<?php

// http://www.pgregg.com/projects/php/code/ftruncate.php

$chartrunclen  = 10;

$file = '/tmp/trunc-test.txt';


$fsize = filesize($file);
echo '<br>Size of ', $file, ' before: ', $fsize, ' bytes.', "\n";


$fp = fopen($file, 'ab');
if ($fp === false) exit;

ftruncate($fp, max($fsize - $chartrunclen, 0));
fclose($fp); // close the file

clearstatcache();
$fsize2 = filesize($file);
echo '<br>Size of ', $file, ' after: ', $fsize2, ' bytes.', "\n<br>";

highlight_file(__FILE__);
?>