PowerShell: module for the PATH system environment variable

pwsh-EnvPaths.psm1

# PowerShell Module File
# Name: EnvPaths.psm1
# Desc: Module for handling of the 'Path' system environment variable
# Source: https://gist.github.com/Hrxn/57c83ab93d642bdd868f97355f3aab45; Based on: https://gist.github.com/mkropat/c1226e0cc2ca941b23a9

function Get-EnvPath {
	param(
		[Parameter()]
		[ValidateSet('Machine', 'User', 'Session')]
		[string] $Container = 'Session'
	)

	$ContainerMapping = @{
		Machine = [System.EnvironmentVariableTarget]::Machine
		User = [System.EnvironmentVariableTarget]::User
	}
	$ContainerType = $ContainerMapping[$Container]

	switch ($Container) {
		'Session' {
			$Env:Path -split [System.IO.Path]::PathSeparator | Where-Object { $_ }
		}
		default {
			[System.Environment]::GetEnvironmentVariable('Path', $ContainerType) -split [System.IO.Path]::PathSeparator | Where-Object { $_ }
		}
	}
}

function Add-EnvPath {
	param(
		[Parameter(Mandatory)]
		[ValidateNotNullOrWhiteSpace()]
		[string] $Path,

		[ValidateSet('Machine', 'User', 'Session')]
		[string] $Container = 'Session'
	)

	if ($Container -ne 'Session') {
		$ContainerMapping = @{
			Machine = [System.EnvironmentVariableTarget]::Machine
			User = [System.EnvironmentVariableTarget]::User
		}
		$ContainerType = $ContainerMapping[$Container]

		$PersistedPaths = [System.Environment]::GetEnvironmentVariable('Path', $ContainerType) -split [System.IO.Path]::PathSeparator
		if ($PersistedPaths -notcontains $Path) {
			$PersistedPaths = $PersistedPaths + $Path | Where-Object { $_ }
			[System.Environment]::SetEnvironmentVariable('Path', $PersistedPaths -join [System.IO.Path]::PathSeparator, $ContainerType)
		}
	}

	$EnvPaths = $Env:Path -split [System.IO.Path]::PathSeparator
	if ($EnvPaths -notcontains $Path) {
		$EnvPaths = $EnvPaths + $Path | Where-Object { $_ }
		$Env:Path = $EnvPaths -join [System.IO.Path]::PathSeparator
	}
}

function Remove-EnvPath {
	param(
		[Parameter(Mandatory)]
		[ValidateNotNullOrWhiteSpace()]
		[string] $Path,

		[ValidateSet('Machine', 'User', 'Session')]
		[string] $Container = 'Session'
	)

	if ($Container -ne 'Session') {
		$ContainerMapping = @{
			Machine = [System.EnvironmentVariableTarget]::Machine
			User = [System.EnvironmentVariableTarget]::User
		}
		$ContainerType = $ContainerMapping[$Container]

		$PersistedPaths = [System.Environment]::GetEnvironmentVariable('Path', $ContainerType) -split [System.IO.Path]::PathSeparator
		if ($PersistedPaths -contains $Path) {
			$PersistedPaths = $PersistedPaths | Where-Object { $_ -and $_ -ne $Path }
			[System.Environment]::SetEnvironmentVariable('Path', $PersistedPaths -join [System.IO.Path]::PathSeparator, $ContainerType)
		}
	}

	$EnvPaths = $Env:Path -split [System.IO.Path]::PathSeparator
	if ($EnvPaths -contains $Path) {
		$EnvPaths = $EnvPaths | Where-Object { $_ -and $_ -ne $Path }
		$Env:Path = $EnvPaths -join [System.IO.Path]::PathSeparator
	}
}

# [Section] Exporting Module Content
Export-ModuleMember -Function Get-EnvPath, Add-EnvPath, Remove-EnvPath