Dot Source a “script” within a Function

My PowerShell profile is getting a bit cumbersome and I find that I don't always use everything in it. I want to reduce the size of my profile and speed up the startup time that's been getting slower and slower, but I still want to be able to access those functions relatively quickly when I need them.

Is there a way to "Dot Source" a set of PowerShell Functions and Aliases from within a separate function such that the sourced functions will be available outside of that function call?

回答1:

As others have already pointed out, the proper way to go about this would be to put those extra functions into a module. In its simplest form a module is a subfolder in one of the folders listed in $env:PSModulePath with a PowerShell script of the same name (but with the extension .psm1 instead of .ps1):

$env:USERPROFILE
`-Documents
  `-WindowsPowerShell
    `-Modules
      `-ExtraFunctions
        `-ExtraFunctions.psm1

ExtraFunctions.psm1 contains all your functions and ends with an Export-ModuleMember statement exporting the functions/aliases/… you want to publish:

function Get-Foo {
  ...
}

function New-Bar {
  ...
}

...

New-Alias -Name gf -Value Get-Foo
...

Export-ModuleMember -Function Get-Foo, New-Bar, ... -Alias gf, ...

That way you can import specific members:

PS C:\> Import-Module ExtraFunctions -Function Get-Foo

or everything at once:

PS C:\> Import-Module ExtraFunctions

A module can be unloaded via the Remove-Module cmdlet:

PS C:\> Remove-Module ExtraFunctions

With PowerShell v3 and newer you don't even need to import your module manually, because modules are loaded automatically when one of their exported functions/cmdlets is called.

If you want to put in some extra work you can add a module manifest:

@{
  # Script module or binary module file associated with this manifest
  ModuleToProcess = 'ExtraFunctions.psm1'

  # Version number of this module.
  ModuleVersion = '1.0'

  # ID used to uniquely identify this module
  GUID = 'dbf5a7ca-683a-4f18-a090-0700ecccf6ff'

  # Author of this module
  Author = 'Ansgar Wiechers'

  # Company or vendor of this module
  CompanyName = ''

  # Copyright statement for this module
  Copyright = ''

  # Description of the functionality provided by this module
  Description = 'Extra functions.'

  # Minimum version of the Windows PowerShell engine required by this module
  PowerShellVersion = ''

  # Name of the Windows PowerShell host required by this module
  PowerShellHostName = ''

  # Minimum version of the Windows PowerShell host required by this module
  PowerShellHostVersion = ''

  # Minimum version of the .NET Framework required by this module
  DotNetFrameworkVersion = ''

  # Minimum version of the common language runtime (CLR) required by this
  # module
  CLRVersion = ''

  # Processor architecture (None, X86, Amd64, IA64) required by this module
  ProcessorArchitecture = ''

  # Modules that must be imported into the global environment prior to
  # importing this module
  RequiredModules = @()

  # Assemblies that must be loaded prior to importing this module
  RequiredAssemblies = @()

  # Script files (.ps1) that are run in the caller's environment prior to
  # importing this module
  ScriptsToProcess = @()

  # Type files (.ps1xml) to be loaded when importing this module
  TypesToProcess = @()

  # Format files (.ps1xml) to be loaded when importing this module
  FormatsToProcess = @()

  # Modules to import as nested modules of the module specified in
  # ModuleToProcess
  NestedModules = @()

  # Functions to export from this module
  FunctionsToExport = 'Get-Foo', 'New-Bar'

  # Cmdlets to export from this module
  CmdletsToExport = ''

  # Variables to export from this module
  VariablesToExport = ''

  # Aliases to export from this module
  AliasesToExport = 'gf'

  # List of all modules packaged with this module
  ModuleList = @()

  # List of all files packaged with this module
  FileList = 'ExtraFunctions.psm1'

  # Private data to pass to the module specified in ModuleToProcess
  PrivateData = ''
}

Manifests allow you for instance to define dependencies, or to split your module implementation into multiple files. They can be created manually or via the New-ModuleManifest cmdlet. Put the manifest into the root folder of the module:

$env:USERPROFILE
`-Documents
  `-WindowsPowerShell
    `-Modules
      `-ExtraFunctions
        +-ExtraFunctions.psd1
        `-ExtraFunctions.psm1

回答2:

After a great deal of effort (and to make sure I won't lose it later), here's what I've found works.

I've placed the following function in my profile:

function extras {. C:\...\WindowsPowerShell\extrafunctions.ps1}

And then I "Dot Source" the function within the PowerShell window.

. extras

and all my extra functions are available to the session without slowing down the startup time.