Common Lisp 删除指定路径下的空目录

X3J13移除了一些对路径的操做函数，只保留pathname和directory相关的基本函数，cl-fad实现了路径操做的多数接口。

CL-USER> (ql:quickload "cl-fad")
To load "cl-fad":
  Load 1 ASDF system:
    cl-fad
; Loading "cl-fad"

("cl-fad")

CL-USER> (defun delete-empty-directory (filepath)
	   (cl-fad:walk-directory filepath (lambda (file) 
					     (if (and 
						  (cl-fad:directory-pathname-p file) 
						  (null (cl-fad:list-directory file))) 
						 (progn 
						   (format t "delete ~a~%~%" file)
						   (cl-fad:delete-directory-and-files file)))) 
				  :directories t))
DELETE-EMPTY-DIRECTORY
CL-USER>

在“d:/迅雷下载”目录下新建aaaa空目录，而后执行一下语句：

CL-USER> (delete-empty-directory "d:/迅雷下载")
delete d:/迅雷下载/aaaaaa/