read last line(s) from very large file with php

read_last_line.php

/**
 * read last line(s) from very large file
 *
 * @param string $filename filename to open
 * @param integer $buffer Perfoorm search of last line in [buffer] bytes got from end of file
 *
 * @return string
 */
function read_last_line(string $filename, int $buffer = 1024*1024 )
{
  $fp = fopen( $filename, 'r');
  fseek($fp, -$buffer, SEEK_END);
  $lines = [];
  while (($line = fgets($fp) ) !== false)
  {
    $lines[] = rtrim($line,"\r\n");
  }
  fclose($fp);
  return end($lines);
}