How to search .token files in a folder and replace "__" in front and end of character via Powershell?

Question

I would like to search thru files with .token files that have a string with the following pattern __[characters]__ and perform the following via PowerShell:

• remove "__" (two underscores) in front of any character with an "#{"
• remove "__" (two underscores) at the end of the same character and replace with "}"

For example:

__STAGE__
to
#{STAGE}

I am migrating RM token files to Octopus Deploy and need a clean up step via scripting.

Answer 1

In the most basic way and assuming there's no problem fitting a token file into memory:

$TokenFiles = Get-ChildItem *.token

foreach ($file in $TokenFiles) {
    $NewContent = Get-Content $file.FullName -Raw
    $NewContent = $NewContent -replace '__(.*?)__', '#{$1}'
    Set-Content $file.FullName -Value $NewContent
}