How to download a file from a server in PHP?

To download a file from a server using PHP, you can use the following steps:

Open a PHP script file (e.g., download.php) and start the PHP code block.
Get the file path on the server for the file you want to download. This could be from a database or specified in the script.
Set the appropriate headers to force the browser to download the file rather than display it.
Output the file contents using readfile() function.
Optionally, you can perform additional verification or security checks.

Here is an example of the PHP code:

<?php
// Get the file path
$file = '/path/to/file.pdf';

// Check if the file exists
if (file_exists($file)) {
    // Set headers to force file download
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename="' . basename($file) . '"');
    header('Expires: 0');
    header('Cache-Control: must-revalidate');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    readfile($file);
    exit;
} else {
    // File not found
    die('Error: File not found.');
}
?>

Make sure to adjust the $file variable with the actual file path on your server.