Tag: PowerShell

Did you know you can make PowerShell run any commands you want when you start a shell? This is amazingly useful for gathering information, making settings changes, or kicking off processes – all at shell startup. There are plenty of places that talk about the profiles, so I won’t go into each type, but long story short there are almost 10 different profiles when you account for 32 and 64 bit PowerShell. Some of them are explained in detail here.

For my example here, I am going to deal with the %UserProfile%\My Documents\WindowsPowerShell\profile.ps1 profile, which affects the current user, but all shells. This is useful for when you are switching back and forth between the ISE and console – say when you are testing new scripts. By default this file won’t exist – you will have to create it if it doesn’t.

#See if your profile file exists.  Checks the 'My Documents\WindowsPowerShell' directory
Test-Path $profile

The profile file is really just a .ps1 file. You can put any PowerShell you want in this file. Say you want to get a random Cat Fact every time you start a shell? (who am I to judge?)

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
((((invoke-webrequest -uri https://catfact.ninja/fact -Method get).content).split(':')[1])).trim('","length"')

There are some really useful things you can do now that you know you can run anything. For example – this will show the number of running PowerShell processes, along with WinRM service status:

write-host -ForegroundColor Green "PowerShell Processes: " (Get-process 'PowerShell').count
write-host -ForegroundColor Green "WinRM Status: " (Get-service 'winrm').status

And this will show the PowerShell module paths:

write-host -ForegroundColor Green "Module Paths:"
foreach ($module in ($env:PSModulePath).Split(";")){write-host -ForegroundColor Green "    "$module}

Notice here – I also added a simple “cd c:\blog” to my profile – really useful for starting straight in your scripts directory (no more “cd c:\workspaces\app\development\scripts….” every time you start a console)

But you can do even more! Full functions can be loaded into your profile and are available immediately. One of my favorites is one that will add a Start-RDP function, so I can initiate a remote desktop session without ever touching the start menu! How cool is this?

write-host -ForegroundColor Green "PowerShell Processes: " (Get-process 'PowerShell').count
write-host -ForegroundColor Green "WinRM Status: " (Get-service 'winrm').status
write-host -ForegroundColor Green "Module Paths:"
foreach ($module in ($env:PSModulePath).Split(";")){write-host -ForegroundColor Green "    "$module}
cd C:\Blog
function Start-RDP
{
    param  
    (  
        [Parameter(
            Position = 0,
            ValueFromPipeline=$true,
            Mandatory=$true
        )]
        [ValidateNotNullOrEmpty()]
        [string]
        $ServerName
    )
    mstsc /v:$ServerName 
}

There is also a special function you can put in your profile – it’s the ‘prompt’ function. This will change the PowerShell command line prompt to whatever you want! Just create a new function called ‘prompt’, write-host anything you want into the function, and make sure you put a ‘return ” “‘ at the end – it’s that’s simple! You can put some great data right on the prompt – for example, you can make the current time show up each time the prompt is shown! This is really useful for measuring how long something takes to run if you don’t want to pull out measure-object! Here is my prompt, along with the full profile:

function prompt
{
    $time = "("+(get-date).ToLongTimeString()+")"
    write-host -NoNewline -ForegroundColor Green "PS " (Get-Location).Path $time ">"
    return " "
}
write-host -ForegroundColor Green "PowerShell Processes: " (Get-process 'PowerShell').count
write-host -ForegroundColor Green "WinRM Status: " (Get-service 'winrm').status
write-host -ForegroundColor Green "Module Paths:"
foreach ($module in ($env:PSModulePath).Split(";")){write-host -ForegroundColor Green "    "$module}
cd C:\Blog
function Start-RDP
{
    param  
    (  
        [Parameter(
            Position = 0,
            ValueFromPipeline=$true,
            Mandatory=$true
        )]
        [ValidateNotNullOrEmpty()]
        [string]
        $ServerName
    )
    mstsc /v:$ServerName 
}

And the outcome:

It’s that simple! Customize your profile, and start being productive quicker! Leave a comment below to tell me what your favorite profile modifications are!!

In my day job, I constantly strive to push PowerShell to the limit, attempting to use absolutely every bit of processor/memory/network bandwidth available. One way I do this is with PoshRSJob written by Boe Prox. PoshRSJob is a wonder multi-threading tool, and I use it at pretty heavy scale – typically at a 100 thread throttle.

Sometimes, when you are running a lot of concurrent threads attaching to remote machines, you will run into WinRM connection limitations. They typically will show up in error messages like this when you try to do commands line “invoke-command -computername remoteserver01” :
“This user is allowed a maximum number of 5 concurrent shells, which has been exceeded. “

Configuring typical WSMAN connection limits are fairly well documented, but I was running into another type of error. This error was occurring even after I had upped the connection limits:
“The maximum number of concurrent shells allowed for this plugin has been exceeded.”

This was driving me crazy, until I realized the slightly different wording. Browsing the WSMAN PSDrive, I was eventually able to solve it. The key word in the second error was “plugin”. I had to configure the limits on the plugin, not just the shell. After I realized the difference, I was able to find the right settings. I have compiled them here in a small script that will enable WinRM, and set the limits very high for both the shell and plugin.

enable-psremoting -force 
cd WSMan:\localhost\Shell 
set-item MaxConcurrentUsers 100 
set-item MaxProcessesPerShell 10000 
set-item MaxMemoryPerShellMB 1024 
set-item MaxShellsPerUser 1000 
cd WSMan:\localhost\Plugin\microsoft.powershell\Quotas 
set-item MaxConcurrentUsers 100 
set-item MaxProcessesPerShell 10000 
set-item MaxShells 1000 
set-item MaxShellsPerUser 1000 
restart-service winrm 

Obviously test this before you deploy to production. I also found a neat one-liner to monitor the number of WSMan connections of a target system (set the $computername variable to the target, or use localhost):

while($true){(Get-WSManInstance -ComputerName $ComputerName -ResourceURI Shell -Enumerate).count;start-sleep 1} 

While working on an upcoming blog post, I found myself in the need to create a lot of files filled with random data. I know there are plenty tools out there that will create files, but the bulk of them create empty files – I needed them filled with a considerable amount of text data. So I did what any good PowerShell guy does – I built it myself using ideas from everyone else!

Download the function on GitHub!

Basically we are using the old “Lorem Ipsum” block of text and filling single files until it reaches about the right size. In this example, I am not really concerned about getting the EXACT size. In fact, I included a ‘Variance’ parameter to allow the size to get a bit more random – setting this will make the size of each file larger or smaller by the variance amount. Also included is a pair of parameters that handle sub-directory creation and sub-directory creation chance. At this time it will only go one layer deep, but in future releases I will allow nested subdirectories.

Here is the help text:

<#
	.SYNOPSIS
		Creates a number of auto-generated files in the spcified directories.
	
	.DESCRIPTION
		This function will supply any number of files approximately at the size you request.  Rather than setting a file size, this function actually fills the files with text until they reach the requested size.  You can control the number of files, size of files, and whether or not to create random sub-directories.
	
	.PARAMETER Path
		The top level path where the script will begin to create files.   C:\Temp, for example
	
	.PARAMETER FileTypes
		The types of files to create.  This parameter expects an array of values.  For example:  'log','log1','log2'
	
	.PARAMETER Size
		Size of each individual file.  This parmeter is added to, or subtracted from, by the variance parameter.  This value is in MB.  Exact sizes will vary, and larger file sizes will lead to larger variance.
	
	.PARAMETER Variance
		This parameter is added to, or subtracted from, the Size parameter to get a semi-random file size.  Blocks of text are added to the files, so exact file sizes will be random within a range.
	
	.PARAMETER SubDirectories
		Specify if this script should create subdirectories under the directory specified by the Path parameter.  Directories will have random names similar to file names, and there is a random chance of them being created (specified by the SubDirectoryCreateChance parameter)
	
	.PARAMETER Count
		The number of files to create under the directory specified by the Path parameter
	
	.PARAMETER SubDirectoryCreateChance
		The chance that a subdirectory will be created.  Larger numbers here will actually make it less likely that a subdirectory is created.  A number of 20 means that 1-in-20 will create a subdirectory.  A number of 100 means that 1-100 will create a subdirectory.
	
	.EXAMPLE
		PS C:\> Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 3 -Count 100

	.EXAMPLE
		PS C:\> Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 1 -Count 20000 -SubDirectories True -SubDirectoryCreateChance 50	
	
	.EXAMPLE
		PS C:\> Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 10 -Count 50 -Variance 4 -SubDirectories True -SubDirectoryCreateChance 10
	
#>

Let’s look at the examples:

Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 3 -Count 100

This example will create log files in the c:\temp\blog directory. It will create 100 files with a size of approximately 3MB. It will do so in only one directory.

Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 1 -Count 20000 -SubDirectories True -SubDirectoryCreateChance 50	

This example will create log files in the c:\temp\blog directory. It will create 20,000 files with a size of around 1MB. It has a 1-in-50 chance on each file of putting it in a sub-directory.

Create-Files -Path c:\Temp\blog -FileTypes log, log1, log2, log3, log4, log5, log6, log7, log8 -Size 10 -Count 50 -Variance 4 -SubDirectories True -SubDirectoryCreateChance 10

This final example will create log files in the c:\temp\blog directory. It will create 50 files of approximately 10MB, plus or minus 4MB. It has a 1-in-10 chance of creating subdirectories.

This fun little script is up on GitHub at the link above. Feel free to leave any comments or suggestions! I am already planning to add nested sub-directories, disk space checking, and multi-threading the creation to decrease generation time.

Thanks!