file_line_generator.php

<?php

function gen_file_lines($filename) {
  try {
    $fp = fopen($filename, 'r');

    while (($line = fgets($fp)) !== false) {
      yield $line;
    }
  } finally {
    if ($fp) {
      fclose($fp);
    }
  }
}

////////////////////////////////////////////////////////////////////////////////

if (!isset($argv[1])) {
  die("Usage: php " . basename(__FILE__) . " filename");
}

$startMem = memory_get_usage();
$time = microtime(true);

$numLines = 0;
foreach (gen_file_lines($argv[1]) as $line) {
  $numLines++;
  $fields = preg_split("/[\s,]+/", $line);
}

$time = microtime(true) - $time;

echo "Lines: $numLines\n";
echo "Time: " . $time * 1000 . " ms\n";
echo "Memory (start): " . ($startMem / 1024) . " kb\n";
echo "Memory (peak):  " . (memory_get_peak_usage() / 1024) . " kb\n";
echo "Memory (end):   " . (memory_get_usage() / 1024) . " kb\n";