+ /**
+ * @var string File containing the current version
+ */
+ public static $VERSION_FILE = 'shaarli_version.php';
+
+ private static $GIT_URL = 'https://raw.githubusercontent.com/shaarli/Shaarli';
+ private static $GIT_BRANCHES = array('latest', 'stable');
+ private static $VERSION_START_TAG = '<?php /* ';
+ private static $VERSION_END_TAG = ' */ ?>';
+
+ /**
+ * Gets the latest version code from the Git repository
+ *
+ * The code is read from the raw content of the version file on the Git server.
+ *
+ * @param string $url URL to reach to get the latest version.
+ * @param int $timeout Timeout to check the URL (in seconds).
+ *
+ * @return mixed the version code from the repository if available, else 'false'
+ */
+ public static function getLatestGitVersionCode($url, $timeout=2)
+ {
+ list($headers, $data) = get_http_response($url, $timeout);
+
+ if (strpos($headers[0], '200 OK') === false) {
+ error_log('Failed to retrieve ' . $url);
+ return false;
+ }
+
+ return $data;
+ }
+
+ /**
+ * Retrieve the version from a remote URL or a file.
+ *
+ * @param string $remote URL or file to fetch.
+ * @param int $timeout For URLs fetching.
+ *
+ * @return bool|string The version or false if it couldn't be retrieved.
+ */
+ public static function getVersion($remote, $timeout = 2)
+ {
+ if (startsWith($remote, 'http')) {
+ if (($data = static::getLatestGitVersionCode($remote, $timeout)) === false) {
+ return false;
+ }
+ } else {
+ if (! is_file($remote)) {
+ return false;
+ }
+ $data = file_get_contents($remote);
+ }
+
+ return str_replace(
+ array(self::$VERSION_START_TAG, self::$VERSION_END_TAG, PHP_EOL),
+ array('', '', ''),
+ $data
+ );
+ }
+
+ /**
+ * Checks if a new Shaarli version has been published on the Git repository
+ *
+ * Updates checks are run periodically, according to the following criteria:
+ * - the update checks are enabled (install, global config);
+ * - the user is logged in (or this is an open instance);
+ * - the last check is older than a given interval;
+ * - the check is non-blocking if the HTTPS connection to Git fails;
+ * - in case of failure, the update file's modification date is updated,
+ * to avoid intempestive connection attempts.
+ *
+ * @param string $currentVersion the current version code
+ * @param string $updateFile the file where to store the latest version code
+ * @param int $checkInterval the minimum interval between update checks (in seconds
+ * @param bool $enableCheck whether to check for new versions
+ * @param bool $isLoggedIn whether the user is logged in
+ * @param string $branch check update for the given branch
+ *
+ * @throws Exception an invalid branch has been set for update checks
+ *
+ * @return mixed the new version code if available and greater, else 'false'
+ */
+ public static function checkUpdate($currentVersion,
+ $updateFile,
+ $checkInterval,
+ $enableCheck,
+ $isLoggedIn,
+ $branch='stable')
+ {
+ // Do not check versions for visitors
+ // Do not check if the user doesn't want to
+ // Do not check with dev version
+ if (! $isLoggedIn || empty($enableCheck) || $currentVersion === 'dev') {
+ return false;
+ }
+
+ if (is_file($updateFile) && (filemtime($updateFile) > time() - $checkInterval)) {
+ // Shaarli has checked for updates recently - skip HTTP query
+ $latestKnownVersion = file_get_contents($updateFile);
+
+ if (version_compare($latestKnownVersion, $currentVersion) == 1) {
+ return $latestKnownVersion;
+ }
+ return false;
+ }
+
+ if (! in_array($branch, self::$GIT_BRANCHES)) {
+ throw new Exception(
+ 'Invalid branch selected for updates: "' . $branch . '"'
+ );
+ }
+
+ // Late Static Binding allows overriding within tests
+ // See http://php.net/manual/en/language.oop5.late-static-bindings.php
+ $latestVersion = static::getVersion(
+ self::$GIT_URL . '/' . $branch . '/' . self::$VERSION_FILE
+ );
+
+ if (! $latestVersion) {
+ // Only update the file's modification date
+ file_put_contents($updateFile, $currentVersion);
+ return false;
+ }
+
+ // Update the file's content and modification date
+ file_put_contents($updateFile, $latestVersion);
+
+ if (version_compare($latestVersion, $currentVersion) == 1) {
+ return $latestVersion;
+ }
+
+ return false;
+ }
+
+ /**
+ * Checks the PHP version to ensure Shaarli can run
+ *
+ * @param string $minVersion minimum PHP required version
+ * @param string $curVersion current PHP version (use PHP_VERSION)
+ *
+ * @throws Exception the PHP version is not supported
+ */
+ public static function checkPHPVersion($minVersion, $curVersion)
+ {
+ if (version_compare($curVersion, $minVersion) < 0) {
+ $msg = t(
+ 'Your PHP version is obsolete!'
+ . ' Shaarli requires at least PHP %s, and thus cannot run.'
+ . ' Your PHP version has known security vulnerabilities and should be'
+ . ' updated as soon as possible.'
+ );
+ throw new Exception(sprintf($msg, $minVersion));
+ }
+ }