Hardest way to set a PATH

In a previous post I hacked together a cumbersome Powershell statement when I tried to set a path from the shell in a way that anyone could use. And it also had to be persistent.

Using $env:Path only sets the path for that session so it wasn't an option since it would leave people hanging when they restarted the shell.

It kinda stumped me for a while because I found it disturbingly ugly but didn't want to go off on a tangent to set up a function. So here is that tangent!

Open up powershell and set your execution policy unless you've already done so.

PS C:\> Set-ExecutionPolicy Unrestricted -Scope CurrentUser

then enter

PS C:> $profile

This will give you the path to your startup script, the file will not exist unless you've set it up before. This script runs every time you open a PowerShell.

Go create that file and open it in your prefered text editor. Then paste the following two functions into it.

function Add-Path { 
  param ( 
    [Parameter(Mandatory=$true, ValueFromPipeline=$true)]
    $Path 
  )

  if (-not (Test-Path -LiteralPath $Path -IsValid)) {
    Write-Output "'$Path' is not a valid path."
    return 
  }

  $EnvironmentScope = "User"
  $PATHVariable = [environment]::GetEnvironmentVariable("PATH", $EnvironmentScope)
  $ExistingPaths = $PATHVariable.Replace(";;", ";").Split(";")
  if ($ExistingPaths.Contains($Path)) {
    Write-Output "'$Path' is already in your environment PATH." 
  } else {
    $UpdatedPATHVariable = [system.String]::Join(";", $ExistingPaths + $Path).Replace(";;", ";") 
    [environment]::SetEnvironmentVariable("PATH", $UpdatedPATHVariable, $EnvironmentScope) 
  }
}

function Remove-Path {
  param ( 
    [Parameter(Mandatory=$True, ValueFromPipeline=$True)]
    $Path
  )

  $EnvironmentScope = "User"
  $RemainingPaths = New-Object System.Collections.Generic.List[String]
  foreach ($existingPath in [environment]::GetEnvironmentVariable("PATH", $EnvironmentScope).Replace(";;", ";").Split(";")) {
    if (-not $existingPath.Equals($Path)) {
      $RemainingPaths.Add($existingPath)
    }
  }

  [environment]::SetEnvironmentVariable("PATH", [system.String]::Join(";", $RemainingPaths), $EnvironmentScope)
}

Now adding and removing a path to your PATH variable is as easy as

PS C:> Remove-Path C:\MyOldPath
PS C:> Add-Path C:\MyNewPath

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