use strict;
use warnings;

{
   my @filenames = ...;
   my $fn_out    = ...;

   open(my $fh_out, '>', $fn_out)
      or die("Unable to create file \"$fn_out\": $!\n");

   my $last;
   foreach my $file (@filenames) {
      my ($this) = $file =~ m{/(bakery|fruitjunction)/};
      if (!defined($last)) {
         print $fh_out ("# ", uc($this), "\n");
      }
      elsif ($last ne $this) {
         print $fh_out ("# END ", uc($last), "\n");
         print $fh_out ("# ",     uc($this), "\n");
      }
      $last = $this;
      print $fh_out ($file, "\n");
   }

   if (defined($last)) {
      print $fh_out ("# END ", uc($last), "\n");
   }
}
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