Hit counter for each page with PHP

Question

I want to integrate a counter on my webpage, as far I've done it so the counter works. But what I really want is this counter to be specific for each page to be generated per id

<?php

session_start();

$counter_name = 'counter'.$id.'.txt';
// Check if a text file exists. If not create one and initialize it to zero.
if (!file_exists($counter_name)) {
  $f = fopen($counter_name, "w");
  fwrite($f,"0");
  fclose($f);
}
// Read the current value of our counter file
$f = fopen($counter_name,"r");
$counterVal = fread($f, filesize($counter_name));
fclose($f);
// Has visitor been counted in this session?
// If not, increase counter value by one
if(!isset($_SESSION['hasVisited'])){
  $_SESSION['hasVisited']="no";
  $counterVal++;
  $f = fopen($counter_name, "w");
  fwrite($f, $counterVal);
  fclose($f); 
}
else {
    $counterVal++;
    $f = fopen($counter_name, "w");
    fwrite($f, $counterVal);
    fclose($f);
}
$counterVal = str_pad($counterVal, 5, "0", STR_PAD_LEFT);
$chars = preg_split('//', $counterVal);
$im = imagecreatefrompng("canvas.png");
$src1 = imagecreatefrompng("$chars[1].png");
$src2 = imagecreatefrompng("$chars[2].png");
$src3 = imagecreatefrompng("$chars[3].png");
$src4 = imagecreatefrompng("$chars[4].png");
$src5 = imagecreatefrompng("$chars[5].png");
imagecopymerge($im, $src1, 0, 0, 0, 0, 15, 15, 100);
imagecopymerge($im, $src2, 15, 0, 0, 0, 15, 15, 100);
imagecopymerge($im, $src3, 30, 0, 0, 0, 15, 15, 100);
imagecopymerge($im, $src4, 45, 0, 0, 0, 15, 15, 100);
imagecopymerge($im, $src5, 60, 0, 0, 0, 15, 15, 100);
// Output and free from memory
header('Content-Type: image/png');
echo imagepng($im);
imagedestroy($im);
?>

With this code I can see only the hits for the main page. It shows on each page with the same number ex.

page 1 count: 100 
page 2 count: 100

after I refresh 50x page 1

page 1 count: 150
page 2 count: 150

The file name is counter.php and implemented on the template file with the following code

 <img style="padding-left: 2px;" alt="Hit counter" src="http://www.example.com/counter/counter.php" />

I've been searching for a solution but till now haven't found any.
Thanks in Advance.

Best Regards,
BujarA.

Answer 1

For the undefined $id variable you are using, you could use for example the path info from the server:

<?php

session_start();

$id = preg_replace('[^\w-]', '', $_SERVER['PATH_INFO']);

$counter_name = 'counter' . $id . '.txt';

// etc.

Note that I have removed all special characters to avoid problems.