The php script to zip and download the folder does not work but the path is valid

The problem is that the script below is downloading a 0 bytes zip file when the folder has lots of files.

I have also tested this with if (file_exists="/folder/path/file.txt) clause and the script seems to be ok with finding the file. What am I doing wrong?

<?php
// Define the folder to be zipped
$folder_path = '/CA11.2.4/logs/';




// Define the name of the zipped file with a timestamp
$zip_file_name = 'logs_' . date('Ymd_His') . '.zip';

// Create a new ZipArchive instance
$zip = new ZipArchive();

// Open the zip file for writing
if ($zip->open($zip_file_name, ZipArchive::CREATE) !== TRUE) {
    die ('Could not create zip archive');
}

// Add the files from the folder to the zip file
$dir = opendir($folder_path);
while ($file = readdir($dir)) {
    if (is_file($folder_path . $file)) {
        $zip->addFile($folder_path . $file, $file);
    }
}

// Close the directory handle
closedir($dir);

// Close the zip file
$zip->close();

// Set headers to force download the zip file
header('Content-Type: application/zip');
header('Content-Disposition: attachment; filename="' . $zip_file_name . '"');
header('Content-Length: ' . filesize($zip_file_name));

// Send the zip file to the client for download
readfile($zip_file_name);

// Delete the zip file from the server
//unlink($zip_file_name);

// Redirect back to the referring page
//header('Location: ' . $_SERVER['HTTP_REFERER']); 
?>

I had initially suspected maybe its not detecting the path so I added this snippet and commented out other code to verify and it worked. The path was found.

<?php
$path = '/path/to/folder/file.txt';

if (file_exists($path)) {
    echo 'Path exists on server';
} else {
    echo 'Path does not exist on server';
}

It seems to me, that the problem is most likely a path problem, not Zip problem. in PHP, in my experience, it's always better to use absolute paths and not assume that 2 separate files will know/understand where they are located related to X.

// Define the name of the zipped file with a timestamp
$zip_file_name = 'logs_' . date('Ymd_His') . '.zip';
$zip_location = '/tmp/' . $zip_file_name;

// Open the zip file for writing
if ($zip->open($zip_location, ZipArchive::CREATE) !== TRUE) {
    die ('Could not create zip archive');
}

and then download it:

<?php
$path = '/tmp/file_name_where_previous_script_created_it.zip';

if (file_exists($path)) {
    echo 'Path exists on server';
} else {
    echo 'Path does not exist on server';
}