The cron is now safely detached from the browser. It will hit $target_url exactly on the minute.
"; echo "You can completely close this page/browser, and it will keep running!
"; exit; } // If we reach here, we are running in the background CLI! // Check if it's already running to prevent multiple loops if (file_exists($lock_file)) { $last_run = filemtime($lock_file); // If lock file is younger than 3 minutes, assume it's still running if (time() - $last_run < 180) { die("Cron is already running in the background. (Lock file active)\n"); } } // Update lock file to indicate it started file_put_contents($lock_file, "Running started at: " . date('Y-m-d H:i:s')); // Set this to 1, 2, or 3 if your server has a network delay. // Example: If it hits 3 seconds late, set $advance_seconds = 3; so it triggers at 57 seconds. $advance_seconds = 0; // Infinite loop to hit the URL while (true) { // Touch lock file to indicate we are still alive touch($lock_file); $current_second = (int)date('s'); // Calculate target second based on advance time $target_second = 60 - $advance_seconds; if ($target_second == 60) $target_second = 0; // Calculate how many seconds left until 2 seconds BEFORE our target // We will sleep most of the time, then use a tight loop for perfect precision $sleep_time = 60 - $current_second - $advance_seconds; if ($sleep_time < 0) { $sleep_time += 60; } // Sleep until 2 seconds before the target hit time if ($sleep_time > 2) { sleep($sleep_time - 2); } // Tight precision loop: Check time every 10 milliseconds until it exactly hits the target while (true) { $sec = (int)date('s'); if ($sec === $target_second) { break; // EXACT MATCH! Fire immediately } usleep(10000); // 10 ms delay for ultra-precision } // Now it's the exact target second! Call the URL $ch = curl_init($target_url); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_TIMEOUT, 30); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // Force IPv4 to prevent slow DNS lookups (common cause of 2-3 sec delay) curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4); // Fire the request $response = curl_exec($ch); $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE); curl_close($ch); // Log the action if ($enable_logging) { // Log the exact precise time with milliseconds list($usec, $sec) = explode(" ", microtime()); $ms = sprintf("%03d", round($usec * 1000)); $time = date('Y-m-d H:i:s', $sec) . ".$ms"; $log_msg = "[$time] Pinged $target_url | HTTP Status: $http_code\n"; file_put_contents($log_file, $log_msg, FILE_APPEND); } // Sleep for a few seconds so we don't accidentally fire twice in the same target second sleep(5); } ?>