53 lines
2.3 KiB
PowerShell
53 lines
2.3 KiB
PowerShell
# Capture environment variables for the System and User. Also add some special/built-in variables.
|
|
# These will be used to synthesize a clean environment
|
|
$specialEnvironmentMap = @{ "SystemDrive"=$env:SystemDrive; "SystemRoot"=$env:SystemRoot; "UserProfile"=$env:UserProfile; "TMP"=$env:TMP } # These are built-in and not set in the registry
|
|
$machineEnvironmentMap = [Environment]::GetEnvironmentVariables('Machine') # HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment
|
|
$userEnvironmentMap = [Environment]::GetEnvironmentVariables('User') # HKEY_CURRENT_USER\Environment
|
|
|
|
# Identify the keySet of environment variable names
|
|
$nameSet = ($specialEnvironmentMap.Keys + $machineEnvironmentMap.Keys + $userEnvironmentMap.Keys) | Sort-Object | Select-Object -Unique
|
|
|
|
# Any environment variable in the $nameSet should be restored to its original value
|
|
foreach ($name in $nameSet)
|
|
{
|
|
if ($specialEnvironmentMap.ContainsKey($name))
|
|
{
|
|
[Environment]::SetEnvironmentVariable($name, $specialEnvironmentMap[$name], 'Process')
|
|
continue;
|
|
}
|
|
|
|
# PATH needs to be concatenated as it has values in both machine and user environment. Any other values should be set.
|
|
if ($name -eq 'path')
|
|
{
|
|
$pathValuePartial = @()
|
|
# Machine values before user values
|
|
$pathValuePartial += $machineEnvironmentMap[$name] -split ';'
|
|
$pathValuePartial += $userEnvironmentMap[$name] -split ';'
|
|
$pathValue = $pathValuePartial -join ';'
|
|
[Environment]::SetEnvironmentVariable($name, $pathValue, 'Process')
|
|
continue;
|
|
}
|
|
|
|
if ($userEnvironmentMap.ContainsKey($name))
|
|
{
|
|
[Environment]::SetEnvironmentVariable($name, $userEnvironmentMap[$name], 'Process')
|
|
continue;
|
|
}
|
|
|
|
if ($machineEnvironmentMap.ContainsKey($name))
|
|
{
|
|
[Environment]::SetEnvironmentVariable($name, $machineEnvironmentMap[$name], 'Process')
|
|
continue;
|
|
}
|
|
|
|
throw "Unreachable: Unknown variable $name"
|
|
}
|
|
|
|
# Any environment variable NOT in the $nameSet should be removed
|
|
$processEnvironmentMap = [Environment]::GetEnvironmentVariables('Process')
|
|
$variablesForRemoval = $processEnvironmentMap.Keys | Where-Object {$nameSet -notcontains $_}
|
|
foreach ($name in $variablesForRemoval)
|
|
{
|
|
[Environment]::SetEnvironmentVariable($name, $null, 'Process')
|
|
}
|