use strict;
undef $/;
my $data = <>;
my @data = split 'checking', $data;
shift @data;
my @bad_files;
for my $bit (@data) {
   my ($file_name) = $bit =~ /file <([^>]+)>/;
   push @bad_files, $file_name
      if ($bit =~ /media does not exist/);
}