detectNewLineUpdatesOnFile.php

<?php
  $fileCache = "LastLine.txt";
  $oldLastLine = getLastLine($fileCache);

  function getLastLine($cachePath)
  {
    if (file_exists($cachePath))
    return file_get_contents($cachePath);

    return 0;
  }

  function fileRead($path) {
    $fileHandle = fopen($path, 'rb');

    while (($line = fgets($fileHandle)) !== false) {
      yield rtrim($line, "\r\n");
    }

    fclose($fileHandle);
  }

  $lastLine = 0;
  $updates = "";
  foreach (fileRead(".gitignore") as $line) {
    $lastLine++;

    if ($lastLine > $oldLastLine) {
      $updates .= $line . PHP_EOL;
    }
  }

  file_put_contents($fileCache, $lastLine);

  echo $updates;