Question

I’m trying to find a function in a few hundred pages and remove it using Powershell. I can match on a single line but I’m having issues getting a multi-line match to work. Any help would be appreciated.

Function I’m trying to find:

Protected Function MyFunction(ByVal ID As Integer) As Boolean
    Return list.IsMyFunction()  
End Function

Code I’m using that won’t match multi-line:

gci -recurse | ?{$_.Name -match "(?i)MyPage.*\.aspx"} | %{
  $c = gc $_.FullName;
  if ($c -match "(?m)Protected Function MyFunction\(ByVal ID As Integer\) As Boolean.*End Function")  {
    $_.Fullname | write-host;
  }
}

Answer 1

You can use the (?s) flag on the regex. S for singleline, also called, dotall in some places, which makes . match across newlines.

Also, gc reads line by line and any comparision / match will be between individual lines and the regex. You will not get a match despite using proper flags on the regex. I usually use [System.IO.File]::ReadAllText() to get the entire file’s contents as a single string.

So a working solution will be something like:

gci -recurse | ?{$_.Name -match "(?i)MyPage.*\.aspx"} | %{
  $c = [System.IO.File]::ReadAllText($_.Fullname)
  if ($c -match "(?s)Protected Function MyFunction\(ByVal ID As Integer\) As Boolean.*End Function")  {
    $_.Fullname | write-host;
  }

}

For the replace, you can of course use $matches[0] and use the Replace() method

$newc = $c.Replace($matches[0],"")