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, 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
  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 ;; 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 'windows-nt) 'MS-Windows)
  74         ((memq system-type
  75                '(hpux usg-unix-v irix berkeley-unix))
  76          'UNIX))                        ; very similar to GNU
  77   ;; Anything else defaults to nil, meaning GNU.
  78   "Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
  79 Corresponding value is one of the atoms: nil, MacOS, MS-Windows, UNIX.
  80 Sets default values for: `ls-lisp-ignore-case', `ls-lisp-dirs-first',
  81 `ls-lisp-verbosity'.  Need not match actual platform.  Changing this
  82 option will have no effect until you restart Emacs."
  83   :type '(choice (const :tag "GNU" nil)
  84                  (const MacOS)
  85                  (const MS-Windows)
  86                  (const UNIX))
  87   :group 'ls-lisp)
  88
  89 ;; Only made an obsolete alias in 23.3.  Before that, the initial
  90 ;; value was set according to:
  91 ;;  (or (memq ls-lisp-emulation '(MS-Windows MacOS))
  92 ;;      (and (boundp 'ls-lisp-dired-ignore-case) ls-lisp-dired-ignore-case))
  93 ;; Which isn't the right thing to do.
  94 (define-obsolete-variable-alias 'ls-lisp-dired-ignore-case
  95   'ls-lisp-ignore-case "21.1")
  96
  97 (defcustom ls-lisp-ignore-case
  98   (memq ls-lisp-emulation '(MS-Windows MacOS))
  99   "Non-nil causes ls-lisp alphabetic sorting to ignore case."
 100   :type 'boolean
 101   :group 'ls-lisp)
 102
 103 (defcustom ls-lisp-dirs-first (eq ls-lisp-emulation 'MS-Windows)
 104   "Non-nil causes ls-lisp to sort directories first in any ordering.
 105 \(Or last if it is reversed.)  Follows Microsoft Windows Explorer."
 106   ;; Functionality suggested by Chris McMahan <cmcmahan@one.net>
 107   :type 'boolean
 108   :group 'ls-lisp)
 109
 110 (defcustom ls-lisp-verbosity
 111   (cond ((eq ls-lisp-emulation 'MacOS) nil)
 112         ((eq ls-lisp-emulation 'MS-Windows)
 113          (if (and (fboundp 'w32-using-nt) (w32-using-nt))
 114              '(links)))                 ; distinguish NT/2K from 9x
 115         ((eq ls-lisp-emulation 'UNIX) '(links uid)) ; UNIX ls
 116         (t '(links uid gid)))           ; GNU ls
 117   "A list of optional file attributes that ls-lisp should display.
 118 It should contain none or more of the symbols: links, uid, gid.
 119 A value of nil (or an empty list) means display none of them.
 120
 121 Concepts come from UNIX: `links' means count of names associated with
 122 the file\; `uid' means user (owner) identifier\; `gid' means group
 123 identifier.
 124
 125 If emulation is MacOS then default is nil\;
 126 if emulation is MS-Windows then default is `(links)' if platform is
 127 Windows NT/2K, nil otherwise\;
 128 if emulation is UNIX then default is `(links uid)'\;
 129 if emulation is GNU then default is `(links uid gid)'."
 130   ;; Functionality suggested by Howard Melman <howard@silverstream.com>
 131   :type '(set (const :tag "Show Link Count" links)
 132               (const :tag "Show User" uid)
 133               (const :tag "Show Group" gid))
 134   :group 'ls-lisp)
 135
 136 (defcustom ls-lisp-use-insert-directory-program
 137   (not (memq system-type '(ms-dos windows-nt)))
 138   "Non-nil causes ls-lisp to revert back to using `insert-directory-program'.
 139 This is useful on platforms where ls-lisp is dumped into Emacs, such as
 140 Microsoft Windows, but you would still like to use a program to list
 141 the contents of a directory."
 142   :type 'boolean
 143   :group 'ls-lisp)
 144
 145 ;;; Autoloaded because it is let-bound in `recover-session', `mail-recover-1'.
 146 ;;;###autoload
 147 (defcustom ls-lisp-support-shell-wildcards t
 148   "Non-nil means ls-lisp treats file patterns as shell wildcards.
 149 Otherwise they are treated as Emacs regexps (for backward compatibility)."
 150   :type 'boolean
 151   :group 'ls-lisp)
 152
 153 (defcustom ls-lisp-format-time-list
 154   '("%b %e %H:%M"
 155     "%b %e  %Y")
 156   "List of `format-time-string' specs to display file time stamps.
 157 These specs are used ONLY if a valid locale can not be determined.
 158
 159 If `ls-lisp-use-localized-time-format' is non-nil, these specs are used
 160 regardless of whether the locale can be determined.
 161
 162 Syntax:  (EARLY-TIME-FORMAT OLD-TIME-FORMAT)
 163
 164 The EARLY-TIME-FORMAT is used if file has been modified within the
 165 current year. The OLD-TIME-FORMAT is used for older files.  To use ISO
 166 8601 dates, you could set:
 167
 168 \(setq ls-lisp-format-time-list
 169        '(\"%Y-%m-%d %H:%M\"
 170          \"%Y-%m-%d      \"))"
 171   :type '(list (string :tag "Early time format")
 172                (string :tag "Old time format"))
 173   :group 'ls-lisp)
 174
 175 (defcustom ls-lisp-use-localized-time-format nil
 176   "Non-nil causes ls-lisp to use `ls-lisp-format-time-list' even if
 177 a valid locale is specified.
 178
 179 WARNING: Using localized date/time format might cause Dired columns
 180 to fail to lign up, e.g. if month names are not all of the same length."
 181   :type 'boolean
 182   :group 'ls-lisp)
 183
 184 (defvar original-insert-directory nil
 185   "This holds the original function definition of `insert-directory'.")
 186
 187 (defvar ls-lisp-uid-d-fmt "-%d"
 188   "Format to display integer UIDs.")
 189 (defvar ls-lisp-uid-s-fmt "-%s"
 190   "Format to display user names.")
 191 (defvar ls-lisp-gid-d-fmt "-%d"
 192   "Format to display integer GIDs.")
 193 (defvar ls-lisp-gid-s-fmt "-%s"
 194   "Format to display user group names.")
 195 (defvar ls-lisp-filesize-d-fmt "%d"
 196   "Format to display integer file sizes.")
 197 (defvar ls-lisp-filesize-f-fmt "%.0f"
 198   "Format to display float file sizes.")
 199
 200 ;; Remember the original insert-directory function
 201 (or (featurep 'ls-lisp)  ; FJW: unless this file is being reloaded!
 202     (setq original-insert-directory (symbol-function 'insert-directory)))
 203
 204 \f
 205 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 206
 207 (defun insert-directory (file switches &optional wildcard full-directory-p)
 208   "Insert directory listing for FILE, formatted according to SWITCHES.
 209 Leaves point after the inserted text.
 210 SWITCHES may be a string of options, or a list of strings.
 211 Optional third arg WILDCARD means treat FILE as shell wildcard.
 212 Optional fourth arg FULL-DIRECTORY-P means file is a directory and
 213 switches do not contain `d', so that a full listing is expected.
 214
 215 This version of the function comes from `ls-lisp.el'.
 216 If the value of `ls-lisp-use-insert-directory-program' is non-nil then
 217 it works exactly like the version from `files.el' and runs a directory
 218 listing program whose name is in the variable
 219 `insert-directory-program'; if also WILDCARD is non-nil then it runs
 220 the shell specified by `shell-file-name'.  If the value of
 221 `ls-lisp-use-insert-directory-program' is nil then it runs a Lisp
 222 emulation.
 223
 224 The Lisp emulation does not run any external programs or shells.  It
 225 supports ordinary shell wildcards if `ls-lisp-support-shell-wildcards'
 226 is non-nil; otherwise, it interprets wildcards as regular expressions
 227 to match file names.  It does not support all `ls' switches -- those
 228 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
 229 is assumed to be always present and cannot be turned off."
 230   (if ls-lisp-use-insert-directory-program
 231       (funcall original-insert-directory
 232                file switches wildcard full-directory-p)
 233     ;; We need the directory in order to find the right handler.
 234     (let ((handler (find-file-name-handler (expand-file-name file)
 235                                            'insert-directory))
 236           (orig-file file)
 237           wildcard-regexp)
 238       (if handler
 239           (funcall handler 'insert-directory file switches
 240                    wildcard full-directory-p)
 241         ;; Remove --dired switch
 242         (if (string-match "--dired " switches)
 243             (setq switches (replace-match "" nil nil switches)))
 244         ;; Convert SWITCHES to a list of characters.
 245         (setq switches (delete ?\  (delete ?- (append switches nil))))
 246         ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
 247         ;; `ls' don't mind, we certainly do, because it makes us think
 248         ;; there is no wildcard, only a directory name.
 249         (if (and ls-lisp-support-shell-wildcards
 250                  (string-match "[[?*]" file)
 251                  ;; Prefer an existing file to wildcards, like
 252                  ;; dired-noselect does.
 253                  (not (file-exists-p file)))
 254             (progn
 255               (or (not (eq (aref file (1- (length file))) ?/))
 256                   (setq file (substring file 0 (1- (length file)))))
 257               (setq wildcard t)))
 258         (if wildcard
 259             (setq wildcard-regexp
 260                   (if ls-lisp-support-shell-wildcards
 261                       (wildcard-to-regexp (file-name-nondirectory file))
 262                     (file-name-nondirectory file))
 263                   file (file-name-directory file))
 264           (if (memq ?B switches) (setq wildcard-regexp "[^~]\\'")))
 265         (condition-case err
 266             (ls-lisp-insert-directory
 267              file switches (ls-lisp-time-index switches)
 268              wildcard-regexp full-directory-p)
 269           (invalid-regexp
 270            ;; Maybe they wanted a literal file that just happens to
 271            ;; use characters special to shell wildcards.
 272            (if (equal (cadr err) "Unmatched [ or [^")
 273                (progn
 274                  (setq wildcard-regexp (if (memq ?B switches) "[^~]\\'")
 275                        file (file-relative-name orig-file))
 276                  (ls-lisp-insert-directory
 277                   file switches (ls-lisp-time-index switches)
 278                   nil full-directory-p))
 279              (signal (car err) (cdr err)))))
 280         ;; Try to insert the amount of free space.
 281         (save-excursion
 282           (goto-char (point-min))
 283           ;; First find the line to put it on.
 284           (when (re-search-forward "^total" nil t)
 285             (let ((available (get-free-disk-space ".")))
 286               (when available
 287                 ;; Replace "total" with "total used", to avoid confusion.
 288                 (replace-match "total used in directory")
 289                 (end-of-line)
 290                 (insert " available " available)))))))))
 291
 292 (defun ls-lisp-insert-directory
 293   (file switches time-index wildcard-regexp full-directory-p)
 294   "Insert directory listing for FILE, formatted according to SWITCHES.
 295 Leaves point after the inserted text.  This is an internal function
 296 optionally called by the `ls-lisp.el' version of `insert-directory'.
 297 It is called recursively if the -R switch is used.
 298 SWITCHES is a *list* of characters.  TIME-INDEX is the time index into
 299 file-attributes according to SWITCHES.  WILDCARD-REGEXP is nil or an *Emacs
 300 regexp*.  FULL-DIRECTORY-P means file is a directory and SWITCHES does
 301 not contain `d', so that a full listing is expected."
 302   (if (or wildcard-regexp full-directory-p)
 303       (let* ((dir (file-name-as-directory file))
 304              (default-directory dir)    ; so that file-attributes works
 305              (file-alist
 306               (directory-files-and-attributes dir nil wildcard-regexp t
 307                                               (if (memq ?n switches)
 308                                                   'integer
 309                                                 'string)))
 310              (now (current-time))
 311              (sum 0)
 312              (max-uid-len 0)
 313              (max-gid-len 0)
 314              (max-file-size 0)
 315              ;; do all bindings here for speed
 316              total-line files elt short file-size fil attr
 317              fuid fgid uid-len gid-len)
 318         (cond ((memq ?A switches)
 319                (setq file-alist
 320                      (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
 321               ((not (memq ?a switches))
 322                ;; if neither -A  nor -a, flush . files
 323                (setq file-alist
 324                      (ls-lisp-delete-matching "^\\." file-alist))))
 325         (setq file-alist
 326               (ls-lisp-handle-switches file-alist switches))
 327         (if (memq ?C switches)          ; column (-C) format
 328             (ls-lisp-column-format file-alist)
 329           (setq total-line (cons (point) (car-safe file-alist)))
 330           ;; Find the appropriate format for displaying uid, gid, and
 331           ;; file size, by finding the longest strings among all the
 332           ;; files we are about to display.
 333           (dolist (elt file-alist)
 334             (setq attr (cdr elt)
 335                   fuid (nth 2 attr)
 336                   uid-len (if (stringp fuid) (string-width fuid)
 337                             (length (format "%d" fuid)))
 338                   fgid (nth 3 attr)
 339                   gid-len (if (stringp fgid) (string-width fgid)
 340                             (length (format "%d" fgid)))
 341                   file-size (nth 7 attr))
 342             (if (> uid-len max-uid-len)
 343                 (setq max-uid-len uid-len))
 344             (if (> gid-len max-gid-len)
 345                 (setq max-gid-len gid-len))
 346             (if (> file-size max-file-size)
 347                 (setq max-file-size file-size)))
 348           (setq ls-lisp-uid-d-fmt (format " %%-%dd" max-uid-len))
 349           (setq ls-lisp-uid-s-fmt (format " %%-%ds" max-uid-len))
 350           (setq ls-lisp-gid-d-fmt (format " %%-%dd" max-gid-len))
 351           (setq ls-lisp-gid-s-fmt (format " %%-%ds" max-gid-len))
 352           (setq ls-lisp-filesize-d-fmt
 353                 (format " %%%dd"
 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 ls-lisp-filesize-f-fmt
 359                 (format " %%%d.0f"
 360                         (if (memq ?s switches)
 361                             (length (format "%.0f"
 362                                             (fceiling (/ max-file-size 1024.0))))
 363                           (length (format "%.0f" max-file-size)))))
 364           (setq files file-alist)
 365           (while files                  ; long (-l) format
 366             (setq elt (car files)
 367                   files (cdr files)
 368                   short (car elt)
 369                   attr (cdr elt)
 370                   file-size (nth 7 attr))
 371             (and attr
 372                  (setq sum (+ file-size
 373                               ;; Even if neither SUM nor file's size
 374                               ;; overflow, their sum could.
 375                               (if (or (< sum (- 134217727 file-size))
 376                                       (floatp sum)
 377                                       (floatp file-size))
 378                                   sum
 379                                 (float sum))))
 380                  (insert (ls-lisp-format short attr file-size
 381                                          switches time-index now))))
 382           ;; Insert total size of all files:
 383           (save-excursion
 384             (goto-char (car total-line))
 385             (or (cdr total-line)
 386                 ;; Shell says ``No match'' if no files match
 387                 ;; the wildcard; let's say something similar.
 388                 (insert "(No match)\n"))
 389             (insert (format "total %.0f\n" (fceiling (/ sum 1024.0))))))
 390         (if (memq ?R switches)
 391             ;; List the contents of all directories recursively.
 392             ;; cadr of each element of `file-alist' is t for
 393             ;; directory, string (name linked to) for symbolic
 394             ;; link, or nil.
 395             (while file-alist
 396               (setq elt (car file-alist)
 397                     file-alist (cdr file-alist))
 398               (when (and (eq (cadr elt) t) ; directory
 399                          ;; Under -F, we have already decorated all
 400                          ;; directories, including "." and "..", with
 401                          ;; a /, so allow for that as well.
 402                          (not (string-match "\\`\\.\\.?/?\\'" (car elt))))
 403                 (setq elt (expand-file-name (car elt) dir))
 404                 (insert "\n" elt ":\n")
 405                 (ls-lisp-insert-directory
 406                  elt switches time-index wildcard-regexp full-directory-p)))))
 407     ;; If not full-directory-p, FILE *must not* end in /, as
 408     ;; file-attributes will not recognize a symlink to a directory,
 409     ;; so must make it a relative filename as ls does:
 410     (if (file-name-absolute-p file) (setq file (expand-file-name file)))
 411     (if (eq (aref file (1- (length file))) ?/)
 412         (setq file (substring file 0 -1)))
 413     (let ((fattr (file-attributes file 'string)))
 414       (if fattr
 415           (insert (ls-lisp-format
 416                    (if (memq ?F switches)
 417                        (ls-lisp-classify-file file fattr)
 418                      file)
 419                    fattr (nth 7 fattr)
 420                                   switches time-index (current-time)))
 421         (message "%s: doesn't exist or is inaccessible" file)
 422         (ding) (sit-for 2)))))          ; to show user the message!
 423
 424 (defun ls-lisp-column-format (file-alist)
 425   "Insert the file names (only) in FILE-ALIST into the current buffer.
 426 Format in columns, sorted vertically, following GNU ls -C.
 427 Responds to the window width as ls should but may not!"
 428   (let (files fmt ncols collen (nfiles 0) (colwid 0))
 429     ;; Count number of files as `nfiles', build list of filenames as
 430     ;; `files', and find maximum filename length as `colwid':
 431     (let (file len)
 432       (while file-alist
 433         (setq nfiles (1+ nfiles)
 434               file (caar file-alist)
 435               files (cons file files)
 436               file-alist (cdr file-alist)
 437               len (length file))
 438         (if (> len colwid) (setq colwid len))))
 439     (setq files (nreverse files)
 440           colwid (+ 2 colwid)           ; 2 character column gap
 441           fmt (format "%%-%ds" colwid)  ; print format
 442           ncols (/ (window-width) colwid) ; no of columns
 443           collen (/ nfiles ncols))      ; floor of column length
 444     (if (> nfiles (* collen ncols)) (setq collen (1+ collen)))
 445     ;; Output the file names in columns, sorted vertically:
 446     (let ((i 0) j)
 447       (while (< i collen)
 448         (setq j i)
 449         (while (< j nfiles)
 450           (insert (format fmt (nth j files)))
 451           (setq j (+ j collen)))
 452         ;; FJW: This is completely unnecessary, but I don't like
 453         ;; trailing white space...
 454         (delete-region (point) (progn (skip-chars-backward " \t") (point)))
 455         (insert ?\n)
 456         (setq i (1+ i))))))
 457
 458 (defun ls-lisp-delete-matching (regexp list)
 459   "Delete all elements matching REGEXP from LIST, return new list."
 460   ;; Should perhaps use setcdr for efficiency.
 461   (let (result)
 462     (while list
 463       (or (string-match regexp (caar list))
 464           (setq result (cons (car list) result)))
 465       (setq list (cdr list)))
 466     result))
 467
 468 (defsubst ls-lisp-string-lessp (s1 s2)
 469   "Return t if string S1 is less than string S2 in lexicographic order.
 470 Case is significant if `ls-lisp-ignore-case' is nil.
 471 Unibyte strings are converted to multibyte for comparison."
 472   (let ((u (compare-strings s1 0 nil s2 0 nil ls-lisp-ignore-case)))
 473     (and (numberp u) (< u 0))))
 474
 475 (defun ls-lisp-handle-switches (file-alist switches)
 476   "Return new FILE-ALIST sorted according to SWITCHES.
 477 SWITCHES is a list of characters.  Default sorting is alphabetic."
 478   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
 479   (or (memq ?U switches)                ; unsorted
 480       ;; Catch and ignore unexpected sorting errors
 481       (condition-case err
 482           (setq file-alist
 483                 (let (index)
 484                   ;; Copy file-alist in case of error
 485                   (sort (copy-sequence file-alist) ; modifies its argument!
 486                         (cond ((memq ?S switches)
 487                                (lambda (x y) ; sorted on size
 488                                  ;; 7th file attribute is file size
 489                                  ;; Make largest file come first
 490                                  (< (nth 7 (cdr y))
 491                                     (nth 7 (cdr x)))))
 492                               ((setq index (ls-lisp-time-index switches))
 493                                (lambda (x y) ; sorted on time
 494                                  (ls-lisp-time-lessp (nth index (cdr y))
 495                                                      (nth index (cdr x)))))
 496                               ((memq ?X switches)
 497                                (lambda (x y) ; sorted on extension
 498                                  (ls-lisp-string-lessp
 499                                   (ls-lisp-extension (car x))
 500                                   (ls-lisp-extension (car y)))))
 501                               (t
 502                                (lambda (x y) ; sorted alphabetically
 503                                  (ls-lisp-string-lessp (car x) (car y))))))))
 504         (error (message "Unsorted (ls-lisp sorting error) - %s"
 505                         (error-message-string err))
 506                (ding) (sit-for 2))))    ; to show user the message!
 507   (if (memq ?F switches)                ; classify switch
 508       (setq file-alist (mapcar 'ls-lisp-classify file-alist)))
 509   (if ls-lisp-dirs-first
 510   ;; Re-sort directories first, without otherwise changing the
 511   ;; ordering, and reverse whole list.  cadr of each element of
 512   ;; `file-alist' is t for directory, string (name linked to) for
 513   ;; symbolic link, or nil.
 514       (let (el dirs files)
 515         (while file-alist
 516           (if (or (eq (cadr (setq el (car file-alist))) t) ; directory
 517                   (and (stringp (cadr el))
 518                        (file-directory-p (cadr el)))) ; symlink to a directory
 519               (setq dirs (cons el dirs))
 520             (setq files (cons el files)))
 521           (setq file-alist (cdr file-alist)))
 522         (setq file-alist
 523               (if (memq ?U switches)    ; unsorted order is reversed
 524                   (nconc dirs files)
 525                 (nconc files dirs)
 526                 ))))
 527   ;; Finally reverse file alist if necessary.
 528   ;; (eq below MUST compare `(not (memq ...))' to force comparison of
 529   ;; `t' or `nil', rather than list tails!)
 530   (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
 531               (not (memq ?r switches))) ; reversed sort order requested
 532           ls-lisp-dirs-first)           ; already reversed
 533       (nreverse file-alist)
 534     file-alist))
 535
 536 (defun ls-lisp-classify-file (filename fattr)
 537   "Append a character to FILENAME indicating the file type.
 538
 539 FATTR is the file attributes returned by `file-attributes' for the file.
 540 The file type indicators are `/' for directories, `@' for symbolic
 541 links, `|' for FIFOs, `=' for sockets, `*' for regular files that
 542 are executable, and nothing for other types of files."
 543   (let* ((type (car fattr))
 544          (modestr (nth 8 fattr))
 545          (typestr (substring modestr 0 1)))
 546     (cond
 547      (type
 548       (concat filename (if (eq type t) "/" "@")))
 549      ((string-match "x" modestr)
 550       (concat filename "*"))
 551      ((string= "p" typestr)
 552       (concat filename "|"))
 553      ((string= "s" typestr)
 554       (concat filename "="))
 555      (t filename))))
 556
 557 (defun ls-lisp-classify (filedata)
 558   "Append a character to file name in FILEDATA indicating the file type.
 559
 560 FILEDATA has the form (FILENAME . ATTRIBUTES), where ATTRIBUTES is the
 561 structure returned by `file-attributes' for that file.
 562
 563 The file type indicators are `/' for directories, `@' for symbolic
 564 links, `|' for FIFOs, `=' for sockets, `*' for regular files that
 565 are executable, and nothing for other types of files."
 566   (let ((file-name (car filedata))
 567         (fattr (cdr filedata)))
 568     (setq file-name (propertize file-name 'dired-filename t))
 569     (cons (ls-lisp-classify-file file-name fattr) fattr)))
 570
 571 (defun ls-lisp-extension (filename)
 572   "Return extension of FILENAME (ignoring any version extension)
 573 FOLLOWED by null and full filename, SOLELY for full alpha sort."
 574   ;; Force extension sort order: `no ext' then `null ext' then `ext'
 575   ;; to agree with GNU ls.
 576   (concat
 577    (let* ((i (length filename)) end)
 578      (if (= (aref filename (1- i)) ?.) ; null extension
 579          "\0"
 580        (while (and (>= (setq i (1- i)) 0)
 581                    (/= (aref filename i) ?.)))
 582        (if (< i 0) "\0\0"               ; no extension
 583          (if (/= (aref filename (1+ i)) ?~)
 584              (substring filename (1+ i))
 585            ;; version extension found -- ignore it
 586            (setq end i)
 587            (while (and (>= (setq i (1- i)) 0)
 588                        (/= (aref filename i) ?.)))
 589            (if (< i 0) "\0\0"   ; no extension
 590              (substring filename (1+ i) end))))
 591        )) "\0" filename))
 592
 593 ;; From Roland McGrath.  Can use this to sort on time.
 594 (defun ls-lisp-time-lessp (time0 time1)
 595   "Return t if time TIME0 is earlier than time TIME1."
 596   (let ((hi0 (car time0)) (hi1 (car time1)))
 597     (or (< hi0 hi1)
 598         (and (= hi0 hi1)
 599              (< (cadr time0) (cadr time1))))))
 600
 601 (defun ls-lisp-format (file-name file-attr file-size switches time-index now)
 602   "Format one line of long ls output for file FILE-NAME.
 603 FILE-ATTR and FILE-SIZE give the file's attributes and size.
 604 SWITCHES, TIME-INDEX and NOW give the full switch list and time data."
 605   (let ((file-type (nth 0 file-attr))
 606         ;; t for directory, string (name linked to)
 607         ;; for symbolic link, or nil.
 608         (drwxrwxrwx (nth 8 file-attr))) ; attribute string ("drwxrwxrwx")
 609     (concat (if (memq ?i switches)      ; inode number
 610                 (let ((inode (nth 10 file-attr)))
 611                   (if (consp inode)
 612                       (if (consp (cdr inode))
 613                           ;; 2^(24+16) = 1099511627776.0, but
 614                           ;; multiplying by it and then adding the
 615                           ;; other members of the cons cell in one go
 616                           ;; loses precision, since a double does not
 617                           ;; have enough significant digits to hold a
 618                           ;; full 64-bit value.  So below we split
 619                           ;; 1099511627776 into high 13 and low 5
 620                           ;; digits and compute in two parts.
 621                           (let ((p1 (* (car inode) 10995116.0))
 622                                 (p2 (+ (* (car inode) 27776.0)
 623                                        (* (cadr inode) 65536.0)
 624                                        (cddr inode))))
 625                             (format " %13.0f%05.0f "
 626                                     ;; Use floor to emulate integer
 627                                     ;; division.
 628                                     (+ p1 (floor p2 100000.0))
 629                                     (mod p2 100000.0)))
 630                         (format " %18.0f "
 631                                 (+ (* (car inode) 65536.0)
 632                                    (cdr inode))))
 633                     (format " %18d " inode))))
 634             ;; nil is treated like "" in concat
 635             (if (memq ?s switches)      ; size in K
 636                 (format ls-lisp-filesize-f-fmt
 637                         (fceiling (/ file-size 1024.0))))
 638             drwxrwxrwx                  ; attribute string
 639             (if (memq 'links ls-lisp-verbosity)
 640                 (format "%3d" (nth 1 file-attr))) ; link count
 641             ;; Numeric uid/gid are more confusing than helpful;
 642             ;; Emacs should be able to make strings of them.
 643             ;; They tend to be bogus on non-UNIX platforms anyway so
 644             ;; optionally hide them.
 645             (if (memq 'uid ls-lisp-verbosity)
 646                 ;; uid can be a string or an integer
 647                 (let ((uid (nth 2 file-attr)))
 648                   (format (if (stringp uid)
 649                               ls-lisp-uid-s-fmt
 650                             ls-lisp-uid-d-fmt)
 651                           uid)))
 652             (if (not (memq ?G switches)) ; GNU ls -- shows group by default
 653                 (if (or (memq ?g switches) ; UNIX ls -- no group by default
 654                         (memq 'gid ls-lisp-verbosity))
 655                     (let ((gid (nth 3 file-attr)))
 656                       (format (if (stringp gid)
 657                                   ls-lisp-gid-s-fmt
 658                                 ls-lisp-gid-d-fmt)
 659                               gid))))
 660             (ls-lisp-format-file-size file-size (memq ?h switches))
 661             " "
 662             (ls-lisp-format-time file-attr time-index now)
 663             " "
 664             (if (not (memq ?F switches)) ; ls-lisp-classify already did that
 665                 (propertize file-name 'dired-filename t)
 666               file-name)
 667             (if (stringp file-type)     ; is a symbolic link
 668                 (concat " -> " file-type))
 669             "\n"
 670             )))
 671
 672 (defun ls-lisp-time-index (switches)
 673   "Return time index into file-attributes according to ls SWITCHES list.
 674 Return nil if no time switch found."
 675   ;; FJW: Default of nil is IMPORTANT and used in `ls-lisp-handle-switches'!
 676   (cond ((memq ?c switches) 6)          ; last mode change
 677         ((memq ?t switches) 5)          ; last modtime
 678         ((memq ?u switches) 4)))        ; last access
 679
 680 (defun ls-lisp-time-to-seconds (time)
 681   "Convert TIME to a floating point number."
 682   (+ (* (car time) 65536.0)
 683      (cadr time)
 684      (/ (or (nth 2 time) 0) 1000000.0)))
 685
 686 (defun ls-lisp-format-time (file-attr time-index now)
 687   "Format time for file with attributes FILE-ATTR according to TIME-INDEX.
 688 Use the same method as ls to decide whether to show time-of-day or year,
 689 depending on distance between file date and NOW.
 690 All ls time options, namely c, t and u, are handled."
 691   (let* ((time (nth (or time-index 5) file-attr)) ; default is last modtime
 692          (diff (- (ls-lisp-time-to-seconds time)
 693                   (ls-lisp-time-to-seconds now)))
 694          ;; Consider a time to be recent if it is within the past six
 695          ;; months.  A Gregorian year has 365.2425 * 24 * 60 * 60 ==
 696          ;; 31556952 seconds on the average, and half of that is 15778476.
 697          ;; Write the constant explicitly to avoid roundoff error.
 698          (past-cutoff -15778476)) ; half a Gregorian year
 699     (condition-case nil
 700         ;; Use traditional time format in the C or POSIX locale,
 701         ;; ISO-style time format otherwise, so columns line up.
 702         (let ((locale system-time-locale))
 703           (if (not locale)
 704               (let ((vars '("LC_ALL" "LC_TIME" "LANG")))
 705                 (while (and vars (not (setq locale (getenv (car vars)))))
 706                   (setq vars (cdr vars)))))
 707           (if (member locale '("C" "POSIX"))
 708               (setq locale nil))
 709           (format-time-string
 710            (if (and (<= past-cutoff diff) (<= diff 0))
 711                (if (and locale (not ls-lisp-use-localized-time-format))
 712                    "%m-%d %H:%M"
 713                  (nth 0 ls-lisp-format-time-list))
 714              (if (and locale (not ls-lisp-use-localized-time-format))
 715                  "%Y-%m-%d "
 716                (nth 1 ls-lisp-format-time-list)))
 717            time))
 718       (error "Unk  0  0000"))))
 719
 720 (defun ls-lisp-format-file-size (file-size human-readable)
 721   (if (not human-readable)
 722       (format (if (floatp file-size)
 723                   ls-lisp-filesize-f-fmt
 724                 ls-lisp-filesize-d-fmt)
 725               file-size)
 726     (if (< file-size 1024)
 727         (format " %4d" file-size)
 728       (do ((file-size (/ file-size 1024.0) (/ file-size 1024.0))
 729            ;; kilo, mega, giga, tera, peta, exa
 730            (post-fixes (list "k" "M" "G" "T" "P" "E") (cdr post-fixes)))
 731           ((< file-size 1024)
 732            (format " %3.0f%s"  file-size (car post-fixes)))))))
 733
 734 (provide 'ls-lisp)
 735
 736 ;; arch-tag: e55f399b-05ec-425c-a6d5-f5e349c35ab4
 737 ;;; ls-lisp.el ends here