Demo Write-Log

Write-Log-Demo-Output.txt

PS /Users/chris> Write-Log "Hello!"                                                                                                                                                                                                                                          
[2018-09-14T08:27:35] Hello!
PS /Users/chris> Get-Content ./somelogfilename.log                                                                                                                                                                                                                           
[2018-09-14T08:27:35] Hello!
PS /Users/chris> 

Write-Log-Demo.ps1

function Write-Log {
  param
  (
    [string]$Message 
  )

  $LogMessage = "[$(Get-Date -Format s)] $Message"

  Write-Output $LogMessage
  $LogMessage | Out-File "somelogfilename.log" -Append

}

Write-Log "Hello!"