adding path cleanup utility Reset-PWSHSystemPath.ps1 (#6892)

tools/windows/Reset-PWSHSystemPath.ps1

@@ -0,0 +1,77 @@
+<#
+.SYNOPSIS
+  Idempotently removes extra PowerShell Core paths from the machine, user and/or process environment scope with no reordering.
+
+.DESCRIPTION
+  Defaults to machine scope and leaving the last sorted path alone.
+  Does not touch path if there is nothing to clean.
+  Emits one simple log line about it's actions for each scope.
+
+  Also accessible in the powershell-core Chocolatey package by using -params '"/CleanUpSystemPath"'
+
+.PARAMETER PathScope
+  Set of machine scopes to clean up.  Valid options are one or more of: Machine, User, Process.
+  Default: machine
+
+.PARAMETER RemoveAllOccurences
+  By default the cleanup leaves the highest sorted PowerShell Core path alone.
+  This switch causes it to be cleaned up as well.
+  Default: false
+
+.EXAMPLE
+  .\Reset-PWSHSystemPath.ps1
+
+  Removes all PowerShell core paths but the very last one when sorted in ascending order from the Machine level path.
+  Good for running on systems that already has at least one valid PowerShell install.
+
+.EXAMPLE
+  .\Reset-PWSHSystemPath.ps1 -RemoveAllOccurences
+
+  Removes ALL PowerShell core paths from the Machine level path.
+  Good for running right before upgrading PowerShell core.
+.EXAMPLE
+  .\Reset-PWSHSystemPath.ps1 -PathScope Machine, User, Process
+
+  Removes all paths but the very last one when sorted in ascending order.
+  Processes all path scopes including current process.
+.EXAMPLE
+  .\Reset-PWSHSystemPath.ps1 -PathScope Machine, User, Process -RemoveAllOccurencs
+
+  Removes all paths from all path scopes including current process.
+#>
+param (
+  [ValidateSet("machine","user","process")]
+  [string[]]$PathScope="machine",
+  [switch]$RemoveAllOccurences
+)
+
+#Do the cleanup for all specified path scopes
+ForEach ($PathScopeItem in $PathScope)
+{
+  $AssembledNewPath = $NewPath = ''
+  #From the current path scope. retrieve the array of paths that match the pathspec of PowerShell Core (to use as a filter)
+  $pathstoremove = @([Environment]::GetEnvironmentVariable("PATH","$PathScopeItem").split(';') | Where { $_ -ilike "*\Program Files\Powershell\6*"})
+  If (!$RemoveAllOccurences)
+  {
+    #If we are not removing all occurances of powershell core paths, then remove the highest sorted path from the filter
+    $pathstoremove = @($pathstoremove | sort-object | Select-Object -skiplast 1)
+  }
+  Write-Verbose "Reset-PWSHSystemPath: Found $($pathstoremove.count) paths to remove from $PathScopeItem path scope: $($Pathstoremove -join ', ' | out-string)"
+  If ($pathstoremove.count -gt 0)
+  {
+    foreach ($Path in [Environment]::GetEnvironmentVariable("PATH","$PathScopeItem").split(';'))
+    {
+      #rebuild the path in the same order, but eliminate the paths in the filter array and blanks
+      If ($Path)
+      {
+        If ($pathstoremove -inotcontains "$Path")
+        {
+          [string[]]$Newpath += "$Path"
+        }
+      }
+    }
+    $AssembledNewPath = ($newpath -join(';')).trimend(';')
+    $AssembledNewPath -split ';'
+    [Environment]::SetEnvironmentVariable("PATH",$AssembledNewPath,"$PathScopeItem")
+  }
+}