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,
   4 ;;   2005, 2006, 2007, 2008 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
  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 3 of the License, or
  16 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;; OVERVIEW ==========================================================
  29
  30 ;; This file redefines the function `insert-directory' to implement it
  31 ;; directly from Emacs lisp, without running ls in a subprocess.  It
  32 ;; is useful if you cannot afford to fork Emacs on a real memory UNIX,
  33 ;; under VMS or other non-UNIX platforms if you don't have the ls
  34 ;; program, or if you want a different format from what ls offers.
  35
  36 ;; This function can use regexps instead of shell wildcards.  If you
  37 ;; enter regexps remember to double each $ sign.  For example, to
  38 ;; include files *.el, enter `.*\.el$$', resulting in the regexp
  39 ;; `.*\.el$'.
  40
  41 ;; RESTRICTIONS ======================================================
  42
  43 ;; * A few obscure ls switches are still ignored: see the docstring of
  44 ;; `insert-directory'.
  45
  46 ;; TO DO =============================================================
  47
  48 ;; Complete handling of F switch (if/when possible).
  49
  50 ;; FJW: May be able to sort much faster by consing the sort key onto
  51 ;; the front of each list element, sorting and then stripping the key
  52 ;; off again!
  53
  54 ;;; History:
  55
  56 ;; Written originally by Sebastian Kremer <sk@thp.uni-koeln.de>
  57 ;; Revised by Andrew Innes and Geoff Volker (and maybe others).
  58
  59 ;; Modified by Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>, mainly
  60 ;; to support many more ls options, "platform emulation" and more
  61 ;; robust sorting.
  62
  63 ;;; Code:
  64
  65 (eval-when-compile (require 'cl))
  66
  67 (defgroup ls-lisp nil
  68   "Emulate the ls program completely in Emacs Lisp."
  69   :version "21.1"
  70   :group 'dired)
  71
  72 (defcustom ls-lisp-emulation
  73   (cond ((eq system-type 'macos) 'MacOS)
  74         ;; ((eq system-type 'windows-nt) 'MS-Windows)
  75         ((memq system-type
  76                '(hpux usg-unix-v unisoft-unix 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 '(macos 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 c i r S s t u U X g G B C R n and F partly."
 224   (if ls-lisp-use-insert-directory-program
 225       (funcall original-insert-directory
 226                file switches wildcard full-directory-p)
 227     ;; We need the directory in order to find the right handler.
 228     (let ((handler (find-file-name-handler (expand-file-name file)
 229                                            'insert-directory))
 230           (orig-file file)
 231           wildcard-regexp)
 232       (if handler
 233           (funcall handler 'insert-directory file switches
 234                    wildcard full-directory-p)
 235         ;; Remove --dired switch
 236         (if (string-match "--dired " switches)
 237             (setq switches (replace-match "" nil nil switches)))
 238         ;; Convert SWITCHES to a list of characters.
 239         (setq switches (delete ?- (append switches nil)))
 240         ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
 241         ;; `ls' don't mind, we certainly do, because it makes us think
 242         ;; there is no wildcard, only a directory name.
 243         (if (and ls-lisp-support-shell-wildcards
 244                  (string-match "[[?*]" file)
 245                  ;; Prefer an existing file to wildcards, like
 246                  ;; dired-noselect does.
 247                  (not (file-exists-p file)))
 248             (progn
 249               (or (not (eq (aref file (1- (length file))) ?/))
 250                   (setq file (substring file 0 (1- (length file)))))
 251               (setq wildcard t)))
 252         (if wildcard
 253             (setq wildcard-regexp
 254                   (if ls-lisp-support-shell-wildcards
 255                       (wildcard-to-regexp (file-name-nondirectory file))
 256                     (file-name-nondirectory file))
 257                   file (file-name-directory file))
 258           (if (memq ?B switches) (setq wildcard-regexp "[^~]\\'")))
 259         (condition-case err
 260             (ls-lisp-insert-directory
 261              file switches (ls-lisp-time-index switches)
 262              wildcard-regexp full-directory-p)
 263           (invalid-regexp
 264            ;; Maybe they wanted a literal file that just happens to
 265            ;; use characters special to shell wildcards.
 266            (if (equal (cadr err) "Unmatched [ or [^")
 267                (progn
 268                  (setq wildcard-regexp (if (memq ?B switches) "[^~]\\'")
 269                        file (file-relative-name orig-file))
 270                  (ls-lisp-insert-directory
 271                   file switches (ls-lisp-time-index switches)
 272                   nil full-directory-p))
 273              (signal (car err) (cdr err)))))
 274         ;; Try to insert the amount of free space.
 275         (save-excursion
 276           (goto-char (point-min))
 277           ;; First find the line to put it on.
 278           (when (re-search-forward "^total" nil t)
 279             (let ((available (get-free-disk-space ".")))
 280               (when available
 281                 ;; Replace "total" with "total used", to avoid confusion.
 282                 (replace-match "total used in directory")
 283                 (end-of-line)
 284                 (insert " available " available)))))))))
 285
 286 (defun ls-lisp-insert-directory
 287   (file switches time-index wildcard-regexp full-directory-p)
 288   "Insert directory listing for FILE, formatted according to SWITCHES.
 289 Leaves point after the inserted text.  This is an internal function
 290 optionally called by the `ls-lisp.el' version of `insert-directory'.
 291 It is called recursively if the -R switch is used.
 292 SWITCHES is a *list* of characters.  TIME-INDEX is the time index into
 293 file-attributes according to SWITCHES.  WILDCARD-REGEXP is nil or an *Emacs
 294 regexp*.  FULL-DIRECTORY-P means file is a directory and SWITCHES does
 295 not contain `d', so that a full listing is expected."
 296   (if (or wildcard-regexp full-directory-p)
 297       (let* ((dir (file-name-as-directory file))
 298              (default-directory dir)    ; so that file-attributes works
 299              (file-alist
 300               (directory-files-and-attributes dir nil wildcard-regexp t
 301                                               (if (memq ?n switches)
 302                                                   'integer
 303                                                 'string)))
 304              (now (current-time))
 305              (sum 0)
 306              (max-uid-len 0)
 307              (max-gid-len 0)
 308              (max-file-size 0)
 309              ;; do all bindings here for speed
 310              total-line files elt short file-size fil attr
 311              fuid fgid uid-len gid-len)
 312         (cond ((memq ?A switches)
 313                (setq file-alist
 314                      (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
 315               ((not (memq ?a switches))
 316                ;; if neither -A  nor -a, flush . files
 317                (setq file-alist
 318                      (ls-lisp-delete-matching "^\\." file-alist))))
 319         (setq file-alist
 320               (ls-lisp-handle-switches file-alist switches))
 321         (if (memq ?C switches)          ; column (-C) format
 322             (ls-lisp-column-format file-alist)
 323           (setq total-line (cons (point) (car-safe file-alist)))
 324           ;; Find the appropriate format for displaying uid, gid, and
 325           ;; file size, by finding the longest strings among all the
 326           ;; files we are about to display.
 327           (dolist (elt file-alist)
 328             (setq attr (cdr elt)
 329                   fuid (nth 2 attr)
 330                   uid-len (if (stringp fuid) (string-width fuid)
 331                             (length (format "%d" fuid)))
 332                   fgid (nth 3 attr)
 333                   gid-len (if (stringp fgid) (string-width fgid)
 334                             (length (format "%d" fgid)))
 335                   file-size (nth 7 attr))
 336             (if (> uid-len max-uid-len)
 337                 (setq max-uid-len uid-len))
 338             (if (> gid-len max-gid-len)
 339                 (setq max-gid-len gid-len))
 340             (if (> file-size max-file-size)
 341                 (setq max-file-size file-size)))
 342           (setq ls-lisp-uid-d-fmt (format " %%-%dd" max-uid-len))
 343           (setq ls-lisp-uid-s-fmt (format " %%-%ds" max-uid-len))
 344           (setq ls-lisp-gid-d-fmt (format " %%-%dd" max-gid-len))
 345           (setq ls-lisp-gid-s-fmt (format " %%-%ds" max-gid-len))
 346           (setq ls-lisp-filesize-d-fmt
 347                 (format " %%%dd"
 348                         (if (memq ?s switches)
 349                             (length (format "%.0f"
 350                                             (fceiling (/ max-file-size 1024.0))))
 351                           (length (format "%.0f" max-file-size)))))
 352           (setq ls-lisp-filesize-f-fmt
 353                 (format " %%%d.0f"
 354                         (if (memq ?s switches)
 355                             (length (format "%.0f"
 356                                             (fceiling (/ max-file-size 1024.0))))
 357                           (length (format "%.0f" max-file-size)))))
 358           (setq files file-alist)
 359           (while files                  ; long (-l) format
 360             (setq elt (car files)
 361                   files (cdr files)
 362                   short (car elt)
 363                   attr (cdr elt)
 364                   file-size (nth 7 attr))
 365             (and attr
 366                  (setq sum (+ file-size
 367                               ;; Even if neither SUM nor file's size
 368                               ;; overflow, their sum could.
 369                               (if (or (< sum (- 134217727 file-size))
 370                                       (floatp sum)
 371                                       (floatp file-size))
 372                                   sum
 373                                 (float sum))))
 374                  (insert (ls-lisp-format short attr file-size
 375                                          switches time-index now))))
 376           ;; Insert total size of all files:
 377           (save-excursion
 378             (goto-char (car total-line))
 379             (or (cdr total-line)
 380                 ;; Shell says ``No match'' if no files match
 381                 ;; the wildcard; let's say something similar.
 382                 (insert "(No match)\n"))
 383             (insert (format "total %.0f\n" (fceiling (/ sum 1024.0))))))
 384         (if (memq ?R switches)
 385             ;; List the contents of all directories recursively.
 386             ;; cadr of each element of `file-alist' is t for
 387             ;; directory, string (name linked to) for symbolic
 388             ;; link, or nil.
 389             (while file-alist
 390               (setq elt (car file-alist)
 391                     file-alist (cdr file-alist))
 392               (when (and (eq (cadr elt) t) ; directory
 393                          (not (string-match "\\`\\.\\.?\\'" (car elt))))
 394                 (setq elt (expand-file-name (car elt) dir))
 395                 (insert "\n" elt ":\n")
 396                 (ls-lisp-insert-directory
 397                  elt switches time-index wildcard-regexp full-directory-p)))))
 398     ;; If not full-directory-p, FILE *must not* end in /, as
 399     ;; file-attributes will not recognize a symlink to a directory,
 400     ;; so must make it a relative filename as ls does:
 401     (if (eq (aref file (1- (length file))) ?/)
 402         (setq file (substring file 0 -1)))
 403     (let ((fattr (file-attributes file 'string)))
 404       (if fattr
 405           (insert (ls-lisp-format file fattr (nth 7 fattr)
 406                                   switches time-index (current-time)))
 407         (message "%s: doesn't exist or is inaccessible" file)
 408         (ding) (sit-for 2)))))          ; to show user the message!
 409
 410 (defun ls-lisp-column-format (file-alist)
 411   "Insert the file names (only) in FILE-ALIST into the current buffer.
 412 Format in columns, sorted vertically, following GNU ls -C.
 413 Responds to the window width as ls should but may not!"
 414   (let (files fmt ncols collen (nfiles 0) (colwid 0))
 415     ;; Count number of files as `nfiles', build list of filenames as
 416     ;; `files', and find maximum filename length as `colwid':
 417     (let (file len)
 418       (while file-alist
 419         (setq nfiles (1+ nfiles)
 420               file (caar file-alist)
 421               files (cons file files)
 422               file-alist (cdr file-alist)
 423               len (length file))
 424         (if (> len colwid) (setq colwid len))))
 425     (setq files (nreverse files)
 426           colwid (+ 2 colwid)           ; 2 character column gap
 427           fmt (format "%%-%ds" colwid)  ; print format
 428           ncols (/ (window-width) colwid) ; no of columns
 429           collen (/ nfiles ncols))      ; floor of column length
 430     (if (> nfiles (* collen ncols)) (setq collen (1+ collen)))
 431     ;; Output the file names in columns, sorted vertically:
 432     (let ((i 0) j)
 433       (while (< i collen)
 434         (setq j i)
 435         (while (< j nfiles)
 436           (insert (format fmt (nth j files)))
 437           (setq j (+ j collen)))
 438         ;; FJW: This is completely unnecessary, but I don't like
 439         ;; trailing white space...
 440         (delete-region (point) (progn (skip-chars-backward " \t") (point)))
 441         (insert ?\n)
 442         (setq i (1+ i))))))
 443
 444 (defun ls-lisp-delete-matching (regexp list)
 445   "Delete all elements matching REGEXP from LIST, return new list."
 446   ;; Should perhaps use setcdr for efficiency.
 447   (let (result)
 448     (while list
 449       (or (string-match regexp (caar list))
 450           (setq result (cons (car list) result)))
 451       (setq list (cdr list)))
 452     result))
 453
 454 (defsubst ls-lisp-string-lessp (s1 s2)
 455   "Return t if string S1 is less than string S2 in lexicographic order.
 456 Case is significant if `ls-lisp-ignore-case' is nil.
 457 Unibyte strings are converted to multibyte for comparison."
 458   (let ((u (compare-strings s1 0 nil s2 0 nil ls-lisp-ignore-case)))
 459     (and (numberp u) (< u 0))))
 460
 461 (defun ls-lisp-handle-switches (file-alist switches)
 462   "Return new FILE-ALIST sorted according to SWITCHES.
 463 SWITCHES is a list of characters.  Default sorting is alphabetic."
 464   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
 465   (or (memq ?U switches)                ; unsorted
 466       ;; Catch and ignore unexpected sorting errors
 467       (condition-case err
 468           (setq file-alist
 469                 (let (index)
 470                   ;; Copy file-alist in case of error
 471                   (sort (copy-sequence file-alist) ; modifies its argument!
 472                         (cond ((memq ?S switches)
 473                                (lambda (x y) ; sorted on size
 474                                  ;; 7th file attribute is file size
 475                                  ;; Make largest file come first
 476                                  (< (nth 7 (cdr y))
 477                                     (nth 7 (cdr x)))))
 478                               ((setq index (ls-lisp-time-index switches))
 479                                (lambda (x y) ; sorted on time
 480                                  (ls-lisp-time-lessp (nth index (cdr y))
 481                                                      (nth index (cdr x)))))
 482                               ((memq ?X switches)
 483                                (lambda (x y) ; sorted on extension
 484                                  (ls-lisp-string-lessp
 485                                   (ls-lisp-extension (car x))
 486                                   (ls-lisp-extension (car y)))))
 487                               (t
 488                                (lambda (x y) ; sorted alphabetically
 489                                  (ls-lisp-string-lessp (car x) (car y))))))))
 490         (error (message "Unsorted (ls-lisp sorting error) - %s"
 491                         (error-message-string err))
 492                (ding) (sit-for 2))))    ; to show user the message!
 493   (if (memq ?F switches)                ; classify switch
 494       (setq file-alist (mapcar 'ls-lisp-classify file-alist)))
 495   (if ls-lisp-dirs-first
 496   ;; Re-sort directories first, without otherwise changing the
 497   ;; ordering, and reverse whole list.  cadr of each element of
 498   ;; `file-alist' is t for directory, string (name linked to) for
 499   ;; symbolic link, or nil.
 500       (let (el dirs files)
 501         (while file-alist
 502           (if (or (eq (cadr (setq el (car file-alist))) t) ; directory
 503                   (and (stringp (cadr el))
 504                        (file-directory-p (cadr el)))) ; symlink to a directory
 505               (setq dirs (cons el dirs))
 506             (setq files (cons el files)))
 507           (setq file-alist (cdr file-alist)))
 508         (setq file-alist
 509               (if (memq ?U switches)    ; unsorted order is reversed
 510                   (nconc dirs files)
 511                 (nconc files dirs)
 512                 ))))
 513   ;; Finally reverse file alist if necessary.
 514   ;; (eq below MUST compare `(not (memq ...))' to force comparison of
 515   ;; `t' or `nil', rather than list tails!)
 516   (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
 517               (not (memq ?r switches))) ; reversed sort order requested
 518           ls-lisp-dirs-first)           ; already reversed
 519       (nreverse file-alist)
 520     file-alist))
 521
 522 (defun ls-lisp-classify (filedata)
 523   "Append a character to each file name indicating the file type.
 524 Also, for regular files that are executable, append `*'.
 525 The file type indicators are `/' for directories, `@' for symbolic
 526 links, `|' for FIFOs, `=' for sockets, and nothing for regular files.
 527 \[But FIFOs and sockets are not recognized.]
 528 FILEDATA has the form (filename . `file-attributes').  Its `cadr' is t
 529 for directory, string (name linked to) for symbolic link, or nil."
 530   (let ((file-name (car filedata))
 531         (type (cadr filedata)))
 532     (cond (type
 533            (cons
 534             (concat file-name (if (eq type t) "/" "@"))
 535             (cdr filedata)))
 536           ((string-match "x" (nth 9 filedata))
 537            (cons
 538             (concat file-name "*")
 539             (cdr filedata)))
 540           (t filedata))))
 541
 542 (defun ls-lisp-extension (filename)
 543   "Return extension of FILENAME (ignoring any version extension)
 544 FOLLOWED by null and full filename, SOLELY for full alpha sort."
 545   ;; Force extension sort order: `no ext' then `null ext' then `ext'
 546   ;; to agree with GNU ls.
 547   (concat
 548    (let* ((i (length filename)) end)
 549      (if (= (aref filename (1- i)) ?.) ; null extension
 550          "\0"
 551        (while (and (>= (setq i (1- i)) 0)
 552                    (/= (aref filename i) ?.)))
 553        (if (< i 0) "\0\0"               ; no extension
 554          (if (/= (aref filename (1+ i)) ?~)
 555              (substring filename (1+ i))
 556            ;; version extension found -- ignore it
 557            (setq end i)
 558            (while (and (>= (setq i (1- i)) 0)
 559                        (/= (aref filename i) ?.)))
 560            (if (< i 0) "\0\0"   ; no extension
 561              (substring filename (1+ i) end))))
 562        )) "\0" filename))
 563
 564 ;; From Roland McGrath.  Can use this to sort on time.
 565 (defun ls-lisp-time-lessp (time0 time1)
 566   "Return t if time TIME0 is earlier than time TIME1."
 567   (let ((hi0 (car time0)) (hi1 (car time1)))
 568     (or (< hi0 hi1)
 569         (and (= hi0 hi1)
 570              (< (cadr time0) (cadr time1))))))
 571
 572 (defun ls-lisp-format (file-name file-attr file-size switches time-index now)
 573   "Format one line of long ls output for file FILE-NAME.
 574 FILE-ATTR and FILE-SIZE give the file's attributes and size.
 575 SWITCHES, TIME-INDEX and NOW give the full switch list and time data."
 576   (let ((file-type (nth 0 file-attr))
 577         ;; t for directory, string (name linked to)
 578         ;; for symbolic link, or nil.
 579         (drwxrwxrwx (nth 8 file-attr))) ; attribute string ("drwxrwxrwx")
 580     (concat (if (memq ?i switches)      ; inode number
 581                 (let ((inode (nth 10 file-attr)))
 582                   (if (consp inode)
 583                       (if (consp (cdr inode))
 584                           ;; 2^(24+16) = 1099511627776.0, but
 585                           ;; multiplying by it and then adding the
 586                           ;; other members of the cons cell in one go
 587                           ;; loses precision, since a double does not
 588                           ;; have enough significant digits to hold a
 589                           ;; full 64-bit value.  So below we split
 590                           ;; 1099511627776 into high 13 and low 5
 591                           ;; digits and compute in two parts.
 592                           (let ((p1 (* (car inode) 10995116.0))
 593                                 (p2 (+ (* (car inode) 27776.0)
 594                                        (* (cadr inode) 65536.0)
 595                                        (cddr inode))))
 596                             (format " %13.0f%05.0f "
 597                                     ;; Use floor to emulate integer
 598                                     ;; division.
 599                                     (+ p1 (floor p2 100000.0))
 600                                     (mod p2 100000.0)))
 601                         (format " %18.0f "
 602                                 (+ (* (car inode) 65536.0)
 603                                    (cdr inode))))
 604                     (format " %18d " inode))))
 605             ;; nil is treated like "" in concat
 606             (if (memq ?s switches)      ; size in K
 607                 (format ls-lisp-filesize-f-fmt
 608                         (fceiling (/ file-size 1024.0))))
 609             drwxrwxrwx                  ; attribute string
 610             (if (memq 'links ls-lisp-verbosity)
 611                 (format "%3d" (nth 1 file-attr))) ; link count
 612             ;; Numeric uid/gid are more confusing than helpful;
 613             ;; Emacs should be able to make strings of them.
 614             ;; They tend to be bogus on non-UNIX platforms anyway so
 615             ;; optionally hide them.
 616             (if (memq 'uid ls-lisp-verbosity)
 617                 ;; uid can be a sting or an integer
 618                 (let ((uid (nth 2 file-attr)))
 619                   (format (if (stringp uid)
 620                               ls-lisp-uid-s-fmt
 621                             ls-lisp-uid-d-fmt)
 622                           uid)))
 623             (if (not (memq ?G switches)) ; GNU ls -- shows group by default
 624                 (if (or (memq ?g switches) ; UNIX ls -- no group by default
 625                         (memq 'gid ls-lisp-verbosity))
 626                     (let ((gid (nth 3 file-attr)))
 627                       (format (if (stringp gid)
 628                                   ls-lisp-gid-s-fmt
 629                                 ls-lisp-gid-d-fmt)
 630                               gid))))
 631             (ls-lisp-format-file-size file-size (memq ?h switches))
 632             " "
 633             (ls-lisp-format-time file-attr time-index now)
 634             " "
 635             (propertize file-name 'dired-filename t)
 636             (if (stringp file-type)     ; is a symbolic link
 637                 (concat " -> " file-type))
 638             "\n"
 639             )))
 640
 641 (defun ls-lisp-time-index (switches)
 642   "Return time index into file-attributes according to ls SWITCHES list.
 643 Return nil if no time switch found."
 644   ;; FJW: Default of nil is IMPORTANT and used in `ls-lisp-handle-switches'!
 645   (cond ((memq ?c switches) 6)          ; last mode change
 646         ((memq ?t switches) 5)          ; last modtime
 647         ((memq ?u switches) 4)))        ; last access
 648
 649 (defun ls-lisp-time-to-seconds (time)
 650   "Convert TIME to a floating point number."
 651   (+ (* (car time) 65536.0)
 652      (cadr time)
 653      (/ (or (nth 2 time) 0) 1000000.0)))
 654
 655 (defun ls-lisp-format-time (file-attr time-index now)
 656   "Format time for file with attributes FILE-ATTR according to TIME-INDEX.
 657 Use the same method as ls to decide whether to show time-of-day or year,
 658 depending on distance between file date and NOW.
 659 All ls time options, namely c, t and u, are handled."
 660   (let* ((time (nth (or time-index 5) file-attr)) ; default is last modtime
 661          (diff (- (ls-lisp-time-to-seconds time)
 662                   (ls-lisp-time-to-seconds now)))
 663          ;; Consider a time to be recent if it is within the past six
 664          ;; months.  A Gregorian year has 365.2425 * 24 * 60 * 60 ==
 665          ;; 31556952 seconds on the average, and half of that is 15778476.
 666          ;; Write the constant explicitly to avoid roundoff error.
 667          (past-cutoff -15778476)) ; half a Gregorian year
 668     (condition-case nil
 669         ;; Use traditional time format in the C or POSIX locale,
 670         ;; ISO-style time format otherwise, so columns line up.
 671         (let ((locale system-time-locale))
 672           (if (not locale)
 673               (let ((vars '("LC_ALL" "LC_TIME" "LANG")))
 674                 (while (and vars (not (setq locale (getenv (car vars)))))
 675                   (setq vars (cdr vars)))))
 676           (if (member locale '("C" "POSIX"))
 677               (setq locale nil))
 678           (format-time-string
 679            (if (and (<= past-cutoff diff) (<= diff 0))
 680                (if (and locale (not ls-lisp-use-localized-time-format))
 681                    "%m-%d %H:%M"
 682                  (nth 0 ls-lisp-format-time-list))
 683              (if (and locale (not ls-lisp-use-localized-time-format))
 684                  "%Y-%m-%d "
 685                (nth 1 ls-lisp-format-time-list)))
 686            time))
 687       (error "Unk  0  0000"))))
 688
 689 (defun ls-lisp-format-file-size (file-size human-readable)
 690   (if (not human-readable)
 691       (format (if (floatp file-size)
 692                   ls-lisp-filesize-f-fmt
 693                 ls-lisp-filesize-d-fmt)
 694               file-size)
 695     (if (< file-size 1024)
 696         (format " %4d" file-size)
 697       (do ((file-size (/ file-size 1024.0) (/ file-size 1024.0))
 698            ;; kilo, mega, giga, tera, peta, exa
 699            (post-fixes (list "k" "M" "G" "T" "P" "E") (cdr post-fixes)))
 700           ((< file-size 1024)
 701            (format " %3.0f%s"  file-size (car post-fixes)))))))
 702
 703 (provide 'ls-lisp)
 704
 705 ;; arch-tag: e55f399b-05ec-425c-a6d5-f5e349c35ab4
 706 ;;; ls-lisp.el ends here