Powershell : Write-Host Vs Write-Output

What is the difference between Write-Host and Write-Output??

I came across a useful article from PowerShell inventor about why you should not use Write-Host in general context unless you want to utilize specific features of it. It is a good read and worth having a peek. To output any data to console it is wiser to use Write-Output instead of Write-Host.

http://www.jsnover.com/blog/2013/12/07/write-host-considered-harmful/

The output returned by Write-Output is passed to pipeline so the functions/cmdlets after the pipeline can read this for further processing. This is not possible if you use Write-Host.

let us examine this behavior with a small example.

function Send-text {            
    write-host "I am sending to console"            

}            
function Send-textwithwriteoutput {            
    write-Output "I am sending to console"            

}            

function Receive-Text {            

    process { write-Host "Received : $_" }            
}

I have three functions

• Send-Text #sends text to console using write-host
• Send-TextWithWriteOutput #sends text to console using write-output
• Receive-Text #receives input from pipeline and shows it

Now look at the below output:

It is very clear from the above output that when sent text to console using write-host, it is not passed to pipeline. But when write-output is used the receive-text function parsed and displayed the value.

Its not that you should not use Write-Host but what I mean is use at the right place. For example, no other cmdlet can replace Write-host cmdlet when you want to apply colors to text you are displaying to console. So, it is wiser to use write-output as a general practice as we expect our code to make the output utilized by other functions/cmdlets.

Hope it is clear. Happy learning.