poshy-multimedia

0.4.0.0

lib/poshy-ecks.0.3.0/Remove-EnvVar.ps1

#!/usr/bin/env pwsh
$ErrorActionPreference = "Stop"
Set-StrictMode -Version Latest


# Removes matching environment variables, requires explicit specification of scope.
function Remove-EnvVar() {
    [CmdletBinding(DefaultParameterSetName = "ProcessScopeSpecificName")]
    param(
        [Parameter(Mandatory=$true, ParameterSetName="MachineScopeSpecificName", Position=0)]
        [Parameter(Mandatory=$true, ParameterSetName="MachineScopeNameLike", Position=0)]
        [switch] $Machine,

        [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeSpecificName", Position=0)]
        [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeNameLike", Position=0)]
        [switch] $Process,

        [Parameter(Mandatory=$true, ParameterSetName="UserScopeSpecificName", Position=0)]
        [Parameter(Mandatory=$true, ParameterSetName="UserScopeNameLike", Position=0)]
        [switch] $User,

        [Parameter(Mandatory=$true, ParameterSetName="ScopeValueSpecificName", Position=0)]
        [Parameter(Mandatory=$true, ParameterSetName="ScopeValueNameLike", Position=0)]
        [System.EnvironmentVariableTarget] $Scope,

        [Parameter(Mandatory=$true, ParameterSetName="MachineScopeSpecificName", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeSpecificName", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="UserScopeSpecificName", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="ScopeValueSpecificName", Position=1)]
        [ValidateLength(1, [int]::MaxValue)]
        [string] $Name,

        [Parameter(Mandatory=$true, ParameterSetName="MachineScopeNameLike", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeNameLike", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="UserScopeNameLike", Position=1)]
        [Parameter(Mandatory=$true, ParameterSetName="ScopeValueNameLike", Position=1)]
        [ValidateLength(1, [int]::MaxValue)]
        [string] $NameLike
    )
    Begin {
        if ($Machine -and $Machine.IsPresent) {
            $Scope = [System.EnvironmentVariableTarget]::Machine
        } elseif ($Process -and $Process.IsPresent) {
            $Scope = [System.EnvironmentVariableTarget]::Process
        } elseif ($User -and $User.IsPresent) {
            $Scope = [System.EnvironmentVariableTarget]::User
        }

        if (-not [System.EnvironmentVariableTarget]::IsDefined($Scope)) {
            throw "Unrecognized EnvironmentVariableTarget '$Scope'"
        }
    }
    Process {
        if ($Scope -ne [System.EnvironmentVariableTarget]::Process) {
            throw [System.NotSupportedException]::new("Removal of only Process-scoped environment variables is supported at this time.")
        }

        if ($Name) {
            Remove-Item Env:$Name
        } elseif ($NameLike) {
            Get-ChildItem Env:$NameLike | Remove-Item
        } else {
            throw [System.InvalidOperationException]::new("Either Name or NameLike must be specified.")
        }
    }
}