tail/tail.function.php
<?php
/**
* Tail in PHP, capable of eating big files.
*
* @author Torleif Berger
* @link http://www.geekality.net/?p=1654
* @license http://creativecommons.org/licenses/by/3.0/
*/
function tail($file, $lines = 10, $buffer = 4096)
{
if(is_resource($file) && (get_resource_type($file) == 'file' || get_resource_type($file) == 'stream'))
$f = $file;
elseif(is_string($file))
$f = fopen($file, 'rb');
else
throw new Exception('$file must be either a resource (file or stream) or a filename.');
$output = '';
$chunk = '';
fseek($f, -1, SEEK_END);
if(fread($f, 1) != "\n")
$lines -= 1;
while(ftell($f) > 0 && $lines >= 0)
{
$seek = min(ftell($f), $buffer);
fseek($f, -$seek, SEEK_CUR);
$output = ($chunk = fread($f, $seek)).$output;
fseek($f, -mb_strlen($chunk, '8bit'), SEEK_CUR);
$lines -= substr_count($chunk, "\n");
}
while($lines++ < 0)
$output = substr($output, strpos($output, "\n")+1);
fclose($f);
return $output;
}