ambrevar/shell: Add delete-empty-directory-upward.

.local/share/common-lisp/source/ambrevar/shell.lisp

@@ -83,6 +83,16 @@ Without PREDICATES, list all files."
   (let ((*finder-include-directories* nil))
     (apply #'walk root predicates)))
 
+(export-always 'delete-empty-directory-upward)
+(defun delete-empty-directory-upward (directory)
+  "Delete directory and its parents until non-empty.
+Return the first non-deleted directory."
+  (or (and (ignore-errors (uiop:delete-empty-directory directory))
+           (delete-directory-upward
+            (uiop:pathname-parent-directory-pathname
+                 (uiop:ensure-directory-pathname directory))))
+      directory))
+
 (export-always 'make-directory)
 (defun make-directory (path)
   "Including parents."