Is the most recent the last line in the file, like your sample data. If so, you could try File::ReadBackwards and only read and print the last line of the file & exit.

use File::ReadBackwards ;
    # Object interface
    $bw = File::ReadBackwards->new( 'log_file' ) or
                        die "can't read 'log_file' $!" ;
    while( defined( $log_line = $bw->readline ) ) {
            print $log_line ;
            last; # Only print the last line
    }
[download]

HTH,

Chris