my %month = (
        Jan => 0,
        Feb => 1,
        ...
);

# ...

$month = $month{$month};  # Could stand to use better names
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open(LOGFILE, "datafile.html") || die "Can't open file";

foreach my $log_line (<LOGFILE>)
{
     # ...
}
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my $hour = param ("hour");
my $minute = param ("minute");
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Alternately, you could build a month => month_num hash with a one-line map statement ala:

my %months = map { (qw/Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
+/)[$_] => $_}(0..11);
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I like doing stuff like this because it saves you the possible typo(s) if you userstand how map works. I'm always looking for more efficient ways to do it, however. Can anyone think of any?

    --jb

Why use an array and map and a hash. A string and index will do it.

my $month_num = index( 'Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov De
+c', $month_str)/4;
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---

Examine what is said, not who speaks.

Thanks, I totally missed the error problem, thanks for pointing it out. Would going through the log one line at a time be more efficient?

If you have a 2GB log file, you can imagine that reading the whole thing into memory isn't going to be terribly efficient. Processing it one line at a time is virtually a must.

Unless you need to read in the whole file because it's not terribly large and you will be refering to it several times, it is almost always better to pick through it one line at a time.

BrowserUk, I decided against using Date:Manip even though I really like that module. That's because the module instructions warn that it's slower than other time modules and this script will be used most often when the web server is overloaded with requests; thus, speed is essential.

Given you are doing a filesystem read between every call to Date::Manip, I seriously doubt it would be a bottleneck. In any case it would be running faster than your broken code:).

If you really find that Date::Manip is too slow for your application, then you could move to using one of the (several dozen) Date::* modules on CPAN rather than attempting to roll your own. Several of these are mentioned in the Date::Manip pod: Date::Parser, Date::Calc. The later of which is an interface to a C library I believe and its reputedly very fast. The main reason I didn't suggest these is that you need to compile them which is sometimes a problem.

A quick look at your code and its glaringly obvious what the problem is. And if you hadn't commented out the use strict and omitted the -w/use warnings it would be glaringly obvious to you too, as the compiler would be screaming the cause at you over and over. 11 times I think.

Come back, if you need to, once you have made your code compile cleanly with -w and use strict and you might get some further help.

I'm really sorry if I offended you. That wasn't my intention at all and I really appreciate the help. I was reluctant to install Date::Manip, being new to this stuff, but I've done it and now I'm trying to figure out where to specify the log files on my server to test your code. Again, thanks and I didn't mean to offend you.

• For the switch, use eq instead of ==. == operator is for comparing numbers, and eq is for comparing strings. Also better use a hash, instead of this switch, that makes your code more neat. Key for the hash would be 'Jan' etc, and value would be 0 etc.
• For question 3, instead of array, use hash. The key for the hash is referer, and value is the counter.

Thanks, eq works. Using == was a real newbie miss. I couldn't quite figure out how to use the hash.

• Tight deadline
• Performance
• Working code

Now, a few of these don't match. Even more don't add up when you add priorities that you *should* have, notably "secure".

So, lets detail some of the issues we have with the code thus far:

• Reading in entire log file (into ram no less) every time the script is run
• No use of taint mode
• No use of warnings
• Bad choice of time comparison algorithm
• Iffy regexen

Under these circumstances, without access to help, you should be getting your priorities in order. While it depends on your particular position, the following is a good start:

1. Working code
2. Working, secure code
3. Working, secure code by deadline
4. Working, secure, maintainable code by deadline
5. Working, secure, maintainable code that performs well, by deadline

What does this mean? Well, the first thing it means is that if a well known, already-debugged module is around that can do any part of the problem you're trying to solve, use it. Performance is waaay down on the list, just use it. If it really turns out too slow in use, *then* you worry about it.

The second thing it means is a quick investigation of language features that can help you out with debugging and security. Taint mode, Strict and Warnings should all be on, and you shouldn't move an inch until your code is working with all of them.

Now, if you had done this, most of the code above, that isn't working, wouldn't even exist. You'd have something a fraction of the size, that worked fine. Maybe it'd be a bit slow, maybe not, but if it was, you'd be posting to perlmonks saying "Hey, here's my working code, how can I make it go a bit faster", and then people like Abigail-II would have been able to tell you how exactly a database would aid your cause, even when the logs are in text file format. But we're not there yet.

#!/usr/bin/perl -t
use strict;
use warnings;
use Date::Manip;
use CGI qw/:standard/;

# Make sure neither we, nor any of our submodules compromise security
# by calling unpathed programs.
$ENV{PATH} = "/bin:/usr/bin";
$ENV{IFS}="";

# Use CGI to print our headers
print header;

my %referers = ();

# Retrieve and security-check parameters
my $hour = param('hour');
my $minute = param('minute');

if ($hour !~ /^\d\d?$/) { die('Invalid hour'); }
if ($minute !~ /^\d\d?$/) { die('Invalid minute'); }

# Get date object for our check point
my $check_date = ParseDate("${hour}hours ${minute}minutes ago");

# File handling, one line at a time
open(FH,"file") || die('Could not open log file');
while (my $line = <FH>) {

    next if ($line !~ /^\S+ \S \S (\S+) \S+ "[^"]+" \d+ \d+ "([^"]+)"/
+);
    
    my $line_date = ParseDate($1);

    # Check to see if the line date is in the range we're after
    next unless Date_Cmp($line_date, $check_date)>0;

    # If the referer is new, we set to 1 entry, otherwise increment (i
+ncrementing undef doesn't work well)
    if (!$referers{$2}) {
        $referers{$2}=1;
    } else {
        $referers{$2}++;
    }
}
close(FH);

my $row = 0;

# Sort our referers by the number of hits
for (sort {$referers{$b} <=> $referers{$a}} keys %referers) {
    # break out after the tenth one
    last if $row++==10;
    print "$_: ".$referers{$_}."\n";
}
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This is by no means perfect, I didn't have enough log examples to work from to be sure the regex will work well, but it contains all the properties of a good first effort. All the necessary warnings and taints turned on, the relevant modules used (there is, I think, an apache log parsing module too, but I wasn't sure you were using apache), all user input is verified and no more code than strictly necessary is used.

The end result...no weird month name/number conversions, about 30 seconds of debugging, and a much better product. I highly recommend, prior to your next project, sitting down and listing your priorities as above, it will help focus you on what really matters first, and what can be tweaked second.

I note that my regex is not entirely correct, my cut&paste of the logs that I used for testing did not contain the square brackets, not sure how that happened, regex should be:

/^\S+ \S \S \[(\S+) \S+\] "[^"]+" \d+ \d+ "([^"]+)"/
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I believe

Thanks. I've installed Date::Manip and tried to run your code as a test, but I keep getting "Premature end of script headers" errors. I've checked the path on my server but can't figure out why it's generating these errors. Can you tell me why? Thanks.

As a hunch, you may need to try switching off taint (the -t switch). Date::Manip may not be handling taint correctly, other than that, no reason that I can think of.

It's a problem with the output of the script; which is more than likely quite easy to fix. You print your headers using a call to CGI.pm (see the print header; line?), followed by a blank line, and then the page data (<html> etc.).

You get the "premature end of script headers error" if you didn't output the blank line. That means your problem may be something to do with your print header; line.

Try reading the CGI spec, the CGI.pm perldoc , and try again.

rdfield

Oh, my. I didn't mean to offend Abigail-II or anyone else, for that matter. I admit to being a total newcomer to both Perl and this list and I really appreciate the help being offered. I apologize deeply if I've been offensive!