open (FILE, $file);
my @file = <FILE>;
close FILE;
for (my $count = ( (scalar @file) -1); $count >= 0; $count--){
#my $line = $file[count]; optional
   # do what you gotta do

   # to end the loop abruptly, just do: $count = -1; 
   # This can be done from an else (if you are searching
   # patters with if's. 
   #Or you can use another, increasing counter, so you can
   # choose the number of lines to look at, say 12, then:
   # if ($count_2 > 12) {$count = -1}
}