This post is as much for me as it is for you. I write a lot of PowerShell scripts and they tend to follow a certain pattern. This is my personal boilerplate for PowerShell scripts.

#Requires -Version 3
Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

$stopwatch = [System.Diagnostics.Stopwatch]::StartNew()
$scriptDir = Split-Path -LiteralPath $PSCommandPath
$startingLoc = Get-Location
Set-Location $scriptDir
$startingDir = [System.Environment]::CurrentDirectory
[System.Environment]::CurrentDirectory = $scriptDir

try
{
    # TODO: Insert script here.
}
finally
{
    Set-Location $startingLoc
    [System.Environment]::CurrentDirectory = $startingDir
    Write-Output "Done. Elapsed time: $($stopwatch.Elapsed)"
}

What’s going on here?

• Enables StrictMode to enforce some best practices. ¹
  • Prevents use of variables that have not been initialized.
  • Cannot call non-existent properties on objects.
  • Disallows calling a function like a method, e.g., Do-Something(1 2) instead of Do-Something 1 2.
  • Prohibits creating variables without a name.
• Sets $ErrorActionPreference so that unhandled exceptions will halt the script execution. By default, PowerShell will roll on when an exceptions is thrown and this statement makes my scripts safe by default.
• Set $scriptDir to the directory path of the current script. This may be different than the working directory.
• Set the working directory to the $scriptDir so that relative paths in the script itself can be consistent.
• Most of the time I want to know how long my script takes to run so I include a $stopwatch that will output the elapsed time when the script finishes.
• The try...finally ensures that the elapsed time will output even if the script throws an exception.

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