/include/sanity_check.php

<?php
	/*
	 * WARNING!
	 *
	 * If you modify this file, you are ON YOUR OWN!
	 *
	 * Believe it or not, all of the checks below are required to succeed for
	 * tt-rss to actually function properly.
	 *
	 * If you think you have a better idea about what is or isn't required, feel
	 * free to modify the file, note though that you are therefore automatically
	 * disqualified from any further support by official channels, e.g. tt-rss.org
	 * issue tracker or the forums.
	 *
	 * If you come crying when stuff inevitably breaks, you will be mocked and told
	 * to get out. */

	function make_self_url_path() {
		$url_path = ($_SERVER['HTTPS'] != "on" ? 'http://' :  'https://') . $_SERVER["HTTP_HOST"] . parse_url($_SERVER["REQUEST_URI"], PHP_URL_PATH);

		return $url_path;
	}

	function initial_sanity_check() {

		$errors = array();

		if (!file_exists("config.php")) {
			array_push($errors, "Configuration file not found. Looks like you forgot to copy config.php-dist to config.php and edit it.");
		} else {

			require_once "sanity_config.php";

			if (file_exists("install") && !file_exists("config.php")) {
				array_push($errors, "Please copy config.php-dist to config.php or run the installer in install/");
			}

			if (strpos(PLUGINS, "auth_") === FALSE) {
				array_push($errors, "Please enable at least one authentication module via PLUGINS constant in config.php");
			}

			if (function_exists('posix_getuid') && posix_getuid() == 0) {
				array_push($errors, "Please don't run this script as root.");
			}

			if (version_compare(PHP_VERSION, '5.3.0', '<')) {
				array_push($errors, "PHP version 5.3.0 or newer required.");
			}

			if (CONFIG_VERSION != EXPECTED_CONFIG_VERSION) {
				array_push($errors, "Configuration file (config.php) has incorrect version. Update it with new options from config.php-dist and set CONFIG_VERSION to the correct value.");
			}

			if (!is_writable(CACHE_DIR . "/images")) {
				array_push($errors, "Image cache is not writable (chmod -R 777 ".CACHE_DIR."/images)");
			}

			if (!is_writable(CACHE_DIR . "/upload")) {
				array_push($errors, "Upload cache is not writable (chmod -R 777 ".CACHE_DIR."/upload)");
			}

			if (!is_writable(CACHE_DIR . "/export")) {
				array_push($errors, "Data export cache is not writable (chmod -R 777 ".CACHE_DIR."/export)");
			}

			if (!is_writable(CACHE_DIR . "/js")) {
				array_push($errors, "Javascript cache is not writable (chmod -R 777 ".CACHE_DIR."/js)");
			}

			if (strlen(FEED_CRYPT_KEY) > 0 && strlen(FEED_CRYPT_KEY) != 24) {
				array_push($errors, "FEED_CRYPT_KEY should be exactly 24 characters in length.");
			}

			if (strlen(FEED_CRYPT_KEY) > 0 && !function_exists("mcrypt_decrypt")) {
				array_push($errors, "FEED_CRYPT_KEY requires mcrypt functions which are not found.");
			}

			if (GENERATED_CONFIG_CHECK != EXPECTED_CONFIG_VERSION) {
				array_push($errors,
					"Configuration option checker sanity_config.php is outdated, please recreate it using ./utils/regen_config_checks.sh");
			}

			foreach ($requred_defines as $d) {
				if (!defined($d)) {
					array_push($errors,
						"Required configuration file parameter $d is not defined in config.php. You might need to copy it from config.php-dist.");
				}
			}

			if (SINGLE_USER_MODE) {
				$result = db_query("SELECT id FROM ttrss_users WHERE id = 1");

				if (db_num_rows($result) != 1) {
					array_push($errors, "SINGLE_USER_MODE is enabled in config.php but default admin account is not found.");
				}
			}

			if (SELF_URL_PATH == "http://example.org/tt-rss/") {
				$urlpath = preg_replace("/\w+\.php$/", "", make_self_url_path());

				array_push($errors,
						"Please set SELF_URL_PATH to the correct value for your server (possible value: <b>$urlpath</b>)");
			}

			if (!is_writable(ICONS_DIR)) {
				array_push($errors, "ICONS_DIR defined in config.php is not writable (chmod -R 777 ".ICONS_DIR.").\n");
			}

			if (!is_writable(LOCK_DIRECTORY)) {
				array_push($errors, "LOCK_DIRECTORY defined in config.php is not writable (chmod -R 777 ".LOCK_DIRECTORY.").\n");
			}

			if (!function_exists("curl_init") && !ini_get("allow_url_fopen")) {
				array_push($errors, "PHP configuration option allow_url_fopen is disabled, and CURL functions are not present. Either enable allow_url_fopen or install PHP extension for CURL.");
			}

			if (!function_exists("json_encode")) {
				array_push($errors, "PHP support for JSON is required, but was not found.");
			}

			if (DB_TYPE == "mysql" && !function_exists("mysql_connect") && !function_exists("mysqli_connect")) {
				array_push($errors, "PHP support for MySQL is required for configured DB_TYPE in config.php.");
			}

			if (DB_TYPE == "pgsql" && !function_exists("pg_connect")) {
				array_push($errors, "PHP support for PostgreSQL is required for configured DB_TYPE in config.php");
			}

			if (!function_exists("mb_strlen")) {
				array_push($errors, "PHP support for mbstring functions is required but was not found.");
			}

			if (!function_exists("hash")) {
				array_push($errors, "PHP support for hash() function is required but was not found.");
			}

			if (!function_exists("ctype_lower")) {
				array_push($errors, "PHP support for ctype functions are required by HTMLPurifier.");
			}

			if (!function_exists("iconv")) {
				array_push($errors, "PHP support for iconv is required to handle multiple charsets.");
			}

			/* if (ini_get("safe_mode")) {
				array_push($errors, "PHP safe mode setting is not supported.");
			} */

			if ((PUBSUBHUBBUB_HUB || PUBSUBHUBBUB_ENABLED) && !function_exists("curl_init")) {
				array_push($errors, "PHP support for CURL is required for PubSubHubbub.");
			}

			if (SPHINX_ENABLED && class_exists("SphinxClient")) {
				array_push($errors, "Your PHP has a separate systemwide Sphinx client installed which conflicts with the client library used by tt-rss. Either remove the system library or disable Sphinx support.");

			}

			if (!class_exists("DOMDocument")) {
				array_push($errors, "PHP support for DOMDocument is required, but was not found.");
			}
		}

		if (count($errors) > 0 && $_SERVER['REQUEST_URI']) { ?>
			<html>
			<head>
			<title>Startup failed</title>
				<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				<link rel="stylesheet" type="text/css" href="css/utility.css">
			</head>
		<body>
		<div class="floatingLogo"><img src="images/logo_small.png"></div>
			<div class="content">

			<h1>Startup failed</h1>

			<p>Tiny Tiny RSS was unable to start properly. This usually means a misconfiguration or an incomplete upgrade. Please fix
			errors indicated by the following messages:</p>

			<?php foreach ($errors as $error) { echo format_error($error); } ?>

			<p>You might want to check tt-rss <a href="http://tt-rss.org/wiki">wiki</a> or the
				<a href="http://tt-rss.org/forum">forums</a> for more information. Please search the forums before creating new topic
				for your question.</p>

		</div>
		</body>
		</html>

		<?php
			die;
		} else if (count($errors) > 0) {
			echo "Tiny Tiny RSS was unable to start properly. This usually means a misconfiguration or an incomplete upgrade.\n";
			echo "Please fix errors indicated by the following messages:\n\n";

			foreach ($errors as $error) {
				echo " * $error\n";
			}

			echo "\nYou might want to check tt-rss wiki or the forums for more information.\n";
			echo "Please search the forums before creating new topic for your question.\n";

			exit(-1);
		}
	}

	initial_sanity_check();

?>