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 ;; Time-stamp: <2001-07-16 12:42:35 pavel>
   7
   8 ;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
   9 ;;   2005 Free Software Foundation, Inc.
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software; you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation; either version 2, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29 ;;
  30 ;; This is a very generalized form of find; it basically implements a
  31 ;; recursive directory descent. The conditions which bound the search
  32 ;; are expressed as predicates, and I have not addressed the question
  33 ;; of how to wrap up the common chores that find does in a simpler
  34 ;; format than writing code for all the various predicates.
  35 ;;
  36 ;; Some random thoughts are to express simple queries directly with
  37 ;; user-level functions, and perhaps use some kind of forms interface
  38 ;; for medium-level queries. Really complicated queries can be
  39 ;; expressed in Lisp.
  40 ;;
  41
  42 ;;; Todo
  43 ;;
  44 ;; It would be nice if we could sort the results without running the find
  45 ;; again. Maybe that could work by storing the original file attributes?
  46
  47 ;;; Code:
  48
  49 ;; Internal variables
  50
  51 (defvar find-lisp-regexp nil
  52   "Internal variable.")
  53
  54 (defconst find-lisp-line-indent "  "
  55   "Indentation for dired file lines.")
  56
  57 (defvar find-lisp-file-predicate nil
  58   "Predicate for choosing to include files.")
  59
  60 (defvar find-lisp-directory-predicate nil
  61   "Predicate for choosing to descend into directories.")
  62
  63 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  64 ;; Debugging Code
  65 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  66
  67 (defvar find-lisp-debug-buffer "*Find Lisp Debug*"
  68   "Buffer for debugging information.")
  69
  70 (defvar find-lisp-debug nil
  71   "Whether debugging is enabled.")
  72
  73 (defun find-lisp-debug-message (message)
  74   "Print a debug message MESSAGE in `find-lisp-debug-buffer'."
  75   (set-buffer (get-buffer-create find-lisp-debug-buffer))
  76   (goto-char (point-max))
  77   (insert message "\n"))
  78
  79 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  80 ;; Directory and File predicates
  81 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  82
  83 (defun find-lisp-default-directory-predicate  (dir parent)
  84   "True if DIR is not a dot file, and not a symlink.
  85 PARENT is the parent directory of DIR."
  86   (and find-lisp-debug
  87        (find-lisp-debug-message
  88         (format "Processing directory %s in %s" dir parent)))
  89   ;; Skip current and parent directories
  90   (not (or (string= dir ".")
  91            (string= dir "..")
  92            ;; Skip directories which are symlinks
  93            ;; Easy way to circumvent recursive loops
  94            (file-symlink-p dir))))
  95
  96 (defun find-lisp-default-file-predicate  (file dir)
  97   "True if FILE matches `find-lisp-regexp'.
  98 DIR is the directory containing FILE."
  99   (and find-lisp-debug
 100        (find-lisp-debug-message
 101         (format "Processing file %s in %s" file dir)))
 102   (and (not (file-directory-p (expand-file-name file dir)))
 103        (string-match find-lisp-regexp file)))
 104
 105 (defun find-lisp-file-predicate-is-directory  (file dir)
 106   "True if FILE is a directory.
 107 Argument DIR is the directory containing FILE."
 108   (and find-lisp-debug
 109        (find-lisp-debug-message
 110         (format "Processing file %s in %s" file dir)))
 111   (and (file-directory-p (expand-file-name file dir))
 112        (not (or (string= file ".")
 113                 (string= file "..")))))
 114
 115 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 116 ;; Find functions
 117 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 118
 119 (defun find-lisp-find-files (directory regexp)
 120   "Find files in DIRECTORY which match REGEXP."
 121   (let ((file-predicate      'find-lisp-default-file-predicate)
 122         (directory-predicate 'find-lisp-default-directory-predicate)
 123         (find-lisp-regexp regexp))
 124     (find-lisp-find-files-internal
 125      directory
 126      file-predicate
 127      directory-predicate)))
 128
 129 ;; Workhorse function
 130 (defun find-lisp-find-files-internal (directory file-predicate
 131                                                 directory-predicate)
 132   "Find files under DIRECTORY which satisfy FILE-PREDICATE.
 133 FILE-PREDICATE is a function which takes two arguments: the file and its
 134 directory.
 135
 136 DIRECTORY-PREDICATE is used to decide whether to descend into directories.
 137 It is a function which takes two arguments, the directory and its parent."
 138   (setq directory (file-name-as-directory directory))
 139   (let (results sub-results)
 140     (dolist (file (directory-files directory nil nil t))
 141       (let ((fullname (expand-file-name file directory)))
 142         (when (file-readable-p (expand-file-name file directory))
 143           ;; If a directory, check it we should descend into it
 144           (and (file-directory-p fullname)
 145                (funcall directory-predicate file directory)
 146                (progn
 147                  (setq sub-results
 148                        (find-lisp-find-files-internal
 149                         fullname
 150                         file-predicate
 151                         directory-predicate))
 152                  (if results
 153                      (nconc results sub-results)
 154                    (setq results sub-results))))
 155           ;; For all files and directories, call the file predicate
 156           (and (funcall file-predicate file directory)
 157                (if results
 158                    (nconc results (list fullname))
 159                  (setq results (list fullname)))))))
 160     results))
 161
 162 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 163 ;; Find-dired all in Lisp
 164 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 165
 166 ;;;###autoload
 167 (defun find-lisp-find-dired (dir regexp)
 168   "Find files in DIR, matching REGEXP."
 169   (interactive "DFind files in directory: \nsMatching regexp: ")
 170   (let ((find-lisp-regexp regexp))
 171     (find-lisp-find-dired-internal
 172      dir
 173      'find-lisp-default-file-predicate
 174      'find-lisp-default-directory-predicate
 175      "*Find Lisp Dired*")))
 176
 177 ;; Just the subdirectories
 178 ;;;###autoload
 179 (defun find-lisp-find-dired-subdirectories (dir)
 180   "Find all subdirectories of DIR."
 181   (interactive "DFind subdirectories of directory: ")
 182   (find-lisp-find-dired-internal
 183    dir
 184    'find-lisp-file-predicate-is-directory
 185    'find-lisp-default-directory-predicate
 186    "*Find Lisp Dired Subdirectories*"))
 187
 188 ;; Most of this is lifted from find-dired.el
 189 ;;
 190 (defun find-lisp-find-dired-internal (dir file-predicate
 191                                           directory-predicate buffer-name)
 192   "Run find (Lisp version) and go into Dired mode on a buffer of the output."
 193   (let ((dired-buffers dired-buffers)
 194         buf
 195         (regexp find-lisp-regexp))
 196     ;; Expand DIR ("" means default-directory), and make sure it has a
 197     ;; trailing slash.
 198     (setq dir (abbreviate-file-name
 199                (file-name-as-directory (expand-file-name dir))))
 200     ;; Check that it's really a directory.
 201     (or (file-directory-p dir)
 202         (error "find-dired needs a directory: %s" dir))
 203     (or
 204      (and (buffer-name)
 205           (string= buffer-name (buffer-name)))
 206         (switch-to-buffer (setq buf (get-buffer-create buffer-name))))
 207     (widen)
 208     (kill-all-local-variables)
 209     (setq buffer-read-only nil)
 210     (erase-buffer)
 211     (setq default-directory dir)
 212     (dired-mode dir)
 213
 214     (use-local-map (append (make-sparse-keymap) (current-local-map)))
 215
 216     (make-local-variable 'find-lisp-file-predicate)
 217     (setq find-lisp-file-predicate file-predicate)
 218     (make-local-variable 'find-lisp-directory-predicate)
 219     (setq find-lisp-directory-predicate directory-predicate)
 220     (make-local-variable 'find-lisp-regexp)
 221     (setq find-lisp-regexp regexp)
 222
 223     (make-local-variable 'revert-buffer-function)
 224     (setq revert-buffer-function
 225           (function
 226            (lambda(ignore1 ignore2)
 227              (find-lisp-insert-directory
 228               default-directory
 229               find-lisp-file-predicate
 230               find-lisp-directory-predicate
 231               'ignore)
 232              )
 233            ))
 234
 235     ;; Set subdir-alist so that Tree Dired will work:
 236     (if (fboundp 'dired-simple-subdir-alist)
 237         ;; will work even with nested dired format (dired-nstd.el,v 1.15
 238         ;; and later)
 239         (dired-simple-subdir-alist)
 240       ;; else we have an ancient tree dired (or classic dired, where
 241       ;; this does no harm)
 242       (set (make-local-variable 'dired-subdir-alist)
 243            (list (cons default-directory (point-min-marker)))))
 244     (find-lisp-insert-directory
 245      dir file-predicate directory-predicate 'ignore)
 246     (goto-char (point-min))
 247     (dired-goto-next-file)))
 248
 249 (defun find-lisp-insert-directory  (dir
 250                                     file-predicate
 251                                     directory-predicate
 252                                     sort-function)
 253   "Insert the results of `find-lisp-find-files' in the current buffer."
 254   (let ((buffer-read-only nil)
 255         (files (find-lisp-find-files-internal
 256                 dir
 257                 file-predicate
 258                 directory-predicate))
 259         (len (length dir)))
 260     (erase-buffer)
 261     ;; Subdir headlerline must come first because the first marker in
 262     ;; subdir-alist points there.
 263     (insert find-lisp-line-indent dir ":\n")
 264     ;; Make second line a ``find'' line in analogy to the ``total'' or
 265     ;; ``wildcard'' line.
 266     ;;
 267     ;; No analog for find-lisp?
 268     (insert find-lisp-line-indent "\n")
 269     ;; Run the find function
 270     (mapcar
 271      (function
 272       (lambda(file)
 273         (find-lisp-find-dired-insert-file
 274          (substring file len)
 275          (current-buffer))))
 276      (sort files 'string-lessp))
 277     ;; FIXME: Sort function is ignored for now
 278     ;; (funcall sort-function files))
 279     (goto-char (point-min))
 280     (dired-goto-next-file)))
 281
 282 ;;;###autoload
 283 (defun find-lisp-find-dired-filter (regexp)
 284   "Change the filter on a find-lisp-find-dired buffer to REGEXP."
 285   (interactive "sSet filter to regexp: ")
 286   (setq find-lisp-regexp regexp)
 287   (revert-buffer))
 288
 289 (defun find-lisp-find-dired-insert-file (file buffer)
 290   (set-buffer buffer)
 291   (insert find-lisp-line-indent
 292           (find-lisp-format file (file-attributes file) (list "")
 293                           (current-time))))
 294
 295 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 296 ;; Lifted from ls-lisp. We don't want to require it, because that
 297 ;; would alter the insert-directory function.
 298 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 299
 300 (defun find-lisp-format (file-name file-attr switches now)
 301   (let ((file-type (nth 0 file-attr)))
 302     (concat (if (memq ?i switches)      ; inode number
 303                 (format "%6d " (nth 10 file-attr)))
 304             ;; nil is treated like "" in concat
 305             (if (memq ?s switches)      ; size in K
 306                 (format "%4d " (1+ (/ (nth 7 file-attr) 1024))))
 307             (nth 8 file-attr)           ; permission bits
 308             ;; numeric uid/gid are more confusing than helpful
 309             ;; Emacs should be able to make strings of them.
 310             ;; user-login-name and user-full-name could take an
 311             ;; optional arg.
 312             (format " %3d %-8s %-8s %8d "
 313                     (nth 1 file-attr)   ; no. of links
 314                     (if (= (user-uid) (nth 2 file-attr))
 315                         (user-login-name)
 316                       (int-to-string (nth 2 file-attr)))        ; uid
 317                     (if (eq system-type 'ms-dos)
 318                         "root"          ; everything is root on MSDOS.
 319                       (int-to-string (nth 3 file-attr)))        ; gid
 320                     (nth 7 file-attr)   ; size in bytes
 321                     )
 322             (find-lisp-format-time file-attr switches now)
 323             " "
 324             file-name
 325             (if (stringp file-type)     ; is a symbolic link
 326                 (concat " -> " file-type)
 327               "")
 328             "\n")))
 329
 330 (defun find-lisp-time-index (switches)
 331   ;; Return index into file-attributes according to ls SWITCHES.
 332   (cond
 333    ((memq ?c switches) 6)               ; last mode change
 334    ((memq ?u switches) 4)               ; last access
 335    ;; default is last modtime
 336    (t 5)))
 337
 338 (defun find-lisp-format-time (file-attr switches now)
 339   ;; Format time string for file with attributes FILE-ATTR according
 340   ;; to SWITCHES (a list of ls option letters of which c and u are recognized).
 341   ;; Use the same method as `ls' to decide whether to show time-of-day or year,
 342   ;; depending on distance between file date and NOW.
 343   (let* ((time (nth (find-lisp-time-index switches) file-attr))
 344          (diff16 (- (car time) (car now)))
 345          (diff (+ (ash diff16 16) (- (car (cdr time)) (car (cdr now)))))
 346          (past-cutoff (- (* 6 30 24 60 60)))    ; 6 30-day months
 347          (future-cutoff (* 60 60)))             ; 1 hour
 348     (format-time-string
 349      (if (and
 350           (<= past-cutoff diff) (<= diff future-cutoff)
 351           ;; Sanity check in case `diff' computation overflowed.
 352           (<= (1- (ash past-cutoff -16)) diff16)
 353           (<= diff16 (1+ (ash future-cutoff -16))))
 354          "%b %e %H:%M"
 355        "%b %e  %Y")
 356      time)))
 357
 358 (provide 'find-lisp)
 359
 360 ;; Local Variables:
 361 ;; autocompile: t
 362 ;; End:
 363
 364 ;;; arch-tag: a711374c-f12a-46f6-aa18-ba7d77b9602a
 365 ;;; find-lisp.el ends here