Hello Monks,

I am attempting exercise 5 in chapter 9 in the Llama 4th ed. I asks you to determine if a copyright line has been added to each file that you feed to it on the command line. If there is no copyright it is supposed to add one, while at the same time creating a backup for safe keeping.

Instead the program obliterates the contents of BOTH file and backup. Can someone help me figure out why this is happening? Here is my solution to the problem: -----------------------------

#!/usr/bin/perl -w
use strict;

$^I = ".bak";
my %do_these;
foreach (@ARGV) {
    $do_these{$_} = 1;
  }
while (<>) {
  if (/^## Copyright/) {
    delete $do_these{$ARGV};
  }
}
@ARGV = sort keys %do_these;
while (<>) {
  if (/^#!/) {
  $_ .= "## Copyright (C) 2008 by C'est mois\n";
  }
  print;
}
[download]

Thanks!