wavelog/install/includes/install_config/install_lib.php

<?php

// Function to check if a PHP extension is installed
function isExtensionInstalled($extensionName) {
	return in_array($extensionName, get_loaded_extensions());
}

// function to switch the language based on the user selection
function switch_lang($new_language) {
	global $gt_conf;
	setcookie($gt_conf['lang_cookie'], $new_language);
}

// check if page is called with https or not
function is_https() {
	if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on') {
		return true;
	}
	if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
		return true;
	}
	if (!empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] === 'on') {
		return true;
	}
	return false;
}

// Folder permission checks
function is_really_writable($path) {

	// Check if the folder exists
	if (!file_exists($path)) {
		log_message('error', 'is_really_writable(): File "'.$path.'" does not exist.');
		return false;
	}

	// Check if the folder is writable
	try {
		if (is_writable($path)) {
			// Check if the subdirectories are writable (recursive check)
			$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));
			foreach ($iterator as $item) {
				if ($item->isDir() && basename($item->getPathName()) != '..') {
					if (!is_writable($item->getRealPath())) {
						return false;
					}
				}
			}

			return true;
		}
	} catch (Exception $e) {
		log_message('error', 'is_really_writable(): Something went wrong while testing write permissions.');
		return false;
	}

	return false;
}

function verify_log() {
    global $logfile;

    if (!file_exists($logfile)) {
        if (touch($logfile)) {
            if(is_writable($logfile)) {
				$log_header = "Wavelog Installer Debug Log\n-------\nLog Location: $logfile\n\n";
				file_put_contents($logfile, $log_header, FILE_APPEND);
				return true;
			} else {
				return false;
			}
        } else {
            return false;
        }
    } else {
        return is_writable($logfile);
    }
}

function country2flag($code) {
	$code = strtoupper($code);

	$offset = 0x1F1E6;
	$code_p1 = $offset + ord($code[0]) - ord('A');
	$code_p2 = $offset + ord($code[1]) - ord('A');

	$flag = mb_chr($code_p1, 'UTF-8') . mb_chr($code_p2, 'UTF-8');
	return $flag;
}

// Function to read the debug logfile
function read_logfile() {
	if (verify_log()) {
		global $logfile;
		$file_content = file_get_contents($logfile);
		echo $file_content;
	} else {
        echo "Log file is not available.";
    }
}

// Function to log messages in the installer logfile
function log_message($level, $message) {
	if (verify_log()) {
		global $logfile;
		$level = strtoupper($level);
		$timestamp = date("Y-m-d H:i:s");
		$logMessage = $level . " - " . $timestamp . " --> " . $message . PHP_EOL;
		file_put_contents($logfile, $logMessage, FILE_APPEND);
	} else {
        echo "Log file is not available or not writable.";
    }
}

// Custom error handler
function customError($errno, $errstr, $errfile, $errline) {
    $message = "[$errno] $errstr in $errfile on line $errline";
    log_message('error', $message);
}

// Detect webserver and version
function detect_webserver() {
   return $_SERVER['SERVER_SOFTWARE'] ?? __("not detected");
}

// Detect nginx setting for PHP file processing
function detect_nginx_php_setting($http_scheme) {
   $ch = curl_init($http_scheme.'://'.$_SERVER['HTTP_HOST'].'/install/nginx.php/test');
   curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
   curl_setopt($ch, CURLOPT_HEADER, 0);
   $data = curl_exec($ch);
   $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
   return $code;
}

function installer_required_modules() {
   global $installer_required_modules;
   $not_found_modules = array();
   foreach ($installer_required_modules as $module) {
      if (!extension_loaded($module)) {
         array_push($not_found_modules, 'php-'.$module);
      }
   }
   return $not_found_modules;
}