Ok, try this... It has the fix to the params regex, the fix to the not_method regex, I also changed around the header bit so it does a regex replace using a positive lookahead, cuz your split just didn't work quite right... 
#!c:/perl/bin/perl.exe

use strict;

use warnings;

use File::Find;

our $copyright = <<'HERE';
#region "Usage Rights"
//  Redacted to protect the guilty
//  All rights reserved.  This document was developed under U.S.
//  Government Contract No. pi, and therefore the U.S.
//  Government is granted a copyright license to this document for U.S
+.
//  Government purposes.
#endregion

HERE

our $access_modifier = "public|private|protected|internal|protected in
+ternal";
our $method_modifier = "virtual|sealed|override|abstract|extern";

our $comment = <<HERE;
\\s*///\\s*<summary>
\\s*///\\s*\\w+
\\s*///\\s*</summary>
\\s*///\\s*<param name = ".+">\\w+</param>\\s*
HERE

our $not_method =
  "as|basebreakcase|catch|checked|class|const|continue|
default|delegate|do|else|enum|event|explicit|false|finally|fixed|
for|foreach|goto|if|implicit|in|interface|is|lock|namespace|
null|object|operator|out|params|readonly|ref|return|sizeof|
stackalloc|struct|switch|this|throw|true|try|typeof|unchecked|
unsafe|using|volatile|while";

=comment
put stuff to glob the files here.
=cut

#  Gets input and output filenames while getting Wanted to work
my ($filin, $filout) = (@ARGV);

Wanted($filin, $filout);

exit;

sub Wanted {
  my ($filin, $filout) = (@_);

  my %methods;

  open(FILIN, "<", "$filin") or die $^E;

  my $autogen = 0;

  my $line;

  while ($line = <FILIN>) {
    chomp $line;
    if ($line =~ /^\W*(?:$not_method)/) {
      next;
    }
    if ($autogen < 48) {   #   This block looks for auto-generated fil
+es and skips to the next with no alterations at all.
      if ($line =~ /<auto-generated>/) {
  close FILIN;
  return 0;
      }
      ++$autogen;
    }

    if (  $line =~ m`(new)?                       # new is an optional
+ element
                     \s+ ($access_modifier)         # public, private,
+ protected etc.
                     \s* ($method_modifier)?        # static, override
+, extern, etc.  Also optional
                     \s* \w+                        # return type, not
+ optional
                     \s+ \w+                        # method name
                     \s* \( .* \)                   # parameter list i
+n parentheses
                     `xo  )                        # 'x' allows commen
+ts and internal whitespace, o says compile the pattern once only
    {
      my $method = $line;
      my $summary = $method;
      $summary =~ s/^\s+//;
      my $params = $summary;
      $params =~ s`.*\(([^\)]*)\)`$1`;
      my @params = split ',', $params;
      my $header = <<HERE;
        /// <summary>
        ///  $summary
        /// </summary>
HERE
      for (@params) {
  my ($type, $name) = split ' ', $_;
  $header .= <<HERE;
        /// <param name="$name">$type</param>
HERE
      }
      $methods{$method} = $header;
    }
  }
  close FILIN;

  open FILIN, "<", "$filin" or die $!;

  my $file;

  {local $/;
   $file = <FILIN>;
   close FILIN;
 }

 METHOD: for (sort keys %methods) {
    my $method = $_;
    if ($file =~ m`$comment$method`s) {
      next METHOD;
    }
    my $header = $methods{$method};

    $file =~ s/(?=\Q$method\E)/$header/g;
  }

  $file =~ s/#region "Usage Rights".+Government purposes.\n#endregion/
+/gs;
  $file = $copyright . $file;

  open FILOUT, ">", "$filout";
  print FILOUT $file;
  close FILOUT;
}

[download]

                - Ant
                - Some of my best work - (1 2 3)

In reply to Re^5: regex subst not DWIM by suaveant
in thread regex subst not DWIM by girarde

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