I took the question to refer to a web diary of sorts and not the apahce web server logs. I would suggest using seperate files for each entry and use a counter file to sequentially number your entries and use that number as part of the filename. I recmommend that you start at 100000 for the counter file, then you can easily search for filenames that contain 6 digits in the future. It will be safe to slurp the smaller files as needed and it is easy to pull from one point to the next with this:

# set our variable to store the logs in
my $weblog_data;

# set the default for the number of entries per page
my $number_entries = 10; # this could be dynamic with changes

# starting point for entries
my $starting_point = '100123';
# need to be pulled
foreach ($starting_point..$starting_point_for_entries+$number_entries)
+ {
    if (-e "$_.wl") {
    open(WEBLOG,"$_.wl") or warn $!;
    while (<WEBLOG>) {
        $weblog_data .= $_;
    }
        $weblog_data = "<br>";
    }
}
[download]

That is just an example of how to loop through to get them but the code is far from complete. Using the number method will make your next and previous links easier to create as well. For me working with several files in this manner is easier then working with one long file.