Vista - Write-Output is bleeding into a pipe why

Below is a greatly simplified example of what I'm experiencing. Each time
Write-Output is being called it is being piped into my array.

Can anyone explain to me whether its me or PS?

thx
bob
==============
function Parse_Arguments( [object[]] $myargs )
{

echo "in $($MyInvocation.MyCommand.name)"
$i=0
foreach ($arg in $myargs) {echo "`$args[$i] = $($arg)"; $i++}

$Param = $myargs |
foreach {
switch ($_)
{
1 { $e = @{}; $e.a = 1; $e}
}
}

echo "`$Param.count is $($Param.Count)"

foreach ($p in $Param) { echo "`$p is $($p['a'])" }

echo "leaving $($MyInvocation.MyCommand.name)"
$Param
}



$Params = Parse_Arguments $args

## Unless the below statement is uncommented the "echo" statements above
never are written to screen
## $Params

foreach ($p in $Params)
{
## Uncomment the below statement to see what the output of Param[0] -
Param[4] is
## For some reason Write-Output is being piped into Param
$host.EnterNestedPrompt()

switch ($p.a)
{
1 { echo "1" }

Default {echo "Why is the output of `"echo`" being piped into
here?: $([int][char]$_)"}
}
}

To duplicate this write this out as t.ps1 and invoke it as .\t.ps1 1

On Sep 25, 11:32 am, Bob Landau <BobLan...@xxxxxx>
wrote:If you look at the help for Write-Output (Get-Help Write-Output), you
will see that its purpose is to write objects to the pipeline.
Anything in a function that isn't consumed by something else becomes
an output, which is why your Write-Output calls are being combined
with $Params. If you want something to go to the console, and not the
pipeline, use Write-Host.

Jeff

On Sep 25, 3:36 am, Jeff <jeff.hill...@xxxxxx> wrote:....and on that note, is it just me, or did anyone else expect "echo"
to be aliased to write-host, not write-output like it is now? that
surprised me.

- Oisin

I'm not sure about other OS's but "echo" has always written to stdout in
Windows. However the behavior I'm seeing does surprise me.

"Oisin Grehan" wrote:

Thank you Jeff for the explaination.

It's not that I didn't read Write-* cmdlets as well as about_redirection; I
did.

Its just that NO place have I been able to find on the Web, PS official
doc's or my trusty "PS in Action" that the Pipe Operator will gobble up
_everything_ sent to Write-Output _within_ the entire function.

Take a look below again; the pipe operator scope in my opinion should be
piping only the output in the ForEach Scriptblock. I see no reason why it
should be so greedy as to grab everything with the scope of the function.

Does anyone else find this to be as unfriendly as I do?

What I've ended up doing is write the function in a sub-expression and
explictly pipe to Out-Host. Which basically does want you've mentioned
although it does allow me to redirect to a file if I want

bob

"Jeff" wrote:

"Bob Landau" <BobLandau@xxxxxx> wrote in message
news39C1D3D-4538-42D6-BFE8-AD321C6E3AD1@xxxxxxThis is expected. I wrote about this in a blog post title: 'Effective
PowerShell Item 7: Understanding "Output"'. Perhaps you will find it
useful:

http://keithhill.spaces.live.com/blo...3A97!811.entry

--
Keith