PowerShell difference between Write-Host and Write-Output?
What is the difference between Write-Host and Write-Output in PowerShell?
Like...
Write-Host "Hello World";
Write-Output "Hello World";
In a nutshell, Write-Host writes to the console itself. Think of it as a MsgBox in VBScript. Write-Output, on the other hand, writes to the pipeline, so the next command can accept it as its input. You are not required to use Write-Output in order to write objects, as Write-Output is implicitly called for you.
PS> Get-Service
would be the same as:
PS> Get-Service | Write-Output
Write-Output sends the output to the pipeline. From there it can be piped to another cmdlet or assigned to a variable. Write-Host sends it directly to the console.
$a = 'Testing Write-OutPut' | Write-Output
$b = 'Testing Write-Host' | Write-Host
Get-Variable a,b
Outputs:
Testing Write-Host
Name Value
---- -----
a Testing Write-OutPut
b
If you don't tell Powershell what to do with the output to the pipeline by assigning it to a variable or piping it to anoher command, then it gets sent to out-default, which is normally the console so the end result appears the same.
Write-Output sends the data as an object through the pipeline. In the Questions example it will just pass a string.
Write-Host is host dependent. In the console Write-Host is essentially doing [console]::WriteLine.
See this for more info.
Another difference between Write-Host and Write-Output:
Write-Host displays the message on the screen, but it does not write it to the log
Write-Output writes a message to the log, but it does not display it on the screen.
And Write-Host is considered as harmful. You can see a detailed explanation in Write-Host Considered Harmful.