How can PHP handle long-running processes like rsync commands without timing out or causing the page to stop loading?

When dealing with long-running processes like rsync commands in PHP, it's important to set an appropriate time limit using the `set_time_limit()` function to prevent the script from timing out. Additionally, you can use `ignore_user_abort(true)` to allow the script to continue running even if the client disconnects. Lastly, consider running the process asynchronously using functions like `exec()` or `proc_open()` to prevent the page from stopping loading.

set_time_limit(0); // Set no time limit for the script
ignore_user_abort(true); // Allow the script to continue running even if the client disconnects

// Execute rsync command asynchronously
$command = "rsync -avz /path/to/source user@host:/path/to/destination > /dev/null 2>&1 &";
exec($command);