?
Solved

powershell remote variables

Posted on 2013-12-30
2
Medium Priority
?
358 Views
Last Modified: 2013-12-30
Can anyone tell me why the following command creates the text file but does not populate it with any data?

Invoke-Command -ComputerName server1 -ScriptBlock {Set-Variable -Name wind -Value 'C:\Windows'}
Invoke-Command -ComputerName server1 -ScriptBlock {Get-ChildItem -Path $wind -name} | Out-File -FilePath C:\test\test.txt

but the following works fine and creates the data

Invoke-Command -ComputerName server1 -ScriptBlock {Get-ChildItem -Path C:\Windows -name} | Out-File -FilePath C:\test\test.txt
0
Comment
Question by:Dead_Eyes
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 40

Accepted Solution

by:
footech earned 800 total points
ID: 39747352
When you use Invoke-Command with the -computername parameter, it establishes a remote session and then terminates it as soon as the scriptblock is complete.  So the variable that you create in the first command no longer exists when you run the second command.  There are a few ways around this.  One is to create a session that will be used for each Invoke-command.  The session will persist until it is manually removed.
$s = New-PSSession -computername server1
Invoke-Command -session $s -ScriptBlock {Set-Variable -Name wind -Value 'C:\Windows'}
Invoke-Command -session $s -ScriptBlock {Get-ChildItem -Path $wind -name} | Out-File -FilePath C:\test\test.txt

Open in new window


Another way is to create a scriptblock which contains all the commands you wish to run, and is executed by a single Invoke-Command command.
$block = { 
  Set-Variable -Name wind -Value 'C:\Windows'
  Get-ChildItem -Path $wind -name
}
Invoke-Command -ComputerName server1 -ScriptBlock $block | Out-File -FilePath C:\test\test.txt

Open in new window


Or if the variable is from the local session and needs to be passed to the remote session.
Set-Variable -Name wind -Value 'C:\Windows'
Invoke-Command -ComputerName server1 -ScriptBlock {param ($wind) Get-ChildItem -Path $wind -name} -ArgumentList $wind | Out-File -FilePath C:\test\test.txt

Open in new window

0
 

Author Closing Comment

by:Dead_Eyes
ID: 39747525
Excellent explanation and very helpful thanks
0

Featured Post

WatchGuard's M Series Appliances - Miecom Approved

WatchGuard's newest M series appliances were put to the test by Miercom.  We had great results and outperformed all of our competitors in both stateless and stateful traffic throghput scenarios! Ready to see how your UTM appliance stacked up? Download the Miercom Report!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article explains how to prepare an HTML email signature template file containing dynamic placeholders for users' Azure AD data. Furthermore, it explains how to use this file to remotely set up a department-wide email signature policy in Office …
A recent project that involved parsing Tableau Desktop and Server log files to extract reusable user queries for use in other systems. I chose to use PowerShell to gather the data, and SharePoint to present it...
Exchange organizations may use the Journaling Agent of the Transport Service to archive messages going through Exchange. However, if the Transport Service is integrated with some email content management application (such as an antispam), the admini…
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…

764 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question