{"id":1703,"date":"2018-08-24T22:00:00","date_gmt":"2018-08-24T20:00:00","guid":{"rendered":"https:\/\/demo.sidekick.be\/itenium\/environment-variables-management-with-powershell\/"},"modified":"2025-11-28T13:31:47","modified_gmt":"2025-11-28T12:31:47","slug":"environment-variables-management-with-powershell","status":"publish","type":"post","link":"https:\/\/demo.sidekick.be\/itenium\/blog\/dev-setup\/environment-variables-management-with-powershell\/","title":{"rendered":"Managing Environment Variables with PowerShell"},"content":{"rendered":"

If you\u2019d like a GUI instead you could try: <\/a>rix0rrr\/WindowsPathEditor<\/a>:<\/p>\n

Getting environment variables<\/h1>\n
# Listing all environment variables\nGet-ChildItem Env:\nenv\n\n# Or just those containing path\nGet-ChildItem Env:*PATH* | Format-List\n\n# Display a specific one (case insensitive)\n$env:PATH\n[environment]::GetEnvironmentVariable(\"PATH\", \"Process\")\n\n# They are the union of\n# Machine: HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession ManagerEnvironment\n[environment]::GetEnvironmentVariable(\"PATH\", \"Machine\")\n# User: HKEY_CURRENT_USEREnvironment\n[environment]::GetEnvironmentVariable(\"PATH\", \"User\")\n<\/code><\/pre>\n
In cmd.exe, all envs can be listed with set<\/code>.<\/p>\n
Managing environment variables<\/h1>\n
# Managing current session environment\n$env:test = \"value\"\nRemove-Item Env:test\n\n# Persistent registry management (registry)\n[Environment]::SetEnvironmentVariable(\"yaye\", \"value\", \"User\")\n[Environment]::SetEnvironmentVariable(\"yaye\", \"$null\", \"User\")\n\n# Requires RunAs Admin\n[Environment]::SetEnvironmentVariable(\"yaye\", \"value\", \"Machine\")\n<\/code><\/pre>\n
When using the PowerShell $env:key = \"val\"<\/code>, the environment changes are available only for the current session. When using the .NET [Environment]::SetEnvironmentVariable<\/code>, the changes are persisted to the registry but they do not become available in the current session.<\/p>\n
A helper function to the rescue!<\/p>\n
Set-Alias se Set-Environment\n\nfunction Set-Environment([String]$key, [String]$value) {\n\t[System.Environment]::SetEnvironmentVariable(\"$key\", \"$value\", \"User\")\n\tSet-Item -Path Env:$key -Value $value\n}\n<\/code><\/pre>\n
Already opened processes, tabs, etc won\u2019t see these environment changes. The environment can be refreshed from the registry however.<\/p>\n
Set-Alias re Refresh-Environment\n\nfunction Refresh-Environment {\n\t$locations = 'HKLM:SYSTEMCurrentControlSetControlSession ManagerEnvironment', 'HKCU:Environment'\n\t$locations | ForEach-Object {\n\t\t$k = Get-Item $_\n\t\t$k.GetValueNames() | ForEach-Object {\n\t\t\t$name = $_\n\t\t\t$value = $k.GetValue($_)\n\t\t\tSet-Item -Path Env:$name -Value $value\n\t\t}\n\t}\n\n\t# Put Machine and User $env:PATH together\n\t$machinePath = [Environment]::GetEnvironmentVariable(\"PATH\", \"Machine\")\n\t$userPath = [Environment]::GetEnvironmentVariable(\"PATH\", \"User\")\n\t$Env:PATH = \"$machinePath;$userPath\"\n}\n<\/code><\/pre>\n
If you have chocolatey installed, RefreshEnv<\/code> will also work.<\/p>\n
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$env:PATH helpers<\/h1>\n
Use fp<\/code> to list all directories in $env:path<\/code>. It accepts a search needle as parameter. ex: fp node<\/code>.<\/p>\n
By using the PowerShell builtin variable $args<\/code>, it is not required to put quotes around directories containing spaces.<\/p>\n
Set-Alias fp Find-EnvironmentPath\n\nfunction Find-EnvironmentPath {\n\t$needle = ($args -join \" \").TrimEnd(\"\")\n\t$needle = [Regex]::Escape($needle)\n\n\t$env:PATH.split(\";\") |\n\t\tWhere-Object { $_.TrimEnd(\"\") -match $needle } |\n\t\tSort-Object |\n\t\tGet-Unique -AsString\n}\n<\/code><\/pre>\n
Append a directory to the User path with ap c:bins<\/code>.<\/p>\n
Set-Alias ap Append-EnvironmentPath\n\nfunction Append-EnvironmentPath {\n\t$toAppend = ($args -join \" \").TrimEnd(\"\")\n\tif (-not (Test-Path $toAppend)) {\n\t\tWrite-Host \"Path doesn't exist...\"\n\t\tWrite-Host $toAppend\n\t\treturn\n\t}\n\t$env:PATH = $env:PATH + \";$toAppend\"\n\t$userPath = [Environment]::GetEnvironmentVariable(\"PATH\", \"User\")\n\t[Environment]::SetEnvironmentVariable(\"PATH\", \"$userPath;$toAppend\", \"User\")\n}\n<\/code><\/pre>\n
Remove a directory from the User path with delp c:Program FilessomeBin<\/code>.<\/p>\n
Set-Alias delp Remove-EnvironmentPath\n\nfunction Remove-EnvironmentPath {\n\t$toRemove = ($args -join \" \").TrimEnd(\"\")\n\n\t$userPath = [Environment]::GetEnvironmentVariable(\"PATH\", \"User\")\n\t$changedUserPath = $userPath.Split(\";\") |\n\t\tForEach-Object { $_.TrimEnd(\"\") } |\n\t\tWhere-Object { $_ -ne $toRemove }\n\n\t$changedUserPath = $changedUserPath -Join \";\"\n\n\tif ($userPath -ne $changedUserPath) {\n\t\t[Environment]::SetEnvironmentVariable(\"PATH\", \"$changedUserPath\", \"User\")\n\t\t$env:PATH = [Environment]::GetEnvironmentVariable(\"PATH\", \"Machine\")\n\t\t$env:PATH += \";$changedUserPath\"\n\t\treturn\n\t}\n\n\techo \"Not removed\"\n\n\t$machinePath = [Environment]::GetEnvironmentVariable(\"PATH\", \"Machine\")\n\t$isInMachine = $machinePath.split(\";\") | Where-Object { $_.Trim(\"\") -eq $toRemove }\n\tif ($isInMachine) {\n\t\techo \"Is present in Machine scope\"\n\t}\n}\n<\/code><\/pre>\n
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Useful environment variables<\/h1>\n
Win + Pause: Control PanelSystem and SecuritySystem<\/code>
 PowerShell: $env:USERNAME<\/code>
 Cmd: %USERNAME%<\/code><\/p>\n
These are probably worth remembering.<\/p>\n
\"$env:USERNAME@$env:USERDOMAIN\"\n\n$env:APPDATA\n# C:UsersWouterAppDataRoaming\n\n$env:HOME\n$env:USERPROFILE\n# C:UsersWouter\n\n$env:LOCALAPPDATA\n# C:UsersWouterAppDataLocal\n\n$env:TEMP\n# C:UsersWouterAppDataLocalTemp\n<\/code><\/pre>\n
Extras<\/h1>\n
Stuff that came into being during the making of this post<\/b><\/p>\n