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: <2006-02-06 13:40:10 ttn>
   7
   8 ;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
   9 ;;   2005, 2006 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 (require 'dired)
  50
  51 (defvar dired-buffers)
  52 (defvar dired-subdir-alist)
  53
  54 ;; Internal variables
  55
  56 (defvar find-lisp-regexp nil
  57   "Internal variable.")
  58
  59 (defconst find-lisp-line-indent "  "
  60   "Indentation for dired file lines.")
  61
  62 (defvar find-lisp-file-predicate nil
  63   "Predicate for choosing to include files.")
  64
  65 (defvar find-lisp-directory-predicate nil
  66   "Predicate for choosing to descend into directories.")
  67
  68 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  69 ;; Debugging Code
  70 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  71
  72 (defvar find-lisp-debug-buffer "*Find Lisp Debug*"
  73   "Buffer for debugging information.")
  74
  75 (defvar find-lisp-debug nil
  76   "Whether debugging is enabled.")
  77
  78 (defun find-lisp-debug-message (message)
  79   "Print a debug message MESSAGE in `find-lisp-debug-buffer'."
  80   (set-buffer (get-buffer-create find-lisp-debug-buffer))
  81   (goto-char (point-max))
  82   (insert message "\n"))
  83
  84 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  85 ;; Directory and File predicates
  86 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  87
  88 (defun find-lisp-default-directory-predicate  (dir parent)
  89   "True if DIR is not a dot file, and not a symlink.
  90 PARENT is the parent directory of DIR."
  91   (and find-lisp-debug
  92        (find-lisp-debug-message
  93         (format "Processing directory %s in %s" dir parent)))
  94   ;; Skip current and parent directories
  95   (not (or (string= dir ".")
  96            (string= dir "..")
  97            ;; Skip directories which are symlinks
  98            ;; Easy way to circumvent recursive loops
  99            (file-symlink-p dir))))
 100
 101 (defun find-lisp-default-file-predicate  (file dir)
 102   "True if FILE matches `find-lisp-regexp'.
 103 DIR is the directory containing FILE."
 104   (and find-lisp-debug
 105        (find-lisp-debug-message
 106         (format "Processing file %s in %s" file dir)))
 107   (and (not (file-directory-p (expand-file-name file dir)))
 108        (string-match find-lisp-regexp file)))
 109
 110 (defun find-lisp-file-predicate-is-directory  (file dir)
 111   "True if FILE is a directory.
 112 Argument DIR is the directory containing FILE."
 113   (and find-lisp-debug
 114        (find-lisp-debug-message
 115         (format "Processing file %s in %s" file dir)))
 116   (and (file-directory-p (expand-file-name file dir))
 117        (not (or (string= file ".")
 118                 (string= file "..")))))
 119
 120 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 121 ;; Find functions
 122 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 123
 124 (defun find-lisp-find-files (directory regexp)
 125   "Find files in DIRECTORY which match REGEXP."
 126   (let ((file-predicate      'find-lisp-default-file-predicate)
 127         (directory-predicate 'find-lisp-default-directory-predicate)
 128         (find-lisp-regexp regexp))
 129     (find-lisp-find-files-internal
 130      directory
 131      file-predicate
 132      directory-predicate)))
 133
 134 ;; Workhorse function
 135 (defun find-lisp-find-files-internal (directory file-predicate
 136                                                 directory-predicate)
 137   "Find files under DIRECTORY which satisfy FILE-PREDICATE.
 138 FILE-PREDICATE is a function which takes two arguments: the file and its
 139 directory.
 140
 141 DIRECTORY-PREDICATE is used to decide whether to descend into directories.
 142 It is a function which takes two arguments, the directory and its parent."
 143   (setq directory (file-name-as-directory directory))
 144   (let (results sub-results)
 145     (dolist (file (directory-files directory nil nil t))
 146       (let ((fullname (expand-file-name file directory)))
 147         (when (file-readable-p (expand-file-name file directory))
 148           ;; If a directory, check it we should descend into it
 149           (and (file-directory-p fullname)
 150                (funcall directory-predicate file directory)
 151                (progn
 152                  (setq sub-results
 153                        (find-lisp-find-files-internal
 154                         fullname
 155                         file-predicate
 156                         directory-predicate))
 157                  (if results
 158                      (nconc results sub-results)
 159                    (setq results sub-results))))
 160           ;; For all files and directories, call the file predicate
 161           (and (funcall file-predicate file directory)
 162                (if results
 163                    (nconc results (list fullname))
 164                  (setq results (list fullname)))))))
 165     results))
 166
 167 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 168 ;; Find-dired all in Lisp
 169 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 170
 171 ;;;###autoload
 172 (defun find-lisp-find-dired (dir regexp)
 173   "Find files in DIR, matching REGEXP."
 174   (interactive "DFind files in directory: \nsMatching regexp: ")
 175   (let ((find-lisp-regexp regexp))
 176     (find-lisp-find-dired-internal
 177      dir
 178      'find-lisp-default-file-predicate
 179      'find-lisp-default-directory-predicate
 180      "*Find Lisp Dired*")))
 181
 182 ;; Just the subdirectories
 183 ;;;###autoload
 184 (defun find-lisp-find-dired-subdirectories (dir)
 185   "Find all subdirectories of DIR."
 186   (interactive "DFind subdirectories of directory: ")
 187   (find-lisp-find-dired-internal
 188    dir
 189    'find-lisp-file-predicate-is-directory
 190    'find-lisp-default-directory-predicate
 191    "*Find Lisp Dired Subdirectories*"))
 192
 193 ;; Most of this is lifted from find-dired.el
 194 ;;
 195 (defun find-lisp-find-dired-internal (dir file-predicate
 196                                           directory-predicate buffer-name)
 197   "Run find (Lisp version) and go into Dired mode on a buffer of the output."
 198   (let ((dired-buffers dired-buffers)
 199         buf
 200         (regexp find-lisp-regexp))
 201     ;; Expand DIR ("" means default-directory), and make sure it has a
 202     ;; trailing slash.
 203     (setq dir (file-name-as-directory (expand-file-name dir)))
 204     ;; Check that it's really a directory.
 205     (or (file-directory-p dir)
 206         (error "find-dired needs a directory: %s" dir))
 207     (or
 208      (and (buffer-name)
 209           (string= buffer-name (buffer-name)))
 210         (switch-to-buffer (setq buf (get-buffer-create buffer-name))))
 211     (widen)
 212     (kill-all-local-variables)
 213     (setq buffer-read-only nil)
 214     (erase-buffer)
 215     (setq default-directory dir)
 216     (dired-mode dir)
 217
 218     (use-local-map (append (make-sparse-keymap) (current-local-map)))
 219
 220     (make-local-variable 'find-lisp-file-predicate)
 221     (setq find-lisp-file-predicate file-predicate)
 222     (make-local-variable 'find-lisp-directory-predicate)
 223     (setq find-lisp-directory-predicate directory-predicate)
 224     (make-local-variable 'find-lisp-regexp)
 225     (setq find-lisp-regexp regexp)
 226
 227     (make-local-variable 'revert-buffer-function)
 228     (setq revert-buffer-function
 229           (function
 230            (lambda(ignore1 ignore2)
 231              (find-lisp-insert-directory
 232               default-directory
 233               find-lisp-file-predicate
 234               find-lisp-directory-predicate
 235               'ignore)
 236              )
 237            ))
 238
 239     ;; Set subdir-alist so that Tree Dired will work:
 240     (if (fboundp 'dired-simple-subdir-alist)
 241         ;; will work even with nested dired format (dired-nstd.el,v 1.15
 242         ;; and later)
 243         (dired-simple-subdir-alist)
 244       ;; else we have an ancient tree dired (or classic dired, where
 245       ;; this does no harm)
 246       (set (make-local-variable 'dired-subdir-alist)
 247            (list (cons default-directory (point-min-marker)))))
 248     (find-lisp-insert-directory
 249      dir file-predicate directory-predicate 'ignore)
 250     (goto-char (point-min))
 251     (dired-goto-next-file)))
 252
 253 (defun find-lisp-insert-directory  (dir
 254                                     file-predicate
 255                                     directory-predicate
 256                                     sort-function)
 257   "Insert the results of `find-lisp-find-files' in the current buffer."
 258   (let ((buffer-read-only nil)
 259         (files (find-lisp-find-files-internal
 260                 dir
 261                 file-predicate
 262                 directory-predicate))
 263         (len (length dir)))
 264     (erase-buffer)
 265     ;; Subdir headlerline must come first because the first marker in
 266     ;; subdir-alist points there.
 267     (insert find-lisp-line-indent dir ":\n")
 268     ;; Make second line a ``find'' line in analogy to the ``total'' or
 269     ;; ``wildcard'' line.
 270     ;;
 271     ;; No analog for find-lisp?
 272     (insert find-lisp-line-indent "\n")
 273     ;; Run the find function
 274     (mapcar
 275      (function
 276       (lambda(file)
 277         (find-lisp-find-dired-insert-file
 278          (substring file len)
 279          (current-buffer))))
 280      (sort files 'string-lessp))
 281     ;; FIXME: Sort function is ignored for now
 282     ;; (funcall sort-function files))
 283     (goto-char (point-min))
 284     (dired-goto-next-file)))
 285
 286 ;;;###autoload
 287 (defun find-lisp-find-dired-filter (regexp)
 288   "Change the filter on a find-lisp-find-dired buffer to REGEXP."
 289   (interactive "sSet filter to regexp: ")
 290   (setq find-lisp-regexp regexp)
 291   (revert-buffer))
 292
 293 (defun find-lisp-find-dired-insert-file (file buffer)
 294   (set-buffer buffer)
 295   (insert find-lisp-line-indent
 296           (find-lisp-format file (file-attributes file 'string) (list "")
 297                           (current-time))))
 298
 299 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 300 ;; Lifted from ls-lisp. We don't want to require it, because that
 301 ;; would alter the insert-directory function.
 302 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 303
 304 (defun find-lisp-format (file-name file-attr switches now)
 305   (let ((file-type (nth 0 file-attr)))
 306     (concat (if (memq ?i switches)      ; inode number
 307                 (format "%6d " (nth 10 file-attr)))
 308             ;; nil is treated like "" in concat
 309             (if (memq ?s switches)      ; size in K
 310                 (format "%4d " (1+ (/ (nth 7 file-attr) 1024))))
 311             (nth 8 file-attr)           ; permission bits
 312             (format " %3d %-8s %-8s %8d "
 313                     (nth 1 file-attr)   ; no. of links
 314                     (if (numberp (nth 2 file-attr))
 315                         (int-to-string (nth 2 file-attr))
 316                       (nth 2 file-attr)) ; uid
 317                     (if (eq system-type 'ms-dos)
 318                         "root"          ; everything is root on MSDOS.
 319                       (if (numberp (nth 3 file-attr))
 320                           (int-to-string (nth 3 file-attr))
 321                         (nth 3 file-attr))) ; gid
 322                     (nth 7 file-attr)   ; size in bytes
 323                     )
 324             (find-lisp-format-time file-attr switches now)
 325             " "
 326             file-name
 327             (if (stringp file-type)     ; is a symbolic link
 328                 (concat " -> " file-type)
 329               "")
 330             "\n")))
 331
 332 (defun find-lisp-time-index (switches)
 333   ;; Return index into file-attributes according to ls SWITCHES.
 334   (cond
 335    ((memq ?c switches) 6)               ; last mode change
 336    ((memq ?u switches) 4)               ; last access
 337    ;; default is last modtime
 338    (t 5)))
 339
 340 (defun find-lisp-format-time (file-attr switches now)
 341   ;; Format time string for file with attributes FILE-ATTR according
 342   ;; to SWITCHES (a list of ls option letters of which c and u are recognized).
 343   ;; Use the same method as `ls' to decide whether to show time-of-day or year,
 344   ;; depending on distance between file date and NOW.
 345   (let* ((time (nth (find-lisp-time-index switches) file-attr))
 346          (diff16 (- (car time) (car now)))
 347          (diff (+ (ash diff16 16) (- (car (cdr time)) (car (cdr now)))))
 348          (past-cutoff (- (* 6 30 24 60 60)))    ; 6 30-day months
 349          (future-cutoff (* 60 60)))             ; 1 hour
 350     (format-time-string
 351      (if (and
 352           (<= past-cutoff diff) (<= diff future-cutoff)
 353           ;; Sanity check in case `diff' computation overflowed.
 354           (<= (1- (ash past-cutoff -16)) diff16)
 355           (<= diff16 (1+ (ash future-cutoff -16))))
 356          "%b %e %H:%M"
 357        "%b %e  %Y")
 358      time)))
 359
 360 (provide 'find-lisp)
 361
 362 ;;; arch-tag: a711374c-f12a-46f6-aa18-ba7d77b9602a
 363 ;;; find-lisp.el ends here