src/Get-EnvVar.ps1
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#!/usr/bin/env pwsh $ErrorActionPreference = "Stop" Set-StrictMode -Version Latest <# .SYNOPSIS Gets the names and values of environment variables at a given environment variable scope. .PARAMETER Process Restricts the results to environment variables at the Process-level environment variable scope. .PARAMETER User Restricts the results to environment variables at the User-level environment variable scope. .PARAMETER Machine Restricts the results to environment variables at the Machine-level environment variable scope. .PARAMETER Scope Restricts the results to environment variables at the specified environment variable scope. .PARAMETER Name Restricts the results to environment variables with the exact specified name. .PARAMETER NameLike Restricts the results to environment variables with names that match the specified wildcard pattern. .PARAMETER NameMatch Restricts the results to environment variables with names that match the specified regular expression pattern. .PARAMETER ValueOnly Indicates that this cmdlet gets only the value of the variable(s). .EXAMPLE Get-EnvVar -Process -Name "PATH" .OUTPUTS System.Collections.DictionaryEntry string .COMPONENT env #> function Get-EnvVar() { [CmdletBinding(DefaultParameterSetName = "ProcessScopeSpecificName")] param( [Parameter(Mandatory=$true, ParameterSetName="MachineScopeAnyName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="MachineScopeSpecificName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="MachineScopeNameLike", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="MachineScopeNameMatch", Position=0)] [switch] $Machine, [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeAnyName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeSpecificName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeNameLike", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeNameMatch", Position=0)] [switch] $Process, [Parameter(Mandatory=$true, ParameterSetName="UserScopeAnyName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="UserScopeSpecificName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="UserScopeNameLike", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="UserScopeNameMatch", Position=0)] [switch] $User, [Parameter(Mandatory=$true, ParameterSetName="ScopeValueAnyName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ScopeValueSpecificName", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ScopeValueNameLike", Position=0)] [Parameter(Mandatory=$true, ParameterSetName="ScopeValueNameMatch", Position=0)] [System.EnvironmentVariableTarget] $Scope, [Parameter(Mandatory=$false, ParameterSetName="MachineScopeSpecificName", Position=1)] [Parameter(Mandatory=$false, ParameterSetName="ProcessScopeSpecificName", Position=1)] [Parameter(Mandatory=$false, ParameterSetName="UserScopeSpecificName", Position=1)] [Parameter(Mandatory=$false, ParameterSetName="ScopeValueSpecificName", Position=1)] [ValidateNotNullOrEmpty()] [string] $Name = $null, [Parameter(Mandatory=$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)] [ValidateNotNullOrEmpty()] [string] $NameLike, [Parameter(Mandatory=$true, ParameterSetName="MachineScopeNameMatch", Position=1)] [Parameter(Mandatory=$true, ParameterSetName="ProcessScopeNameMatch", Position=1)] [Parameter(Mandatory=$true, ParameterSetName="UserScopeNameMatch", Position=1)] [Parameter(Mandatory=$true, ParameterSetName="ScopeValueNameMatch", Position=1)] [ValidateNotNullOrEmpty()] [string] $NameMatch, [Parameter(Mandatory=$false, Position=2)] [Alias("Value")] [switch] $ValueOnly ) Begin { if ($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 '$Scope'" } } Process { if ($Name) { [string] $valueFound = [System.Environment]::GetEnvironmentVariable($Name, $Scope) if ($null -eq $valueFound) { if ($ValueOnly -and $ValueOnly.IsPresent) { Write-Output $null } else { # Intentionally left blank. } } else { if ($ValueOnly -and $ValueOnly.IsPresent) { Write-Output $valueFound } else { [System.Collections.DictionaryEntry] $de = [System.Collections.DictionaryEntry]::new($Name, $valueFound) Write-Output $de } } } else { [System.Collections.DictionaryEntry[]] $allEnvItems = Get-ChildItem Env: foreach ($de in $allEnvItems) { if ($NameLike -and ($de.Name -notlike $NameLike)) { continue } if ($NameMatch -and ($de.Name -notmatch $NameMatch)) { continue } if ($null -eq [System.Environment]::GetEnvironmentVariable($de.Name, $Scope)) { continue } else { if ($ValueOnly) { Write-Output $de.Value } else { Write-Output $de } } } } } } |