Day: June 29, 2011

You may have a need to run a PS1 script at a certain schedule.  The easiest way to do this is using a bat file.

However, your systems (servers at least!) should have the ExecutionPolicy set to Default which means that no scripts will run.  Bellow is an example of using a bat file to change the ExecutionPolicy just for the current scope that PowerShell.exe is running in and launch the PS1 script.  Once the script is done running, the session is closed and your Execution Policy is still set to Default.

PowerShell.exe -command Set-ExecutionPolicy RemoteSigned -scope Process; C:\PowershellScripts\YourScript.ps1

Let’s say you have a CSV file that you want to import into a hash table.  The contents of the CSV file are as follows:

srv, os

DC1, Windows Server 2008R2Full

Win7, Windows 7

The following code shows the incorrect display as well as the correct one.

# Create a hash table
$HT = @{}
# Import a CSV into the hash table
Import-CSV [your csv file] | foreach {$ht.add($_.”srv”, $_.”os”)}
# The following command doesn’t work
foreach ($i in $ht) {Write-Host $i.values}
# Try this instead
foreach ($i in k$ht.keys) {Write-Host $i “is running” $ht.$i}

Searching AD for a specific attribute using the get-aduser function from the ActiveDirectory PowerShell module.

First the ActiveDirectory module needs to be loaded.  You can check to see if the module is available by typing:

Get-Module -listavailable

If you don’t see the ActiveDirectory module you will need to download the RSAT. 

To load the module type:

Import-Module ActiveDirectory

Search for a specific attribute:

# Searches the entire directory
Get-ADUser -Filter * -Properties * | Where {$_.physicalDeliveryOfficeName -ne "Whatever"

# To set all users who don't have "Whatever" in their Office attribute
Get-ADUser -Filter * -Properties * | Where {$_.physicalDeliveryOfficeName -ne "Whatever" | set-aduser -office "SomethingElse"

When you want to run the Get-Acl cmdlet against a directory, the path property in the results is a bit messy.  Example:

Get-Childitem C:\Labs -recurse | Get-Acl | Format List Path, Owner, Access

We can clean up the Path property by using a custom label with a substring

Get-Childitem C:\Labs -recurse | Get-Acl | Format List @{Label="ShortPath"; Expression= {$_.Path.Substring(38)}},Path, Owner, Access

This week I am teaching a PowerShell v2.0 class at Benchmark Learning.  During the class I usually show the following demo.

# Get the current running processes
$Baseline = Get-Process
# Create some new processes
Calc
Notepad
# Capture the current running processes
$Now = Get-Process
# Compare the two variables
Compare-Object $Baseline $Now

The students thought that was pretty cool, but wanted to know how to kill the processes that were not in the $Baseline variable.  Well, here you go…

# Get the current running processes
$Baseline = Get-Process
# Create some new processes
Calc
Notepad
# Capture the current running processes
$Now = Get-Process
# Compare the two variables
$Processes = Compare-Object $Baseline $Now
foreach ($i in $processes) {$i.inputObject | Stop-Process}