无法在本地网络中获取http标头

Question

I'm doing a pixel tracking but when I try to get the HTTP Headers using cURL, it returns this:

Output http://image.prntscr.com/image/644e0c04a08e445c82e3381eed3b42f4.jpeg

the current code:

<?php
  $img = imagecreate(1,1);
  $white = imagecolorallocate($img, 255, 255, 255);
  imagesetpixel($img,1,1,$white);
  header("content-type: image/jpg");
  imagejpeg($img);
  imagedestroy($img);
  $file = fopen("results.txt", "a");
  $ip = $_SERVER['REMOTE_ADDR'];
  $date = date("r");
  fwrite($file, "$ip from: $_SERVER['HTTP_REFERER'] at $date");
  fclose($file);
?>

Answer 1

1. First of all add line i records.txt
2. Generate Image
3. Do ob_clean(), it will remove output if warning occures
4. Give output of image
5. do not close php tag.
6. try it with browser instead of CURL because curl output should be garbase collection because output is in binary format.

PHP:

<?php

  $file = fopen("results.txt", "a");
  $ip = $_SERVER['REMOTE_ADDR'];
  $date = date("r");
  fwrite($file, "$ip from: $_SERVER['HTTP_REFERER'] at $date");
  fclose($file);
  $img = imagecreate(1,1);
  $white = imagecolorallocate($img, 255, 255, 255);
  imagesetpixel($img,1,1,$white);
  header("content-type: image/jpg");
  ob_clean();
  imagejpeg($img);
  imagedestroy($img);