lisp/ls-lisp.el

   1 ;;; ls-lisp.el --- emulate insert-directory completely in Emacs Lisp
   2
   3 ;; Copyright (C) 1992, 1994, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
   4 ;;   2007, 2008, 2009, 2010  Free Software Foundation, Inc.
   5
   6 ;; Author: Sebastian Kremer <sk@thp.uni-koeln.de>
   7 ;; Modified by: Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>
   8 ;; Maintainer: FSF
   9 ;; Keywords: unix, dired
  10 ;; Package: emacs
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28
  29 ;; OVERVIEW ==========================================================
  30
  31 ;; This file redefines the function `insert-directory' to implement it
  32 ;; directly from Emacs lisp, without running ls in a subprocess.  It
  33 ;; is useful if you cannot afford to fork Emacs on a real memory UNIX,
  34 ;; or other non-UNIX platforms if you don't have the ls
  35 ;; program, or if you want a different format from what ls offers.
  36
  37 ;; This function can use regexps instead of shell wildcards.  If you
  38 ;; enter regexps remember to double each $ sign.  For example, to
  39 ;; include files *.el, enter `.*\.el$$', resulting in the regexp
  40 ;; `.*\.el$'.
  41
  42 ;; RESTRICTIONS ======================================================
  43
  44 ;; * A few obscure ls switches are still ignored: see the docstring of
  45 ;; `insert-directory'.
  46
  47 ;; TO DO =============================================================
  48
  49 ;; Complete handling of F switch (if/when possible).
  50
  51 ;; FJW: May be able to sort much faster by consing the sort key onto
  52 ;; the front of each list element, sorting and then stripping the key
  53 ;; off again!
  54
  55 ;;; History:
  56
  57 ;; Written originally by Sebastian Kremer <sk@thp.uni-koeln.de>
  58 ;; Revised by Andrew Innes and Geoff Volker (and maybe others).
  59
  60 ;; Modified by Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>, mainly
  61 ;; to support many more ls options, "platform emulation" and more
  62 ;; robust sorting.
  63
  64 ;;; Code:
  65
  66 (eval-when-compile (require 'cl))
  67
  68 (defgroup ls-lisp nil
  69   "Emulate the ls program completely in Emacs Lisp."
  70   :version "21.1"
  71   :group 'dired)
  72
  73 (defcustom ls-lisp-emulation
  74   (cond ;; ((eq system-type 'windows-nt) 'MS-Windows)
  75         ((memq system-type
  76                '(hpux usg-unix-v irix berkeley-unix))
  77          'UNIX))                        ; very similar to GNU
  78   ;; Anything else defaults to nil, meaning GNU.
  79   "Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
  80 Corresponding value is one of the atoms: nil, MacOS, MS-Windows, UNIX.
  81 Sets default values for: `ls-lisp-ignore-case', `ls-lisp-dirs-first',
  82 `ls-lisp-verbosity'.  Need not match actual platform.  Changing this
  83 option will have no effect until you restart Emacs."
  84   :type '(choice (const :tag "GNU" nil)
  85                  (const MacOS)
  86                  (const MS-Windows)
  87                  (const UNIX))
  88   :group 'ls-lisp)
  89
  90 (defcustom ls-lisp-ignore-case
  91   ;; Name change for consistency with other option names.
  92   (or (memq ls-lisp-emulation '(MS-Windows MacOS))
  93       (and (boundp 'ls-lisp-dired-ignore-case) ls-lisp-dired-ignore-case))
  94   "Non-nil causes ls-lisp alphabetic sorting to ignore case."
  95   :type 'boolean
  96   :group 'ls-lisp)
  97
  98 (defcustom ls-lisp-dirs-first (eq ls-lisp-emulation 'MS-Windows)
  99   "Non-nil causes ls-lisp to sort directories first in any ordering.
 100 \(Or last if it is reversed.)  Follows Microsoft Windows Explorer."
 101   ;; Functionality suggested by Chris McMahan <cmcmahan@one.net>
 102   :type 'boolean
 103   :group 'ls-lisp)
 104
 105 (defcustom ls-lisp-verbosity
 106   (cond ((eq ls-lisp-emulation 'MacOS) nil)
 107         ((eq ls-lisp-emulation 'MS-Windows)
 108          (if (and (fboundp 'w32-using-nt) (w32-using-nt))
 109              '(links)))                 ; distinguish NT/2K from 9x
 110         ((eq ls-lisp-emulation 'UNIX) '(links uid)) ; UNIX ls
 111         (t '(links uid gid)))           ; GNU ls
 112   "A list of optional file attributes that ls-lisp should display.
 113 It should contain none or more of the symbols: links, uid, gid.
 114 A value of nil (or an empty list) means display none of them.
 115
 116 Concepts come from UNIX: `links' means count of names associated with
 117 the file\; `uid' means user (owner) identifier\; `gid' means group
 118 identifier.
 119
 120 If emulation is MacOS then default is nil\;
 121 if emulation is MS-Windows then default is `(links)' if platform is
 122 Windows NT/2K, nil otherwise\;
 123 if emulation is UNIX then default is `(links uid)'\;
 124 if emulation is GNU then default is `(links uid gid)'."
 125   ;; Functionality suggested by Howard Melman <howard@silverstream.com>
 126   :type '(set (const :tag "Show Link Count" links)
 127               (const :tag "Show User" uid)
 128               (const :tag "Show Group" gid))
 129   :group 'ls-lisp)
 130
 131 (defcustom ls-lisp-use-insert-directory-program
 132   (not (memq system-type '(ms-dos windows-nt)))
 133   "Non-nil causes ls-lisp to revert back to using `insert-directory-program'.
 134 This is useful on platforms where ls-lisp is dumped into Emacs, such as
 135 Microsoft Windows, but you would still like to use a program to list
 136 the contents of a directory."
 137   :type 'boolean
 138   :group 'ls-lisp)
 139
 140 ;;; Autoloaded because it is let-bound in `recover-session', `mail-recover-1'.
 141 ;;;###autoload
 142 (defcustom ls-lisp-support-shell-wildcards t
 143   "Non-nil means ls-lisp treats file patterns as shell wildcards.
 144 Otherwise they are treated as Emacs regexps (for backward compatibility)."
 145   :type 'boolean
 146   :group 'ls-lisp)
 147
 148 (defcustom ls-lisp-format-time-list
 149   '("%b %e %H:%M"
 150     "%b %e  %Y")
 151   "List of `format-time-string' specs to display file time stamps.
 152 These specs are used ONLY if a valid locale can not be determined.
 153
 154 If `ls-lisp-use-localized-time-format' is non-nil, these specs are used
 155 regardless of whether the locale can be determined.
 156
 157 Syntax:  (EARLY-TIME-FORMAT OLD-TIME-FORMAT)
 158
 159 The EARLY-TIME-FORMAT is used if file has been modified within the
 160 current year. The OLD-TIME-FORMAT is used for older files.  To use ISO
 161 8601 dates, you could set:
 162
 163 \(setq ls-lisp-format-time-list
 164        '(\"%Y-%m-%d %H:%M\"
 165          \"%Y-%m-%d      \"))"
 166   :type '(list (string :tag "Early time format")
 167                (string :tag "Old time format"))
 168   :group 'ls-lisp)
 169
 170 (defcustom ls-lisp-use-localized-time-format nil
 171   "Non-nil causes ls-lisp to use `ls-lisp-format-time-list' even if
 172 a valid locale is specified.
 173
 174 WARNING: Using localized date/time format might cause Dired columns
 175 to fail to lign up, e.g. if month names are not all of the same length."
 176   :type 'boolean
 177   :group 'ls-lisp)
 178
 179 (defvar original-insert-directory nil
 180   "This holds the original function definition of `insert-directory'.")
 181
 182 (defvar ls-lisp-uid-d-fmt "-%d"
 183   "Format to display integer UIDs.")
 184 (defvar ls-lisp-uid-s-fmt "-%s"
 185   "Format to display user names.")
 186 (defvar ls-lisp-gid-d-fmt "-%d"
 187   "Format to display integer GIDs.")
 188 (defvar ls-lisp-gid-s-fmt "-%s"
 189   "Format to display user group names.")
 190 (defvar ls-lisp-filesize-d-fmt "%d"
 191   "Format to display integer file sizes.")
 192 (defvar ls-lisp-filesize-f-fmt "%.0f"
 193   "Format to display float file sizes.")
 194
 195 ;; Remember the original insert-directory function
 196 (or (featurep 'ls-lisp)  ; FJW: unless this file is being reloaded!
 197     (setq original-insert-directory (symbol-function 'insert-directory)))
 198
 199 \f
 200 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 201
 202 (defun insert-directory (file switches &optional wildcard full-directory-p)
 203   "Insert directory listing for FILE, formatted according to SWITCHES.
 204 Leaves point after the inserted text.
 205 SWITCHES may be a string of options, or a list of strings.
 206 Optional third arg WILDCARD means treat FILE as shell wildcard.
 207 Optional fourth arg FULL-DIRECTORY-P means file is a directory and
 208 switches do not contain `d', so that a full listing is expected.
 209
 210 This version of the function comes from `ls-lisp.el'.
 211 If the value of `ls-lisp-use-insert-directory-program' is non-nil then
 212 it works exactly like the version from `files.el' and runs a directory
 213 listing program whose name is in the variable
 214 `insert-directory-program'; if also WILDCARD is non-nil then it runs
 215 the shell specified by `shell-file-name'.  If the value of
 216 `ls-lisp-use-insert-directory-program' is nil then it runs a Lisp
 217 emulation.
 218
 219 The Lisp emulation does not run any external programs or shells.  It
 220 supports ordinary shell wildcards if `ls-lisp-support-shell-wildcards'
 221 is non-nil; otherwise, it interprets wildcards as regular expressions
 222 to match file names.  It does not support all `ls' switches -- those
 223 that work are: A a B C c F G g h i n R r S s t U u X.  The l switch
 224 is assumed to be always present and cannot be turned off."
 225   (if ls-lisp-use-insert-directory-program
 226       (funcall original-insert-directory
 227                file switches wildcard full-directory-p)
 228     ;; We need the directory in order to find the right handler.
 229     (let ((handler (find-file-name-handler (expand-file-name file)
 230                                            'insert-directory))
 231           (orig-file file)
 232           wildcard-regexp)
 233       (if handler
 234           (funcall handler 'insert-directory file switches
 235                    wildcard full-directory-p)
 236         ;; Remove --dired switch
 237         (if (string-match "--dired " switches)
 238             (setq switches (replace-match "" nil nil switches)))
 239         ;; Convert SWITCHES to a list of characters.
 240         (setq switches (delete ?\  (delete ?- (append switches nil))))
 241         ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
 242         ;; `ls' don't mind, we certainly do, because it makes us think
 243         ;; there is no wildcard, only a directory name.
 244         (if (and ls-lisp-support-shell-wildcards
 245                  (string-match "[[?*]" file)
 246                  ;; Prefer an existing file to wildcards, like
 247                  ;; dired-noselect does.
 248                  (not (file-exists-p file)))
 249             (progn
 250               (or (not (eq (aref file (1- (length file))) ?/))
 251                   (setq file (substring file 0 (1- (length file)))))
 252               (setq wildcard t)))
 253         (if wildcard
 254             (setq wildcard-regexp
 255                   (if ls-lisp-support-shell-wildcards
 256                       (wildcard-to-regexp (file-name-nondirectory file))
 257                     (file-name-nondirectory file))
 258                   file (file-name-directory file))
 259           (if (memq ?B switches) (setq wildcard-regexp "[^~]\\'")))
 260         (condition-case err
 261             (ls-lisp-insert-directory
 262              file switches (ls-lisp-time-index switches)
 263              wildcard-regexp full-directory-p)
 264           (invalid-regexp
 265            ;; Maybe they wanted a literal file that just happens to
 266            ;; use characters special to shell wildcards.
 267            (if (equal (cadr err) "Unmatched [ or [^")
 268                (progn
 269                  (setq wildcard-regexp (if (memq ?B switches) "[^~]\\'")
 270                        file (file-relative-name orig-file))
 271                  (ls-lisp-insert-directory
 272                   file switches (ls-lisp-time-index switches)
 273                   nil full-directory-p))
 274              (signal (car err) (cdr err)))))
 275         ;; Try to insert the amount of free space.
 276         (save-excursion
 277           (goto-char (point-min))
 278           ;; First find the line to put it on.
 279           (when (re-search-forward "^total" nil t)
 280             (let ((available (get-free-disk-space ".")))
 281               (when available
 282                 ;; Replace "total" with "total used", to avoid confusion.
 283                 (replace-match "total used in directory")
 284                 (end-of-line)
 285                 (insert " available " available)))))))))
 286
 287 (defun ls-lisp-insert-directory
 288   (file switches time-index wildcard-regexp full-directory-p)
 289   "Insert directory listing for FILE, formatted according to SWITCHES.
 290 Leaves point after the inserted text.  This is an internal function
 291 optionally called by the `ls-lisp.el' version of `insert-directory'.
 292 It is called recursively if the -R switch is used.
 293 SWITCHES is a *list* of characters.  TIME-INDEX is the time index into
 294 file-attributes according to SWITCHES.  WILDCARD-REGEXP is nil or an *Emacs
 295 regexp*.  FULL-DIRECTORY-P means file is a directory and SWITCHES does
 296 not contain `d', so that a full listing is expected."
 297   (if (or wildcard-regexp full-directory-p)
 298       (let* ((dir (file-name-as-directory file))
 299              (default-directory dir)    ; so that file-attributes works
 300              (file-alist
 301               (directory-files-and-attributes dir nil wildcard-regexp t
 302                                               (if (memq ?n switches)
 303                                                   'integer
 304                                                 'string)))
 305              (now (current-time))
 306              (sum 0)
 307              (max-uid-len 0)
 308              (max-gid-len 0)
 309              (max-file-size 0)
 310              ;; do all bindings here for speed
 311              total-line files elt short file-size fil attr
 312              fuid fgid uid-len gid-len)
 313         (cond ((memq ?A switches)
 314                (setq file-alist
 315                      (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
 316               ((not (memq ?a switches))
 317                ;; if neither -A  nor -a, flush . files
 318                (setq file-alist
 319                      (ls-lisp-delete-matching "^\\." file-alist))))
 320         (setq file-alist
 321               (ls-lisp-handle-switches file-alist switches))
 322         (if (memq ?C switches)          ; column (-C) format
 323             (ls-lisp-column-format file-alist)
 324           (setq total-line (cons (point) (car-safe file-alist)))
 325           ;; Find the appropriate format for displaying uid, gid, and
 326           ;; file size, by finding the longest strings among all the
 327           ;; files we are about to display.
 328           (dolist (elt file-alist)
 329             (setq attr (cdr elt)
 330                   fuid (nth 2 attr)
 331                   uid-len (if (stringp fuid) (string-width fuid)
 332                             (length (format "%d" fuid)))
 333                   fgid (nth 3 attr)
 334                   gid-len (if (stringp fgid) (string-width fgid)
 335                             (length (format "%d" fgid)))
 336                   file-size (nth 7 attr))
 337             (if (> uid-len max-uid-len)
 338                 (setq max-uid-len uid-len))
 339             (if (> gid-len max-gid-len)
 340                 (setq max-gid-len gid-len))
 341             (if (> file-size max-file-size)
 342                 (setq max-file-size file-size)))
 343           (setq ls-lisp-uid-d-fmt (format " %%-%dd" max-uid-len))
 344           (setq ls-lisp-uid-s-fmt (format " %%-%ds" max-uid-len))
 345           (setq ls-lisp-gid-d-fmt (format " %%-%dd" max-gid-len))
 346           (setq ls-lisp-gid-s-fmt (format " %%-%ds" max-gid-len))
 347           (setq ls-lisp-filesize-d-fmt
 348                 (format " %%%dd"
 349                         (if (memq ?s switches)
 350                             (length (format "%.0f"
 351                                             (fceiling (/ max-file-size 1024.0))))
 352                           (length (format "%.0f" max-file-size)))))
 353           (setq ls-lisp-filesize-f-fmt
 354                 (format " %%%d.0f"
 355                         (if (memq ?s switches)
 356                             (length (format "%.0f"
 357                                             (fceiling (/ max-file-size 1024.0))))
 358                           (length (format "%.0f" max-file-size)))))
 359           (setq files file-alist)
 360           (while files                  ; long (-l) format
 361             (setq elt (car files)
 362                   files (cdr files)
 363                   short (car elt)
 364                   attr (cdr elt)
 365                   file-size (nth 7 attr))
 366             (and attr
 367                  (setq sum (+ file-size
 368                               ;; Even if neither SUM nor file's size
 369                               ;; overflow, their sum could.
 370                               (if (or (< sum (- 134217727 file-size))
 371                                       (floatp sum)
 372                                       (floatp file-size))
 373                                   sum
 374                                 (float sum))))
 375                  (insert (ls-lisp-format short attr file-size
 376                                          switches time-index now))))
 377           ;; Insert total size of all files:
 378           (save-excursion
 379             (goto-char (car total-line))
 380             (or (cdr total-line)
 381                 ;; Shell says ``No match'' if no files match
 382                 ;; the wildcard; let's say something similar.
 383                 (insert "(No match)\n"))
 384             (insert (format "total %.0f\n" (fceiling (/ sum 1024.0))))))
 385         (if (memq ?R switches)
 386             ;; List the contents of all directories recursively.
 387             ;; cadr of each element of `file-alist' is t for
 388             ;; directory, string (name linked to) for symbolic
 389             ;; link, or nil.
 390             (while file-alist
 391               (setq elt (car file-alist)
 392                     file-alist (cdr file-alist))
 393               (when (and (eq (cadr elt) t) ; directory
 394                          ;; Under -F, we have already decorated all
 395                          ;; directories, including "." and "..", with
 396                          ;; a /, so allow for that as well.
 397                          (not (string-match "\\`\\.\\.?/?\\'" (car elt))))
 398                 (setq elt (expand-file-name (car elt) dir))
 399                 (insert "\n" elt ":\n")
 400                 (ls-lisp-insert-directory
 401                  elt switches time-index wildcard-regexp full-directory-p)))))
 402     ;; If not full-directory-p, FILE *must not* end in /, as
 403     ;; file-attributes will not recognize a symlink to a directory,
 404     ;; so must make it a relative filename as ls does:
 405     (if (file-name-absolute-p file) (setq file (expand-file-name file)))
 406     (if (eq (aref file (1- (length file))) ?/)
 407         (setq file (substring file 0 -1)))
 408     (let ((fattr (file-attributes file 'string)))
 409       (if fattr
 410           (insert (ls-lisp-format
 411                    (if (memq ?F switches)
 412                        (ls-lisp-classify-file file fattr)
 413                      file)
 414                    fattr (nth 7 fattr)
 415                                   switches time-index (current-time)))
 416         (message "%s: doesn't exist or is inaccessible" file)
 417         (ding) (sit-for 2)))))          ; to show user the message!
 418
 419 (defun ls-lisp-column-format (file-alist)
 420   "Insert the file names (only) in FILE-ALIST into the current buffer.
 421 Format in columns, sorted vertically, following GNU ls -C.
 422 Responds to the window width as ls should but may not!"
 423   (let (files fmt ncols collen (nfiles 0) (colwid 0))
 424     ;; Count number of files as `nfiles', build list of filenames as
 425     ;; `files', and find maximum filename length as `colwid':
 426     (let (file len)
 427       (while file-alist
 428         (setq nfiles (1+ nfiles)
 429               file (caar file-alist)
 430               files (cons file files)
 431               file-alist (cdr file-alist)
 432               len (length file))
 433         (if (> len colwid) (setq colwid len))))
 434     (setq files (nreverse files)
 435           colwid (+ 2 colwid)           ; 2 character column gap
 436           fmt (format "%%-%ds" colwid)  ; print format
 437           ncols (/ (window-width) colwid) ; no of columns
 438           collen (/ nfiles ncols))      ; floor of column length
 439     (if (> nfiles (* collen ncols)) (setq collen (1+ collen)))
 440     ;; Output the file names in columns, sorted vertically:
 441     (let ((i 0) j)
 442       (while (< i collen)
 443         (setq j i)
 444         (while (< j nfiles)
 445           (insert (format fmt (nth j files)))
 446           (setq j (+ j collen)))
 447         ;; FJW: This is completely unnecessary, but I don't like
 448         ;; trailing white space...
 449         (delete-region (point) (progn (skip-chars-backward " \t") (point)))
 450         (insert ?\n)
 451         (setq i (1+ i))))))
 452
 453 (defun ls-lisp-delete-matching (regexp list)
 454   "Delete all elements matching REGEXP from LIST, return new list."
 455   ;; Should perhaps use setcdr for efficiency.
 456   (let (result)
 457     (while list
 458       (or (string-match regexp (caar list))
 459           (setq result (cons (car list) result)))
 460       (setq list (cdr list)))
 461     result))
 462
 463 (defsubst ls-lisp-string-lessp (s1 s2)
 464   "Return t if string S1 is less than string S2 in lexicographic order.
 465 Case is significant if `ls-lisp-ignore-case' is nil.
 466 Unibyte strings are converted to multibyte for comparison."
 467   (let ((u (compare-strings s1 0 nil s2 0 nil ls-lisp-ignore-case)))
 468     (and (numberp u) (< u 0))))
 469
 470 (defun ls-lisp-handle-switches (file-alist switches)
 471   "Return new FILE-ALIST sorted according to SWITCHES.
 472 SWITCHES is a list of characters.  Default sorting is alphabetic."
 473   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
 474   (or (memq ?U switches)                ; unsorted
 475       ;; Catch and ignore unexpected sorting errors
 476       (condition-case err
 477           (setq file-alist
 478                 (let (index)
 479                   ;; Copy file-alist in case of error
 480                   (sort (copy-sequence file-alist) ; modifies its argument!
 481                         (cond ((memq ?S switches)
 482                                (lambda (x y) ; sorted on size
 483                                  ;; 7th file attribute is file size
 484                                  ;; Make largest file come first
 485                                  (< (nth 7 (cdr y))
 486                                     (nth 7 (cdr x)))))
 487                               ((setq index (ls-lisp-time-index switches))
 488                                (lambda (x y) ; sorted on time
 489                                  (time-less-p (nth index (cdr y))
 490                                               (nth index (cdr x)))))
 491                               ((memq ?X switches)
 492                                (lambda (x y) ; sorted on extension
 493                                  (ls-lisp-string-lessp
 494                                   (ls-lisp-extension (car x))
 495                                   (ls-lisp-extension (car y)))))
 496                               (t
 497                                (lambda (x y) ; sorted alphabetically
 498                                  (ls-lisp-string-lessp (car x) (car y))))))))
 499         (error (message "Unsorted (ls-lisp sorting error) - %s"
 500                         (error-message-string err))
 501                (ding) (sit-for 2))))    ; to show user the message!
 502   (if (memq ?F switches)                ; classify switch
 503       (setq file-alist (mapcar 'ls-lisp-classify file-alist)))
 504   (if ls-lisp-dirs-first
 505   ;; Re-sort directories first, without otherwise changing the
 506   ;; ordering, and reverse whole list.  cadr of each element of
 507   ;; `file-alist' is t for directory, string (name linked to) for
 508   ;; symbolic link, or nil.
 509       (let (el dirs files)
 510         (while file-alist
 511           (if (or (eq (cadr (setq el (car file-alist))) t) ; directory
 512                   (and (stringp (cadr el))
 513                        (file-directory-p (cadr el)))) ; symlink to a directory
 514               (setq dirs (cons el dirs))
 515             (setq files (cons el files)))
 516           (setq file-alist (cdr file-alist)))
 517         (setq file-alist
 518               (if (memq ?U switches)    ; unsorted order is reversed
 519                   (nconc dirs files)
 520                 (nconc files dirs)
 521                 ))))
 522   ;; Finally reverse file alist if necessary.
 523   ;; (eq below MUST compare `(not (memq ...))' to force comparison of
 524   ;; `t' or `nil', rather than list tails!)
 525   (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
 526               (not (memq ?r switches))) ; reversed sort order requested
 527           ls-lisp-dirs-first)           ; already reversed
 528       (nreverse file-alist)
 529     file-alist))
 530
 531 (defun ls-lisp-classify-file (filename fattr)
 532   "Append a character to FILENAME indicating the file type.
 533
 534 FATTR is the file attributes returned by `file-attributes' for the file.
 535 The file type indicators are `/' for directories, `@' for symbolic
 536 links, `|' for FIFOs, `=' for sockets, `*' for regular files that
 537 are executable, and nothing for other types of files."
 538   (let* ((type (car fattr))
 539          (modestr (nth 8 fattr))
 540          (typestr (substring modestr 0 1)))
 541     (cond
 542      (type
 543       (concat filename (if (eq type t) "/" "@")))
 544      ((string-match "x" modestr)
 545       (concat filename "*"))
 546      ((string= "p" typestr)
 547       (concat filename "|"))
 548      ((string= "s" typestr)
 549       (concat filename "="))
 550      (t filename))))
 551
 552 (defun ls-lisp-classify (filedata)
 553   "Append a character to file name in FILEDATA indicating the file type.
 554
 555 FILEDATA has the form (FILENAME . ATTRIBUTES), where ATTRIBUTES is the
 556 structure returned by `file-attributes' for that file.
 557
 558 The file type indicators are `/' for directories, `@' for symbolic
 559 links, `|' for FIFOs, `=' for sockets, `*' for regular files that
 560 are executable, and nothing for other types of files."
 561   (let ((file-name (car filedata))
 562         (fattr (cdr filedata)))
 563     (setq file-name (propertize file-name 'dired-filename t))
 564     (cons (ls-lisp-classify-file file-name fattr) fattr)))
 565
 566 (defun ls-lisp-extension (filename)
 567   "Return extension of FILENAME (ignoring any version extension)
 568 FOLLOWED by null and full filename, SOLELY for full alpha sort."
 569   ;; Force extension sort order: `no ext' then `null ext' then `ext'
 570   ;; to agree with GNU ls.
 571   (concat
 572    (let* ((i (length filename)) end)
 573      (if (= (aref filename (1- i)) ?.) ; null extension
 574          "\0"
 575        (while (and (>= (setq i (1- i)) 0)
 576                    (/= (aref filename i) ?.)))
 577        (if (< i 0) "\0\0"               ; no extension
 578          (if (/= (aref filename (1+ i)) ?~)
 579              (substring filename (1+ i))
 580            ;; version extension found -- ignore it
 581            (setq end i)
 582            (while (and (>= (setq i (1- i)) 0)
 583                        (/= (aref filename i) ?.)))
 584            (if (< i 0) "\0\0"   ; no extension
 585              (substring filename (1+ i) end))))
 586        )) "\0" filename))
 587
 588 (defun ls-lisp-format (file-name file-attr file-size switches time-index now)
 589   "Format one line of long ls output for file FILE-NAME.
 590 FILE-ATTR and FILE-SIZE give the file's attributes and size.
 591 SWITCHES, TIME-INDEX and NOW give the full switch list and time data."
 592   (let ((file-type (nth 0 file-attr))
 593         ;; t for directory, string (name linked to)
 594         ;; for symbolic link, or nil.
 595         (drwxrwxrwx (nth 8 file-attr))) ; attribute string ("drwxrwxrwx")
 596     (concat (if (memq ?i switches)      ; inode number
 597                 (let ((inode (nth 10 file-attr)))
 598                   (if (consp inode)
 599                       (if (consp (cdr inode))
 600                           ;; 2^(24+16) = 1099511627776.0, but
 601                           ;; multiplying by it and then adding the
 602                           ;; other members of the cons cell in one go
 603                           ;; loses precision, since a double does not
 604                           ;; have enough significant digits to hold a
 605                           ;; full 64-bit value.  So below we split
 606                           ;; 1099511627776 into high 13 and low 5
 607                           ;; digits and compute in two parts.
 608                           (let ((p1 (* (car inode) 10995116.0))
 609                                 (p2 (+ (* (car inode) 27776.0)
 610                                        (* (cadr inode) 65536.0)
 611                                        (cddr inode))))
 612                             (format " %13.0f%05.0f "
 613                                     ;; Use floor to emulate integer
 614                                     ;; division.
 615                                     (+ p1 (floor p2 100000.0))
 616                                     (mod p2 100000.0)))
 617                         (format " %18.0f "
 618                                 (+ (* (car inode) 65536.0)
 619                                    (cdr inode))))
 620                     (format " %18d " inode))))
 621             ;; nil is treated like "" in concat
 622             (if (memq ?s switches)      ; size in K
 623                 (format ls-lisp-filesize-f-fmt
 624                         (fceiling (/ file-size 1024.0))))
 625             drwxrwxrwx                  ; attribute string
 626             (if (memq 'links ls-lisp-verbosity)
 627                 (format "%3d" (nth 1 file-attr))) ; link count
 628             ;; Numeric uid/gid are more confusing than helpful;
 629             ;; Emacs should be able to make strings of them.
 630             ;; They tend to be bogus on non-UNIX platforms anyway so
 631             ;; optionally hide them.
 632             (if (memq 'uid ls-lisp-verbosity)
 633                 ;; uid can be a string or an integer
 634                 (let ((uid (nth 2 file-attr)))
 635                   (format (if (stringp uid)
 636                               ls-lisp-uid-s-fmt
 637                             ls-lisp-uid-d-fmt)
 638                           uid)))
 639             (if (not (memq ?G switches)) ; GNU ls -- shows group by default
 640                 (if (or (memq ?g switches) ; UNIX ls -- no group by default
 641                         (memq 'gid ls-lisp-verbosity))
 642                     (let ((gid (nth 3 file-attr)))
 643                       (format (if (stringp gid)
 644                                   ls-lisp-gid-s-fmt
 645                                 ls-lisp-gid-d-fmt)
 646                               gid))))
 647             (ls-lisp-format-file-size file-size (memq ?h switches))
 648             " "
 649             (ls-lisp-format-time file-attr time-index now)
 650             " "
 651             (if (not (memq ?F switches)) ; ls-lisp-classify already did that
 652                 (propertize file-name 'dired-filename t)
 653               file-name)
 654             (if (stringp file-type)     ; is a symbolic link
 655                 (concat " -> " file-type))
 656             "\n"
 657             )))
 658
 659 (defun ls-lisp-time-index (switches)
 660   "Return time index into file-attributes according to ls SWITCHES list.
 661 Return nil if no time switch found."
 662   ;; FJW: Default of nil is IMPORTANT and used in `ls-lisp-handle-switches'!
 663   (cond ((memq ?c switches) 6)          ; last mode change
 664         ((memq ?t switches) 5)          ; last modtime
 665         ((memq ?u switches) 4)))        ; last access
 666
 667 (defun ls-lisp-format-time (file-attr time-index now)
 668   "Format time for file with attributes FILE-ATTR according to TIME-INDEX.
 669 Use the same method as ls to decide whether to show time-of-day or year,
 670 depending on distance between file date and NOW.
 671 All ls time options, namely c, t and u, are handled."
 672   (let* ((time (nth (or time-index 5) file-attr)) ; default is last modtime
 673          (diff (- (float-time time)
 674                   (float-time now)))
 675          ;; Consider a time to be recent if it is within the past six
 676          ;; months.  A Gregorian year has 365.2425 * 24 * 60 * 60 ==
 677          ;; 31556952 seconds on the average, and half of that is 15778476.
 678          ;; Write the constant explicitly to avoid roundoff error.
 679          (past-cutoff -15778476)) ; half a Gregorian year
 680     (condition-case nil
 681         ;; Use traditional time format in the C or POSIX locale,
 682         ;; ISO-style time format otherwise, so columns line up.
 683         (let ((locale system-time-locale))
 684           (if (not locale)
 685               (let ((vars '("LC_ALL" "LC_TIME" "LANG")))
 686                 (while (and vars (not (setq locale (getenv (car vars)))))
 687                   (setq vars (cdr vars)))))
 688           (if (member locale '("C" "POSIX"))
 689               (setq locale nil))
 690           (format-time-string
 691            (if (and (<= past-cutoff diff) (<= diff 0))
 692                (if (and locale (not ls-lisp-use-localized-time-format))
 693                    "%m-%d %H:%M"
 694                  (nth 0 ls-lisp-format-time-list))
 695              (if (and locale (not ls-lisp-use-localized-time-format))
 696                  "%Y-%m-%d "
 697                (nth 1 ls-lisp-format-time-list)))
 698            time))
 699       (error "Unk  0  0000"))))
 700
 701 (defun ls-lisp-format-file-size (file-size human-readable)
 702   (if (not human-readable)
 703       (format (if (floatp file-size)
 704                   ls-lisp-filesize-f-fmt
 705                 ls-lisp-filesize-d-fmt)
 706               file-size)
 707     (if (< file-size 1024)
 708         (format " %4d" file-size)
 709       (do ((file-size (/ file-size 1024.0) (/ file-size 1024.0))
 710            ;; kilo, mega, giga, tera, peta, exa
 711            (post-fixes (list "k" "M" "G" "T" "P" "E") (cdr post-fixes)))
 712           ((< file-size 1024)
 713            (format " %3.0f%s"  file-size (car post-fixes)))))))
 714
 715 (provide 'ls-lisp)
 716
 717 ;;; ls-lisp.el ends here