lisp/ls-lisp.el

   1 ;;; ls-lisp.el --- emulate insert-directory completely in Emacs Lisp
   2
   3 ;; Author: Sebastian Kremer <sk@thp.uni-koeln.de>
   4 ;; Keywords: unix
   5
   6 ;; Copyright (C) 1992 by Sebastian Kremer <sk@thp.uni-koeln.de>
   7
   8 ;; This program is free software; you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation; either version 1, or (at your option)
  11 ;; any later version.
  12 ;;
  13 ;; This program is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17 ;;
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with this program; if not, write to the Free Software
  20 ;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 ;; INSTALLATION =======================================================
  23 ;;
  24 ;; Put this file into your load-path.  To use it, load it
  25 ;; with (load "directory").
  26
  27 ;; OVERVIEW ===========================================================
  28
  29 ;; This file overloads the function insert-directory to implement it
  30 ;; directly from Emacs lisp, without running `ls' in a subprocess.
  31
  32 ;; It is useful if you cannot afford to fork Emacs on a real memory UNIX,
  33 ;; under VMS, or if you don't have the ls program, or if you want
  34 ;; different format from what ls offers.
  35
  36 ;; This function uses regexps instead of shell
  37 ;; wildcards.  If you enter regexps remember to double each $ sign.
  38 ;; For example, to include files *.el, enter `.*\.el$$',
  39 ;; resulting in the regexp `.*\.el$'.
  40
  41 ;;  RESTRICTIONS =====================================================
  42
  43 ;; * many ls switches are ignored, see docstring of `insert-directory'.
  44
  45 ;; * Only numeric uid/gid
  46
  47 ;; TODO ==============================================================
  48
  49 ;; Recognize some more ls switches: R F
  50 \f
  51 ;;; Code:
  52
  53 (defun insert-directory (file &optional switches wildcard full-directory-p)
  54   "Insert directory listing for of FILE, formatted according to SWITCHES.
  55 Leaves point after the inserted text.
  56 Optional third arg WILDCARD means treat FILE as shell wildcard.
  57 Optional fourth arg FULL-DIRECTORY-P means file is a directory and
  58 switches do not contain `d', so that a full listing is expected.
  59
  60 This version of the function comes from `directory.el'.
  61 It does not support ordinary shell wildcards; instead, it allows
  62 regular expressions to match file names.
  63
  64 The switches that work are: A a c i r S s t u"
  65   (let (handler ((find-file-name-handler file)))
  66     (if handler
  67         (funcall handler 'insert-directory file switches
  68                  wildcard full-directory-p)
  69       (if wildcard
  70           (setq wildcard (file-name-nondirectory file) ; actually emacs regexp
  71                 ;; perhaps convert it from shell to emacs syntax?
  72                 file (file-name-directory file)))
  73       (if (or wildcard
  74               full-directory-p)
  75           (let* ((dir (file-name-as-directory file))
  76                  (default-directory dir);; so that file-attributes works
  77                  (sum 0)
  78                  elt
  79                  short
  80                  (file-list (directory-files dir nil wildcard))
  81                  file-alist
  82                  ;; do all bindings here for speed
  83                  fil attr)
  84             (cond ((memq ?A switches)
  85                    (setq file-list
  86                          (ls-lisp-delete-matching "^\\.\\.?$" file-list)))
  87                   ((not (memq ?a switches))
  88                    ;; if neither -A  nor -a, flush . files
  89                    (setq file-list
  90                          (ls-lisp-delete-matching "^\\." file-list))))
  91             (setq file-alist
  92                   (mapcar
  93                    (function
  94                     (lambda (x)
  95                       ;; file-attributes("~bogus") bombs
  96                       (cons x (file-attributes (expand-file-name x)))))
  97                    ;; inserting the call to directory-files right here
  98                    ;; seems to stimulate an Emacs bug
  99                    ;; ILLEGAL DATATYPE (#o37777777727) or #o67
 100                    file-list))
 101             (insert "total \007\n")     ; filled in afterwards
 102             (setq file-alist
 103                   (ls-lisp-handle-switches file-alist switches))
 104             (while file-alist
 105               (setq elt (car file-alist)
 106                     short (car elt)
 107                     attr  (cdr elt)
 108                     file-alist (cdr file-alist)
 109                     fil (concat dir short)
 110                     sum (+ sum (nth 7 attr)))
 111               (insert (ls-lisp-format short attr switches)))
 112             ;; Fill in total size of all files:
 113             (save-excursion
 114               (search-backward "total \007")
 115               (goto-char (match-end 0))
 116               (delete-char -1)
 117               (insert (format "%d" (1+ (/ sum 1024))))))
 118         ;; if not full-directory-p, FILE *must not* end in /, as
 119         ;; file-attributes will not recognize a symlink to a directory
 120         ;; must make it a relative filename as ls does:
 121         (setq file (file-name-nondirectory file))
 122         (insert (ls-lisp-format file (file-attributes file) switches))))))
 123
 124 (defun ls-lisp-delete-matching (regexp list)
 125   ;; Delete all elements matching REGEXP from LIST, return new list.
 126   ;; Should perhaps use setcdr for efficiency.
 127   (let (result)
 128     (while list
 129       (or (string-match regexp (car list))
 130           (setq result (cons (car list) result)))
 131       (setq list (cdr list)))
 132     result))
 133
 134 (defun ls-lisp-handle-switches (file-alist switches)
 135   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
 136   ;; Return new alist sorted according to SWITCHES which is a list of
 137   ;; characters.  Default sorting is alphabetically.
 138   (let (index)
 139     (setq file-alist
 140           (sort file-alist
 141                 (cond ((memq ?S switches) ; sorted on size
 142                        (function
 143                         (lambda (x y)
 144                           ;; 7th file attribute is file size
 145                           ;; Make largest file come first
 146                           (< (nth 7 (cdr y))
 147                              (nth 7 (cdr x))))))
 148                       ((memq ?t switches) ; sorted on time
 149                        (setq index (ls-lisp-time-index switches))
 150                        (function
 151                         (lambda (x y)
 152                           (ls-lisp-time-lessp (nth index (cdr y))
 153                                               (nth index (cdr x))))))
 154                       (t                ; sorted alphabetically
 155                        (function
 156                         (lambda (x y)
 157                           (string-lessp (car x)
 158                                         (car y)))))))))
 159   (if (memq ?r switches)                ; reverse sort order
 160       (setq file-alist (nreverse file-alist)))
 161   file-alist)
 162
 163 ;; From Roland McGrath.  Can use this to sort on time.
 164 (defun ls-lisp-time-lessp (time0 time1)
 165   (let ((hi0 (car time0))
 166         (hi1 (car time1))
 167         (lo0 (car (cdr time0)))
 168         (lo1 (car (cdr time1))))
 169     (or (< hi0 hi1)
 170         (and (= hi0 hi1)
 171              (< lo0 lo1)))))
 172
 173
 174 (defun ls-lisp-format (file-name file-attr &optional switches)
 175   (let ((file-type (nth 0 file-attr)))
 176     (concat (if (memq ?i switches)      ; inode number
 177                 (format "%6d " (nth 10 file-attr)))
 178             ;; nil is treated like "" in concat
 179             (if (memq ?s switches)      ; size in K
 180                 (format "%4d " (1+ (/ (nth 7 file-attr) 1024))))
 181             (nth 8 file-attr)           ; permission bits
 182             ;; numeric uid/gid are more confusing than helpful
 183             ;; Emacs should be able to make strings of them.
 184             ;; user-login-name and user-full-name could take an
 185             ;; optional arg.
 186             (format " %3d %-8d %-8d %8d "
 187                     (nth 1 file-attr)   ; no. of links
 188                     (nth 2 file-attr)   ; uid
 189                     (nth 3 file-attr)   ; gid
 190                     (nth 7 file-attr)   ; size in bytes
 191                     )
 192             (ls-lisp-format-time file-attr switches)
 193             " "
 194             file-name
 195             (if (stringp file-type)     ; is a symbolic link
 196                 (concat " -> " file-type)
 197               "")
 198             "\n"
 199             )))
 200
 201 (defun ls-lisp-time-index (switches)
 202   ;; Return index into file-attributes according to ls SWITCHES.
 203   (cond
 204    ((memq ?c switches) 6)               ; last mode change
 205    ((memq ?u switches) 4)               ; last access
 206    ;; default is last modtime
 207    (t 5)))
 208
 209 (defun ls-lisp-format-time (file-attr switches)
 210   ;; Format time string for file with attributes FILE-ATTR according
 211   ;; to SWITCHES (a list of ls option letters of which c and u are recognized).
 212   ;; file-attributes's time is in a braindead format
 213   ;; Emacs 19 can format it using a new optional argument to
 214   ;; current-time-string, for Emacs 18 we just return the faked fixed
 215   ;; date "Jan 00 00:00 ".
 216   (condition-case error-data
 217       (let* ((time (current-time-string
 218                     (nth (ls-lisp-time-index switches) file-attr)))
 219              (date (substring time 4 11)) ; "Apr 30 "
 220              (clock (substring time 11 16)) ; "11:27"
 221              (year (substring time 19 24)) ; " 1992"
 222              (same-year (equal year (substring (current-time-string) 19 24))))
 223         (concat date                    ; has trailing SPC
 224                 (if same-year
 225                     ;; this is not exactly the same test used by ls
 226                     ;; ls tests if the file is older than 6 months
 227                     ;; but we can't do time differences easily
 228                     clock
 229                   year)))
 230     (error
 231      "Jan 00 00:00")))
 232
 233 (provide 'ls-lisp)
 234
 235 ;;; ls-lisp.el ends here