How to read only 5 last line of the text file in PHP?

Question

I have a file named file.txt which is update by adding lines to it.

I am reading it by this code:

$fp = fopen(\"file.txt\", \"r\");
$da         


        

Answer 1

FAST

Here is FAST method for LARGE files with LOW memory cost - I develop Wallace Maxters answer (if you want to upvote - do it on his answer) by wrap his code inside handy function and add reverse feature

function readLastLines($filename, $num, $reverse = false)
{
    $file = new \SplFileObject($filename, 'r');
    $file->seek(PHP_INT_MAX);
    $last_line = $file->key();
    $lines = new \LimitIterator($file, $last_line - $num, $last_line);
    $arr = iterator_to_array($lines);
    if($reverse) $arr = array_reverse($arr);
    return implode('',$arr);
}

// use it by
$lines = readLastLines("file.txt", 5) // return string with 5 last lines