There are many different traffic analysis tools, ranging from
simple counters to complete traffic analyzers. Although there
are some free ones, most of them come with a price tag. Why not
do it yourself? With PHP, you can easily create a log file
within minutes. In this article I will show you how!
Getting the information The most important part
is getting the information from your visitor. Thankfully, this
is extremely easy to do in PHP (or any other scripting language
for that matter). PHP has a special global variable called
$_SERVER which contains several environment variables, including
information about your visitor. To get all the information you
want, simply use the following code: // Getting the
information $ipaddress = $_SERVER['REMOTE_ADDR']; $page =
"http://{$_SERVER['HTTP_HOST']}{$_SERVER['PHP_SELF']}"; $page .=
iif(!empty($_SERVER['QUERY_STRING']),
"?{$_SERVER['QUERY_STRING']}", ""); $referrer =
$_SERVER['HTTP_REFERER']; $datetime = mktime(); $useragent =
$_SERVER['HTTP_USER_AGENT']; $remotehost =
@getHostByAddr($ipaddress);
As you can see the majority
of information comes from the $_SERVER variable. The mktime()
(http://nl2.php.net/mktime) and getHostByAddr()
(http://nl2.php.net/manual/en/function.gethostbyaddr.php)
functions are used to get additional information about the
visitor.
Note: I used a function in the above example called iif(). You
can get this function at http://www.phpit.ne
t/code/iif-function.
Logging the information Now that you have all
the information you need, it must be written to a log file so
you can later look at it, and create useful graphs and charts.
To do this you need a few simple PHP function, like fopen
(http://www.php.net/fopen) and fwrite
(http://www.php.net/fwrite).
The below code will first create a complete line out of all the
information. Then it will open the log file in "Append" mode,
and if it doesn't exist yet, create it.
If no errors have occurred, it will write the new logline to the
log file, at the bottom, and finally close the log file again.
// Create log line $logline = $ipaddress . '|' . $referrer
. '|' . $datetime . '|' . $useragent . '|' . $remotehost . '|' .
$page . " ";
// Write to log file: $logfile =
'/some/path/to/your/logfile.txt';
// Open the log file in "Append" mode if (!$handle =
fopen($logfile, 'a+')) { die("Failed to open log file"); }
// Write $logline to our logfile. if (fwrite($handle, $logline)
=== FALSE) { die("Failed to write to log file"); }
fclose($handle);
Now you've got a fully function logging
module. To start tracking visitors on your website simply
include the logging module into your pages with the include()
function (http://www.php.net/include): include
('log.php');
Okay, now I want to view my log
file After a while you'll probably want to view your
log file. You can easily do so by simply using a standard text
editor (like Notepad on Windows) to open the log file, but this
is far from desired, because it's in a hard-to-read format.
Let's use PHP to generate useful overviews for is. The first
thing that needs to be done is get the contents from the log
file in a variable, like so: // Open log file $logfile =
"G:projectsphpitcontentrack your visitors using phplog.txt";
if (file_exists($logfile)) {
$handle = fopen($logfile, "r"); $log = fread($handle,
filesize($logfile)); fclose($handle); } else { die ("The log
file doesn't exist!"); }
Now that the log file is in a
variable, it's best if each logline is in a separate variable.
We can do this using the explode() function
(http://www.php.net/explode), like so: // Seperate each
logline $log = explode(" ", trim($log));
After that it
may be useful to get each part of each logline in a separate
variable. This can be done by looping through each logline, and
using explode again: // Seperate each part in each logline
for ($i = 0; $i < count($log); $i++) { $log[$i] =
trim($log[$i]); $log[$i] = explode('|', $log[$i]); }
Now the complete log file has been parsed, and we're ready to
start generating some interesting stuff.
The first thing that is very easy to do is getting the number of
pageviews. Simply use count() (http://www.phpit.net/count) on
the $log array, and there you have it; echo count($log) .
" people have visited this website.";
You can also
generate a complete overview of your log file, using a simple
foreach loop and tables. For example: // Show a table of
the logfile echo '<table>'; echo '<th>IP
Address</th>'; echo '<th>Referrer</th>'; echo
'<th>Date</th>'; echo
'<th>Useragent</th>'; echo '<th>Remote
Host</th>';
foreach ($log as $logline) { echo '<tr>';
echo '<td>' . $logline['0'] . '</td>'; echo
'<td>' . urldecode($logline['1']) . '</td>'; echo
'<td>' . date('d/m/Y', $logline['2']) . '</td>';
echo '<td>' . $logline['3'] . '</td>'; echo
'<td>' . $logline['4'] . '</td>';
echo '</tr>';
}
echo '</table>';
You can also use custom functions to filter out search engines
and crawlers. Or create graphs using PHP/SWF Charts
(http://www.maani.us/charts/index.php). The possibilities are
endless, and you can do all kinds of things!
In Conclusion... In this article I have shown
you have to create a logging module for your own PHP website,
using nothing more than PHP and its built-in functions. To view
the log file you need to parse it using PHP, and then display it
in whatever way you like. It is up to you to create a kick-ass
traffic analyzer.
If you still prefer to use a pre-built traffic analyzer, have a
look at http://www.hotscripts.com.
About the author:
Dennis Pallett is a young tech writer, with much experience in
ASP, PHP and other web technologies. He enjoys writing, and has
written several articles and tutorials. To find more of his
work, look at his websites: http://www.phpit.net, http://www.aspit.net and http://www.ezfaqs.com
