11 Jan 2010 20:14:40 +0000 http://jdhitsolutions.com/blog/2010/01/potential-pipeline-pitfall/#comment-759 I believe that BOTH the begin blocks and END blocks are run in pipeline order. It doesn't looks like that in your output only because you're writing the "begin" message from A from the END block ;-) I believe that BOTH the begin blocks and END blocks are run in pipeline order. It doesn’t looks like that in your output only because you’re writing the “begin” message from A from the END block ;-)

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