Is it possible to include function reference in scripblock{}?

PowerShell Help
1

Hello,

Is it possible to do something like below?

function a {
write-output "AAA"
}

[scriptblock] $b = {
a
}
2

Yep, thatā€™s fine. The only difference between a function and a script block assigned to a variable like that is the name. :slight_smile:

3

This does not work though. How do I calla function a in scriptblock?

4

Works fine for me. Keep in mind that in your example code, you havenā€™t actually executed the script block thatā€™s assigned to the $b variable. If you add this statement after your code, you execute $b, which calls ā€œaā€:

& $b
5

Can you give a real example of why you would do this?

6

I need to include function in scriptblock and then use tis scripblock as a parameter to third party cmdlet (namely Invoke-Parallel). So far I did not figure out how to do that except for pasting entire function to into scriptblock before passing it to cmdlet.

7

Ah. That would depend on what Invoke-Parallel is doing with that object once you pass it in. Itā€™s probably running it in a separate runspace, where your other function doesnā€™t exist.

8

Yes, thatā€™s what is being used (GitHub - RamblingCookieMonster/Invoke-Parallel: Speed up PowerShell with simplified multithreading).
So I assume I have to hardcode everything into [scriptblock] for this to work.

9

$.02 While Boe is as smart as they come in the PS arena and his scripts are intriguingā€¦I donā€™t think all this runspace stuff is even necessary. If you do, you need to relax your schedule a bit. The box of pop-tarts says to microwave for three secondsā€¦I donā€™t have that kinda time :smiley:

Pass your script block to the function as a parameter.

$b = {$env:computername}

function a
{
param($scriptblock)

&$scriptblock

}

a $b

Powershell is not meant to be complicated.

10

this code works.
Is is not plain function using but not including full function text :slight_smile:

PS C:\> function aaa($msg) { Write-Host ('FUNC says '+$msg+" to You") }
PS C:\> $sb1 = [scriptblock]::Create( "function aaa { $function:aaa }; aaa įæÆ$_ " )
PS C:\> 1..10 | invoke-parallel -scriptblock $sb1
FUNC says 1 to You
FUNC says 2 to You
FUNC says 3 to You
FUNC says 4 to You
FUNC says 5 to You
FUNC says 6 to You
FUNC says 7 to You
FUNC says 8 to You
FUNC says 9 to You
FUNC says 10 to You
1 Like
11

What 

 $function:aaa
inside scriptblock means?

Greg

1 Like
12

you can see it yourself :slight_smile:
just type

PS C:> function aaa($msg) { Write-Host ('FUNC says '+$msg+" to You") }
PS C:> $function:aaa

itā€™s redefinition of your outside function (aaa) in a scriptblock :slight_smile:
I use $function namespace just like variables $global namespace instead of code typing, bracket matching and so on.

Technically You get ā€œpasting entire function to into scriptblock before passing it to cmdletā€ but without pasting :slight_smile:

1 Like
13

Š”ŠæŠ°ŃŠøŠ±Š¾. Š’ŠµŠŗ Š¶ŠøŠ²Šø, Š²ŠµŠŗ учŠøсь.