lisp/find-lisp.el

   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 3, 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.
  89 PARENT 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'.
 102 DIR 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.
 111 Argument 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.
 137 FILE-PREDICATE is a function which takes two arguments: the file and its
 138 directory.
 139
 140 DIRECTORY-PREDICATE is used to decide whether to descend into directories.
 141 It 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     (mapc
 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