Slightly Remarkable

The script started off with some simple configuration…

1. <?php
2. $file = 'data/data_tracker.txt';
3. $maxlen = 300000; // bytes/chars before file truncation begins
4. $input = '<p style="padding:0; line-height:130%;"><strong>'
5. .'IP: '.getenv('REMOTE_ADDR'). "</strong><br />\n"
6. .' <span style="font-size:85%;">DT: '.date("M jS, Y - g:i a"). "<br />\n"
7. .' PG: '.getenv('REQUEST_URI'). "<br /></span></p>\n\n";
8. ?>
9. Download this code: tracker_1.txt

The settings are pretty clear: $file is the location of the tracking file to be written to, $maxlen is the maximum filesize (in bytes) that $file can reach, and $input is what will be prepended to the file. Let’s move on.

1. <?php
2.  
3. if(@$handle = fopen($file, 'r')){
4. $data = @fread($handle, filesize($file));
5. fclose($handle);
6. }
7.  
8. while(strlen($data) > $maxlen){
9. $temp = explode("\n\n", $data);
10. unset($temp[count($temp)-1]);
11. $data = implode("\n\n", $temp);
12. }
13.  
14. if(@$handle = fopen($file, 'w')){
15. fwrite($handle, $input.$data);
16. fclose($handle);
17. unset($file, $maxlen, $input, $data, $temp, $handle);
18. }
19.  
20. ?>
21. Download this code: tracker_2.txt

The first thing we do is open and read the file. The contents of $file are loaded into the $data variable.

Next is the best part of the script. We run a while loop, checking the strlen() of the $data variable, and making sure that it is greater than the $maxlen. As long as it is, we can delete chunks of data at a time. We don’t want to remove each letter until it is at exactly $maxlen in bytes, but we want to remove the oldest chunks of data until the amount of bytes is less than or equal to $maxlen. Generally, the file size will be kept less than $maxlen, depending on the size of each chunk.

The last part just writes the new data, following truncation (if necessary), and prepends $input.

Anyway, I found this routine helpful and figured I’d share it with anyone who may be interested in accomplishing something similar. Download the entire code: tracker_3.txt.