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powershellself-modifying

Is it possible to write self-modifying PowerShell scripts?

Is it possible to write self-modifying PowerShell scripts?

Suppose I have a script named foo.ps1:

"Write-Host `"Goodbye world`"" | Set-Content "foo.ps1"
Write-Host "Hello world"

This script prints out Hello world. What techniques could I use to get it to print out Goodbye world?

Solution

  • To me it does not make sense, after you have modified a script, you need to re-dotsource it in order to get new statments.

    This script changes itself three times:

    Write-Host "Hello world"
"Write-Host `"Goodbye world`"" | Set-Content "foo.ps1"
. .\foo.ps1
"Write-Host `"Is really useful?`"" | Set-Content "foo.ps1"
. .\foo.ps1

    and prints:

    Hello World
Goodbye World
Is really useful?

    Another possibility is to write a script which accepts as input parameters script blocks.