1 files changed, 140 insertions, 0 deletions

diff --git a/application/helper/FileUtils.php b/application/helper/FileUtils.php
new file mode 100644
index 00000000..e8a2168c
--- /dev/null
+++ b/application/helper/FileUtils.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace Shaarli\Helper;
+
+use Shaarli\Exceptions\IOException;
+
+/**
+ * Class FileUtils
+ *
+ * Utility class for file manipulation.
+ */
+class FileUtils
+{
+    /**
+     * @var string
+     */
+    protected static $phpPrefix = '<?php /* ';
+
+    /**
+     * @var string
+     */
+    protected static $phpSuffix = ' */ ?>';
+
+    /**
+     * Write data into a file (Shaarli database format).
+     * The data is stored in a PHP file, as a comment, in compressed base64 format.
+     *
+     * The file will be created if it doesn't exist.
+     *
+     * @param string $file    File path.
+     * @param mixed  $content Content to write.
+     *
+     * @return int|bool Number of bytes written or false if it fails.
+     *
+     * @throws IOException The destination file can't be written.
+     */
+    public static function writeFlatDB($file, $content)
+    {
+        if (is_file($file) && !is_writeable($file)) {
+            // The datastore exists but is not writeable
+            throw new IOException($file);
+        } elseif (!is_file($file) && !is_writeable(dirname($file))) {
+            // The datastore does not exist and its parent directory is not writeable
+            throw new IOException(dirname($file));
+        }
+
+        return file_put_contents(
+            $file,
+            self::$phpPrefix . base64_encode(gzdeflate(serialize($content))) . self::$phpSuffix
+        );
+    }
+
+    /**
+     * Read data from a file containing Shaarli database format content.
+     *
+     * If the file isn't readable or doesn't exist, default data will be returned.
+     *
+     * @param string $file    File path.
+     * @param mixed  $default The default value to return if the file isn't readable.
+     *
+     * @return mixed The content unserialized, or default if the file isn't readable, or false if it fails.
+     */
+    public static function readFlatDB($file, $default = null)
+    {
+        // Note that gzinflate is faster than gzuncompress.
+        // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
+        if (!is_readable($file)) {
+            return $default;
+        }
+
+        $data = file_get_contents($file);
+        if ($data == '') {
+            return $default;
+        }
+
+        return unserialize(
+            gzinflate(
+                base64_decode(
+                    substr($data, strlen(self::$phpPrefix), -strlen(self::$phpSuffix))
+                )
+            )
+        );
+    }
+
+    /**
+     * Recursively deletes a folder content, and deletes itself optionally.
+     * If an excluded file is found, folders won't be deleted.
+     *
+     * Additional security: raise an exception if it tries to delete a folder outside of Shaarli directory.
+     *
+     * @param string $path
+     * @param bool $selfDelete Delete the provided folder if true, only its content if false.
+     * @param array $exclude
+     */
+    public static function clearFolder(string $path, bool $selfDelete, array $exclude = []): bool
+    {
+        $skipped = false;
+
+        if (!is_dir($path)) {
+            throw new IOException(t('Provided path is not a directory.'));
+        }
+
+        if (!static::isPathInShaarliFolder($path)) {
+            throw new IOException(t('Trying to delete a folder outside of Shaarli path.'));
+        }
+
+        foreach (new \DirectoryIterator($path) as $file) {
+            if ($file->isDot()) {
+                continue;
+            }
+
+            if (in_array($file->getBasename(), $exclude, true)) {
+                $skipped = true;
+                continue;
+            }
+
+            if ($file->isFile()) {
+                unlink($file->getPathname());
+            } elseif ($file->isDir()) {
+                $skipped = static::clearFolder($file->getRealPath(), true, $exclude) || $skipped;
+            }
+        }
+
+        if ($selfDelete && !$skipped) {
+            rmdir($path);
+        }
+
+        return $skipped;
+    }
+
+    /**
+     * Checks that the given path is inside Shaarli directory.
+     */
+    public static function isPathInShaarliFolder(string $path): bool
+    {
+        $rootDirectory = dirname(dirname(dirname(__FILE__)));
+
+        return strpos(realpath($path), $rootDirectory) !== false;
+    }
+}