It appears many of you are taken with the possibilities of PowerShell prompt functions. In previous posts, I alluded to the fact that you could do just about anything in a prompt function. Today I have an example of what I am talking about. The challenging… Read the full text.
Using a Stop Watch
In PowerShell, to measure time, you can simply subtract datetime values from another:
$Start = Get-Date $null = Read-Host -Prompt "Press ENTER as fast as you can!" $Stop = Get-Date $TimeSpan = $Stop - $Start $TimeSpan.TotalMilliseconds
An elegant alternative is a stop watch:
$StopWatch = [Diagnostics.Stopwatch]::StartNew() $null = Read-Host -Prompt "Press ENTER as fast as you can!" $StopWatch.Stop() $StopWatch.ElapsedMilliseconds
The specific stop watch advantage is its ability to be paused and continued.
Using Solid Alternatives for $MyInvocation
Lines like $MyInvocation.MyCommand.Definition can be useful to determine the folder in which the current script is stored, i.e. to access other resources located in the same folder.
However, ever since PowerShell 3, there have been easy alternatives to find out the current script name and/or the path to the folder that contains the current script. Run the following code to test for yourself:
$MyInvocation.MyCommand.Definition $PSCommandPath Split-Path -Path $MyInvocation.MyCommand.Definition $PSScriptRoot
If you run these lines interactively (or in an “Untitled” script), they all return nothing. Once you save the script and run the script file, though, the first two lines return the script file path, and the second two lines return the folder path in which the script is located.
The good thing about $PSCommandPath and $PSScriptRoot is that they always contain the same information. $MyInvocation, in contrast, can change, and will change once this variable is read from within a function:
function test { $MyInvocation.MyCommand.Definition $PSCommandPath Split-Path -Path $MyInvocation.MyCommand.Definition $PSScriptRoot } test
Now, $MyInvocation turns out to be useless because it always returns information about who invoked the current script block.
Revised Everything PowerShell Prompt
Since it is Friday and time for some more PowerShell fun, and I’ve been sharing some of my prompt functions, I thought I’d re-share my kitchen sink prompt. This PowerShell prompt function does *a lot* to things and gives you a snapshot view of your system… Read the full text.
Finding Open Firewall Ports
Here is a piece of PowerShell code that connects to the local firewall and dumps the open firewall ports:
$firewall = New-object -ComObject HNetCfg.FwPolicy2 $firewall.Rules | Where-Object {$_.Action -eq 0} | Select-Object Name, ApplicationName,LocalPorts
The result may look similar to this:
Name ApplicationName LocalPorts ---- --------------- ---------- pluginhost.exe C:userstobweappdatalocalskypepluginpluginhost.exe * pluginhost.exe C:userstobweappdatalocalskypepluginpluginhost.exe * spotify.exe C:userstobweappdataroamingspotifyspotify.exe * spotify.exe C:userstobweappdataroamingspotifyspotify.exe *
In Windows 10 and Server 2016, there are finally a number of firewall-specific cmdlets out of the box, too:
PS> Get-Command -Noun *Firewall* CommandType Name Version Source ----------- ---- ------- ------ Function Copy-NetFirewallRule 2.0.0.0 NetSecurity Function Disable-NetFirewallRule 2.0.0.0 NetSecurity Function Enable-NetFirewallRule 2.0.0.0 NetSecurity Function Get-NetFirewallAddressFilter 2.0.0.0 NetSecurity Function Get-NetFirewallApplicationFilter 2.0.0.0 NetSecurity Function Get-NetFirewallInterfaceFilter 2.0.0.0 NetSecurity Function Get-NetFirewallInterfaceTypeFilter 2.0.0.0 NetSecurity Function Get-NetFirewallPortFilter 2.0.0.0 NetSecurity Function Get-NetFirewallProfile 2.0.0.0 NetSecurity Function Get-NetFirewallRule 2.0.0.0 NetSecurity Function Get-NetFirewallSecurityFilter 2.0.0.0 NetSecurity Function Get-NetFirewallServiceFilter 2.0.0.0 NetSecurity Function Get-NetFirewallSetting 2.0.0.0 NetSecurity Function New-NetFirewallRule 2.0.0.0 NetSecurity Function Remove-NetFirewallRule 2.0.0.0 NetSecurity Function Rename-NetFirewallRule 2.0.0.0 NetSecurity Function Set-NetFirewallAddressFilter 2.0.0.0 NetSecurity Function Set-NetFirewallApplicationFilter 2.0.0.0 NetSecurity Function Set-NetFirewallInterfaceFilter 2.0.0.0 NetSecurity Function Set-NetFirewallInterfaceTypeFilter 2.0.0.0 NetSecurity Function Set-NetFirewallPortFilter 2.0.0.0 NetSecurity Function Set-NetFirewallProfile 2.0.0.0 NetSecurity Function Set-NetFirewallRule 2.0.0.0 NetSecurity Function Set-NetFirewallSecurityFilter 2.0.0.0 NetSecurity Function Set-NetFirewallServiceFilter 2.0.0.0 NetSecurity Function Set-NetFirewallSetting 2.0.0.0 NetSecurity Function Show-NetFirewallRule 2.0.0.0 NetSecurity
Your Christmas PowerShell Prompt
Continuing my fun with PowerShell prompts and because we are in the Christmas season. I’m bringing back my Christmas countdown prompt. I have updated so it should work in both the traditional console and PowerShell ISE. The prompt displays a randomly… Read the full text.