Create service/utils/file.js

Add a new utility module for file/directory tools. Currently it
contains only the filesystem-name sanitization code that used to
live in service/plugins/sftp.js (used when creating filesystem
objects with names based on device names).

Author: ferdnyc

src/service/utils/file.js

@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: GSConnect Developers https://github.com/GSConnect
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+
+/**
+ * Sanitize a name when creating as a directory (or symlink, etc.)
+ *
+ * Note: %name CANNOT be a full path, as all of its path separators
+ *       will be replaced as part of sanitization.
+ *
+ * @param {string} name - The name to sanitize
+ * @returns {string} The sanitized name
+ */
+export function safe_dirname(name) {
+    let safe_name = name.replace('/', '∕');
+    if (safe_name === '.')
+        safe_name = '·';
+    else if (safe_name === '..')
+        safe_name = '··';
+    return safe_name;
+}