Skip to main content

Avoid Displaying Information

When teaching PowerShell, I use Write-Host often just to display what is going on.  It may be to show the result of an IF or SWITCH construct.  Maybe to let us know that a value incremented.  In practice, I avoid placing text on the screen unless the user specifically asks for it. Write-Host places information directly onto the screen.  Write-Verbose and Write-Information places information in a data stream that eventually ends up on your screen.  This is bad for a few reasons.

First of all, the extra screen candy can be frustrating to watch.  Second, it takes time to write anything to the screen.  This is never good.  You should only display information if necessary and give the user a chance to suppress that information.  I decided to do a little test between Write-Host, Write-Verbose, Write-Information, and displaying nothing.  The code below loops 100 times for each command and again where nothing is performed in the loop.

Function Test-DisplayHost
{
    For($X = 0 ; $X -lt 100 ;$X++)
    {
        Write-Host "Write-Host $X" -ForegroundColor green
    }
}

Function Test-DisplayVerbose
{
    For($X = 0 ; $X -lt 100 ;$X++)
    {
        Write-Verbose "Write-Verbose $X" -Verbose
    }
}

Function Test-DisplayInformation
{
    For($X = 0 ; $X -lt 100 ;$X++)
    {
        Write-Information "Write-Information $X" -InformationAction Continue
    }
}

Function Test-NoDisplay
{
    For($X = 0 ; $X -lt 100 ;$X++)
    {
      
    }
}

Write-Host "Testing Write-Host" -ForegroundColor Cyan
$WriteHost = Measure-Command -Expression {
    Test-DisplayHost

}

Write-Host "Testing Write-Information" -ForegroundColor Cyan
$WriteVerbose = Measure-Command -Expression {
    Test-DisplayVerbose

}

Write-Host "Testing Write-Information" -ForegroundColor Cyan
$WriteInformation = Measure-Command -Expression {
    Test-DisplayInformation

}

Write-Host "Testing Nothing" -ForegroundColor Cyan
$WriteNoting = Measure-Command -Expression {
    Test-NoDisplay

}

Write-Host "Write-Host        | $($WriteHost.Ticks)"
Write-Host "Write-Verbose     | $($WriteVerbose.Ticks)"
Write-Host "Write-Information | $($WriteInformation.Ticks)"
Write-Host "Write nothing     | $($WriteNoting.Ticks)"

Here is the final output:

Write-Host        | 1167467
Write-Verbose     | 400858
Write-Information | 599326
Write nothing     | 6445

Two things that I took note of when running this code multiple times. The first is Write-Host always took longer.  The second, not displaying anything is always faster. 

The lessons learned here is to use Write-Verbose and Write-Information.  This allows the user to call the extra screen candy if they want, and suppress it when they do not.  Remember that Write-Information is a PowerShell 5 cmdlet.


Comments

Popular posts from this blog

Adding a Comment to a GPO with PowerShell

As I'm writing this article, I'm also writing a customization for a PowerShell course I'm teaching next week in Phoenix.  This customization deals with Group Policy and PowerShell.  For those of you who attend my classes may already know this, but I sit their and try to ask the questions to myself that others may ask as I present the material.  I finished up my customization a few hours ago and then I realized that I did not add in how to put a comment on a GPO.  This is a feature that many Group Policy Administrators may not be aware of. This past summer I attended a presentation at TechEd on Group Policy.  One organization in the crowd had over 5,000 Group Policies.  In an environment like that, the comment section can be priceless.  I always like to write in the comment section why I created the policy so I know its purpose next week after I've completed 50 other tasks and can't remember what I did 5 minutes ago. In the Group Policy module for PowerShell V3, th

Return duplicate values from a collection with PowerShell

If you have a collection of objects and you want to remove any duplicate items, it is fairly simple. # Create a collection with duplicate values $Set1 = 1 , 1 , 2 , 2 , 3 , 4 , 5 , 6 , 7 , 1 , 2   # Remove the duplicate values. $Set1 | Select-Object -Unique 1 2 3 4 5 6 7 What if you want only the duplicate values and nothing else? # Create a collection with duplicate values $Set1 = 1 , 1 , 2 , 2 , 3 , 4 , 5 , 6 , 7 , 1 , 2   #Create a second collection with duplicate values removed. $Set2 = $Set1 | Select-Object -Unique   # Return only the duplicate values. ( Compare-Object -ReferenceObject $Set2 -DifferenceObject $Set1 ) . InputObject | Select-Object – Unique 1 2 This works with objects as well as numbers.  The first command creates a collection with 2 duplicates of both 1 and 2.   The second command creates another collection with the duplicates filtered out.  The Compare-Object cmdlet will first find items that are diffe

How to list all the AD LDS instances on a server

AD LDS allows you to provide directory services to applications that are free of the confines of Active Directory.  To list all the AD LDS instances on a server, follow this procedure: Log into the server in question Open a command prompt. Type dsdbutil and press Enter Type List Instances and press Enter . You will receive a list of the instance name, both the LDAP and SSL port numbers, the location of the database, and its status.