1;;; find-lisp.el --- emulation of find in Emacs Lisp
2
3;; Author: Peter Breton
4;; Created: Fri Mar 26 1999
5;; Keywords: unix
6
7;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004,
8;;   2005, 2006, 2007 Free Software Foundation, Inc.
9
10;; This file is part of GNU Emacs.
11
12;; GNU Emacs is free software; you can redistribute it and/or modify
13;; it under the terms of the GNU General Public License as published by
14;; the Free Software Foundation; either version 2, or (at your option)
15;; any later version.
16
17;; GNU Emacs is distributed in the hope that it will be useful,
18;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20;; GNU General Public License for more details.
21
22;; You should have received a copy of the GNU General Public License
23;; along with GNU Emacs; see the file COPYING.  If not, write to the
24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
25;; Boston, MA 02110-1301, USA.
26
27;;; Commentary:
28;;
29;; This is a very generalized form of find; it basically implements a
30;; recursive directory descent. The conditions which bound the search
31;; are expressed as predicates, and I have not addressed the question
32;; of how to wrap up the common chores that find does in a simpler
33;; format than writing code for all the various predicates.
34;;
35;; Some random thoughts are to express simple queries directly with
36;; user-level functions, and perhaps use some kind of forms interface
37;; for medium-level queries. Really complicated queries can be
38;; expressed in Lisp.
39;;
40
41;;; Todo
42;;
43;; It would be nice if we could sort the results without running the find
44;; again. Maybe that could work by storing the original file attributes?
45
46;;; Code:
47
48(require 'dired)
49
50(defvar dired-buffers)
51(defvar dired-subdir-alist)
52
53;; Internal variables
54
55(defvar find-lisp-regexp nil
56  "Internal variable.")
57
58(defconst find-lisp-line-indent "  "
59  "Indentation for dired file lines.")
60
61(defvar find-lisp-file-predicate nil
62  "Predicate for choosing to include files.")
63
64(defvar find-lisp-directory-predicate nil
65  "Predicate for choosing to descend into directories.")
66
67;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
68;; Debugging Code
69;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
70
71(defvar find-lisp-debug-buffer "*Find Lisp Debug*"
72  "Buffer for debugging information.")
73
74(defvar find-lisp-debug nil
75  "Whether debugging is enabled.")
76
77(defun find-lisp-debug-message (message)
78  "Print a debug message MESSAGE in `find-lisp-debug-buffer'."
79  (set-buffer (get-buffer-create find-lisp-debug-buffer))
80  (goto-char (point-max))
81  (insert message "\n"))
82
83;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
84;; Directory and File predicates
85;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
86
87(defun find-lisp-default-directory-predicate  (dir parent)
88  "True if DIR is not a dot file, and not a symlink.
89PARENT is the parent directory of DIR."
90  (and find-lisp-debug
91       (find-lisp-debug-message
92	(format "Processing directory %s in %s" dir parent)))
93  ;; Skip current and parent directories
94  (not (or (string= dir ".")
95	   (string= dir "..")
96	   ;; Skip directories which are symlinks
97	   ;; Easy way to circumvent recursive loops
98	   (file-symlink-p (expand-file-name dir parent)))))
99
100(defun find-lisp-default-file-predicate  (file dir)
101  "True if FILE matches `find-lisp-regexp'.
102DIR is the directory containing FILE."
103  (and find-lisp-debug
104       (find-lisp-debug-message
105	(format "Processing file %s in %s" file dir)))
106  (and (not (file-directory-p (expand-file-name file dir)))
107       (string-match find-lisp-regexp file)))
108
109(defun find-lisp-file-predicate-is-directory  (file dir)
110  "True if FILE is a directory.
111Argument DIR is the directory containing FILE."
112  (and find-lisp-debug
113       (find-lisp-debug-message
114	(format "Processing file %s in %s" file dir)))
115  (and (file-directory-p (expand-file-name file dir))
116       (not (or (string= file ".")
117		(string= file "..")))))
118
119;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
120;; Find functions
121;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
122
123(defun find-lisp-find-files (directory regexp)
124  "Find files in DIRECTORY which match REGEXP."
125  (let ((file-predicate      'find-lisp-default-file-predicate)
126	(directory-predicate 'find-lisp-default-directory-predicate)
127	(find-lisp-regexp regexp))
128    (find-lisp-find-files-internal
129     directory
130     file-predicate
131     directory-predicate)))
132
133;; Workhorse function
134(defun find-lisp-find-files-internal (directory file-predicate
135						directory-predicate)
136  "Find files under DIRECTORY which satisfy FILE-PREDICATE.
137FILE-PREDICATE is a function which takes two arguments: the file and its
138directory.
139
140DIRECTORY-PREDICATE is used to decide whether to descend into directories.
141It is a function which takes two arguments, the directory and its parent."
142  (setq directory (file-name-as-directory directory))
143  (let (results sub-results)
144    (dolist (file (directory-files directory nil nil t))
145      (let ((fullname (expand-file-name file directory)))
146	(when (file-readable-p (expand-file-name file directory))
147	  ;; If a directory, check it we should descend into it
148	  (and (file-directory-p fullname)
149	       (funcall directory-predicate file directory)
150	       (progn
151		 (setq sub-results
152		       (find-lisp-find-files-internal
153			fullname
154			file-predicate
155			directory-predicate))
156		 (if results
157		     (nconc results sub-results)
158		   (setq results sub-results))))
159	  ;; For all files and directories, call the file predicate
160	  (and (funcall file-predicate file directory)
161	       (if results
162		   (nconc results (list fullname))
163		 (setq results (list fullname)))))))
164    results))
165
166;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
167;; Find-dired all in Lisp
168;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
169
170;;;###autoload
171(defun find-lisp-find-dired (dir regexp)
172  "Find files in DIR, matching REGEXP."
173  (interactive "DFind files in directory: \nsMatching regexp: ")
174  (let ((find-lisp-regexp regexp))
175    (find-lisp-find-dired-internal
176     dir
177     'find-lisp-default-file-predicate
178     'find-lisp-default-directory-predicate
179     "*Find Lisp Dired*")))
180
181;; Just the subdirectories
182;;;###autoload
183(defun find-lisp-find-dired-subdirectories (dir)
184  "Find all subdirectories of DIR."
185  (interactive "DFind subdirectories of directory: ")
186  (find-lisp-find-dired-internal
187   dir
188   'find-lisp-file-predicate-is-directory
189   'find-lisp-default-directory-predicate
190   "*Find Lisp Dired Subdirectories*"))
191
192;; Most of this is lifted from find-dired.el
193;;
194(defun find-lisp-find-dired-internal (dir file-predicate
195					  directory-predicate buffer-name)
196  "Run find (Lisp version) and go into Dired mode on a buffer of the output."
197  (let ((dired-buffers dired-buffers)
198	buf
199	(regexp find-lisp-regexp))
200    ;; Expand DIR ("" means default-directory), and make sure it has a
201    ;; trailing slash.
202    (setq dir (file-name-as-directory (expand-file-name dir)))
203    ;; Check that it's really a directory.
204    (or (file-directory-p dir)
205	(error "find-dired needs a directory: %s" dir))
206    (or
207     (and (buffer-name)
208	  (string= buffer-name (buffer-name)))
209	(switch-to-buffer (setq buf (get-buffer-create buffer-name))))
210    (widen)
211    (kill-all-local-variables)
212    (setq buffer-read-only nil)
213    (erase-buffer)
214    (setq default-directory dir)
215    (dired-mode dir)
216
217    (use-local-map (append (make-sparse-keymap) (current-local-map)))
218
219    (make-local-variable 'find-lisp-file-predicate)
220    (setq find-lisp-file-predicate file-predicate)
221    (make-local-variable 'find-lisp-directory-predicate)
222    (setq find-lisp-directory-predicate directory-predicate)
223    (make-local-variable 'find-lisp-regexp)
224    (setq find-lisp-regexp regexp)
225
226    (make-local-variable 'revert-buffer-function)
227    (setq revert-buffer-function
228	  (function
229	   (lambda(ignore1 ignore2)
230	     (find-lisp-insert-directory
231	      default-directory
232	      find-lisp-file-predicate
233	      find-lisp-directory-predicate
234	      'ignore)
235	     )
236	   ))
237
238    ;; Set subdir-alist so that Tree Dired will work:
239    (if (fboundp 'dired-simple-subdir-alist)
240	;; will work even with nested dired format (dired-nstd.el,v 1.15
241	;; and later)
242	(dired-simple-subdir-alist)
243      ;; else we have an ancient tree dired (or classic dired, where
244      ;; this does no harm)
245      (set (make-local-variable 'dired-subdir-alist)
246	   (list (cons default-directory (point-min-marker)))))
247    (find-lisp-insert-directory
248     dir file-predicate directory-predicate 'ignore)
249    (goto-char (point-min))
250    (dired-goto-next-file)))
251
252(defun find-lisp-insert-directory  (dir
253				    file-predicate
254				    directory-predicate
255				    sort-function)
256  "Insert the results of `find-lisp-find-files' in the current buffer."
257  (let ((buffer-read-only nil)
258	(files (find-lisp-find-files-internal
259		dir
260		file-predicate
261		directory-predicate))
262	(len (length dir)))
263    (erase-buffer)
264    ;; Subdir headlerline must come first because the first marker in
265    ;; subdir-alist points there.
266    (insert find-lisp-line-indent dir ":\n")
267    ;; Make second line a ``find'' line in analogy to the ``total'' or
268    ;; ``wildcard'' line.
269    ;;
270    ;; No analog for find-lisp?
271    (insert find-lisp-line-indent "\n")
272    ;; Run the find function
273    (mapcar
274     (function
275      (lambda(file)
276	(find-lisp-find-dired-insert-file
277	 (substring file len)
278	 (current-buffer))))
279     (sort files 'string-lessp))
280    ;; FIXME: Sort function is ignored for now
281    ;; (funcall sort-function files))
282    (goto-char (point-min))
283    (dired-goto-next-file)))
284
285;;;###autoload
286(defun find-lisp-find-dired-filter (regexp)
287  "Change the filter on a find-lisp-find-dired buffer to REGEXP."
288  (interactive "sSet filter to regexp: ")
289  (setq find-lisp-regexp regexp)
290  (revert-buffer))
291
292(defun find-lisp-find-dired-insert-file (file buffer)
293  (set-buffer buffer)
294  (insert find-lisp-line-indent
295	  (find-lisp-format file (file-attributes file 'string) (list "")
296			  (current-time))))
297
298;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
299;; Lifted from ls-lisp. We don't want to require it, because that
300;; would alter the insert-directory function.
301;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
302
303(defun find-lisp-format (file-name file-attr switches now)
304  (let ((file-type (nth 0 file-attr)))
305    (concat (if (memq ?i switches)	; inode number
306		(format "%6d " (nth 10 file-attr)))
307	    ;; nil is treated like "" in concat
308	    (if (memq ?s switches)	; size in K
309		(format "%4d " (1+ (/ (nth 7 file-attr) 1024))))
310	    (nth 8 file-attr)		; permission bits
311	    (format " %3d %-8s %-8s %8d "
312		    (nth 1 file-attr)	; no. of links
313		    (if (numberp (nth 2 file-attr))
314			(int-to-string (nth 2 file-attr))
315		      (nth 2 file-attr)) ; uid
316		    (if (eq system-type 'ms-dos)
317			"root"		; everything is root on MSDOS.
318		      (if (numberp (nth 3 file-attr))
319			  (int-to-string (nth 3 file-attr))
320			(nth 3 file-attr))) ; gid
321		    (nth 7 file-attr)	; size in bytes
322		    )
323	    (find-lisp-format-time file-attr switches now)
324	    " "
325	    file-name
326	    (if (stringp file-type)	; is a symbolic link
327		(concat " -> " file-type)
328	      "")
329	    "\n")))
330
331(defun find-lisp-time-index (switches)
332  ;; Return index into file-attributes according to ls SWITCHES.
333  (cond
334   ((memq ?c switches) 6)		; last mode change
335   ((memq ?u switches) 4)		; last access
336   ;; default is last modtime
337   (t 5)))
338
339(defun find-lisp-format-time (file-attr switches now)
340  ;; Format time string for file with attributes FILE-ATTR according
341  ;; to SWITCHES (a list of ls option letters of which c and u are recognized).
342  ;; Use the same method as `ls' to decide whether to show time-of-day or year,
343  ;; depending on distance between file date and NOW.
344  (let* ((time (nth (find-lisp-time-index switches) file-attr))
345	 (diff16 (- (car time) (car now)))
346	 (diff (+ (ash diff16 16) (- (car (cdr time)) (car (cdr now)))))
347	 (past-cutoff (- (* 6 30 24 60 60)))	; 6 30-day months
348	 (future-cutoff (* 60 60)))		; 1 hour
349    (format-time-string
350     (if (and
351	  (<= past-cutoff diff) (<= diff future-cutoff)
352	  ;; Sanity check in case `diff' computation overflowed.
353	  (<= (1- (ash past-cutoff -16)) diff16)
354	  (<= diff16 (1+ (ash future-cutoff -16))))
355	 "%b %e %H:%M"
356       "%b %e  %Y")
357     time)))
358
359(provide 'find-lisp)
360
361;;; arch-tag: a711374c-f12a-46f6-aa18-ba7d77b9602a
362;;; find-lisp.el ends here
363