use File::ReadBackwards;
tie *BW, 'File::ReadBackwards', 'log_file' or
    die "can't read 'log_file' $!" ;

while( <BW> ) {
    print ;
}

##</code><code>##

use Tie::File;
tie my @array, 'Tie::File', 'log_file' or 
    die "can't read 'log_file' $!";
for ( 1 .. @array ) {
    $_ = -$_;
    print $array[$_];
}