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, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29
  30 ;; OVERVIEW ==========================================================
  31
  32 ;; This file redefines the function `insert-directory' to implement it
  33 ;; directly from Emacs lisp, without running ls in a subprocess.  It
  34 ;; is useful if you cannot afford to fork Emacs on a real memory UNIX,
  35 ;; under VMS or other non-UNIX platforms if you don't have the ls
  36 ;; program, or if you want a different format from what ls offers.
  37
  38 ;; This function can use regexps instead of shell wildcards.  If you
  39 ;; enter regexps remember to double each $ sign.  For example, to
  40 ;; include files *.el, enter `.*\.el$$', resulting in the regexp
  41 ;; `.*\.el$'.
  42
  43 ;; RESTRICTIONS ======================================================
  44
  45 ;; * A few obscure ls switches are still ignored: see the docstring of
  46 ;; `insert-directory'.
  47
  48 ;; TO DO =============================================================
  49
  50 ;; Complete handling of F switch (if/when possible).
  51
  52 ;; FJW: May be able to sort much faster by consing the sort key onto
  53 ;; the front of each list element, sorting and then stripping the key
  54 ;; off again!
  55
  56 ;;; History:
  57
  58 ;; Written originally by Sebastian Kremer <sk@thp.uni-koeln.de>
  59 ;; Revised by Andrew Innes and Geoff Volker (and maybe others).
  60
  61 ;; Modified by Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>, mainly
  62 ;; to support many more ls options, "platform emulation" and more
  63 ;; robust sorting.
  64
  65 ;;; Code:
  66
  67 (eval-when-compile (require 'cl))
  68
  69 (defgroup ls-lisp nil
  70   "Emulate the ls program completely in Emacs Lisp."
  71   :version "21.1"
  72   :group 'dired)
  73
  74 (defcustom ls-lisp-emulation
  75   (cond ((eq system-type 'macos) 'MacOS)
  76         ;; ((eq system-type 'windows-nt) 'MS-Windows)
  77         ((memq system-type
  78                '(hpux usg-unix-v unisoft-unix irix berkeley-unix))
  79          'UNIX))                        ; very similar to GNU
  80   ;; Anything else defaults to nil, meaning GNU.
  81   "*Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
  82 Corresponding value is one of the atoms: nil, MacOS, MS-Windows, UNIX.
  83 Sets default values for: `ls-lisp-ignore-case', `ls-lisp-dirs-first',
  84 `ls-lisp-verbosity'.  Need not match actual platform.  Changing this
  85 option will have no effect until you restart Emacs."
  86   :type '(choice (const :tag "GNU" nil)
  87                  (const MacOS)
  88                  (const MS-Windows)
  89                  (const UNIX))
  90   :group 'ls-lisp)
  91
  92 (defcustom ls-lisp-ignore-case
  93   ;; Name change for consistency with other option names.
  94   (or (memq ls-lisp-emulation '(MS-Windows MacOS))
  95       (and (boundp 'ls-lisp-dired-ignore-case) ls-lisp-dired-ignore-case))
  96   "*Non-nil causes ls-lisp alphabetic sorting to ignore case."
  97   :type 'boolean
  98   :group 'ls-lisp)
  99
 100 (defcustom ls-lisp-dirs-first (eq ls-lisp-emulation 'MS-Windows)
 101   "*Non-nil causes ls-lisp to sort directories first in any ordering.
 102 \(Or last if it is reversed.)  Follows Microsoft Windows Explorer."
 103   ;; Functionality suggested by Chris McMahan <cmcmahan@one.net>
 104   :type 'boolean
 105   :group 'ls-lisp)
 106
 107 (defcustom ls-lisp-verbosity
 108   (cond ((eq ls-lisp-emulation 'MacOS) nil)
 109         ((eq ls-lisp-emulation 'MS-Windows)
 110          (if (and (fboundp 'w32-using-nt) (w32-using-nt))
 111              '(links)))                 ; distinguish NT/2K from 9x
 112         ((eq ls-lisp-emulation 'UNIX) '(links uid)) ; UNIX ls
 113         (t '(links uid gid)))           ; GNU ls
 114   "*A list of optional file attributes that ls-lisp should display.
 115 It should contain none or more of the symbols: links, uid, gid.
 116 A value of nil (or an empty list) means display none of them.
 117
 118 Concepts come from UNIX: `links' means count of names associated with
 119 the file\; `uid' means user (owner) identifier\; `gid' means group
 120 identifier.
 121
 122 If emulation is MacOS then default is nil\;
 123 if emulation is MS-Windows then default is `(links)' if platform is
 124 Windows NT/2K, nil otherwise\;
 125 if emulation is UNIX then default is `(links uid)'\;
 126 if emulation is GNU then default is `(links uid gid)'."
 127   ;; Functionality suggested by Howard Melman <howard@silverstream.com>
 128   :type '(set (const :tag "Show Link Count" links)
 129               (const :tag "Show User" uid)
 130               (const :tag "Show Group" gid))
 131   :group 'ls-lisp)
 132
 133 (defcustom ls-lisp-use-insert-directory-program
 134   (not (memq system-type '(macos ms-dos windows-nt)))
 135   "*Non-nil causes ls-lisp to revert back to using `insert-directory-program'.
 136 This is useful on platforms where ls-lisp is dumped into Emacs, such as
 137 Microsoft Windows, but you would still like to use a program to list
 138 the contents of a directory."
 139   :type 'boolean
 140   :group 'ls-lisp)
 141
 142 ;;; Autoloaded because it is let-bound in `recover-session', `mail-recover-1'.
 143 ;;;###autoload
 144 (defcustom ls-lisp-support-shell-wildcards t
 145   "*Non-nil means ls-lisp treats file patterns as shell wildcards.
 146 Otherwise they are treated as Emacs regexps (for backward compatibility)."
 147   :type 'boolean
 148   :group 'ls-lisp)
 149
 150 (defcustom ls-lisp-format-time-list
 151   '("%b %e %H:%M"
 152     "%b %e  %Y")
 153   "*List of `format-time-string' specs to display file time stamps.
 154 These specs are used ONLY if a valid locale can not be determined.
 155
 156 If `ls-lisp-use-localized-time-format' is non-nil, these specs are used
 157 regardless of whether the locale can be determined.
 158
 159 Syntax:  (EARLY-TIME-FORMAT OLD-TIME-FORMAT)
 160
 161 The EARLY-TIME-FORMAT is used if file has been modified within the
 162 current year. The OLD-TIME-FORMAT is used for older files.  To use ISO
 163 8601 dates, you could set:
 164
 165 \(setq ls-lisp-format-time-list
 166        '(\"%Y-%m-%d %H:%M\"
 167          \"%Y-%m-%d      \"))"
 168   :type '(list (string :tag "Early time format")
 169                (string :tag "Old time format"))
 170   :group 'ls-lisp)
 171
 172 (defcustom ls-lisp-use-localized-time-format nil
 173   "*Non-nil causes ls-lisp to use `ls-lisp-format-time-list' even if
 174 a valid locale is specified.
 175
 176 WARNING: Using localized date/time format might cause Dired columns
 177 to fail to lign up, e.g. if month names are not all of the same length."
 178   :type 'boolean
 179   :group 'ls-lisp)
 180
 181 (defvar original-insert-directory nil
 182   "This holds the original function definition of `insert-directory'.")
 183
 184 ;; Remember the original insert-directory function
 185 (or (featurep 'ls-lisp)  ; FJW: unless this file is being reloaded!
 186     (setq original-insert-directory (symbol-function 'insert-directory)))
 187
 188 \f
 189 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 190
 191 (defun insert-directory (file switches &optional wildcard full-directory-p)
 192   "Insert directory listing for FILE, formatted according to SWITCHES.
 193 Leaves point after the inserted text.
 194 SWITCHES may be a string of options, or a list of strings.
 195 Optional third arg WILDCARD means treat FILE as shell wildcard.
 196 Optional fourth arg FULL-DIRECTORY-P means file is a directory and
 197 switches do not contain `d', so that a full listing is expected.
 198
 199 This version of the function comes from `ls-lisp.el'.
 200 If the value of `ls-lisp-use-insert-directory-program' is non-nil then
 201 it works exactly like the version from `files.el' and runs a directory
 202 listing program whose name is in the variable
 203 `insert-directory-program'; if also WILDCARD is non-nil then it runs
 204 the shell specified by `shell-file-name'.  If the value of
 205 `ls-lisp-use-insert-directory-program' is nil then it runs a Lisp
 206 emulation.
 207
 208 The Lisp emulation does not run any external programs or shells.  It
 209 supports ordinary shell wildcards if `ls-lisp-support-shell-wildcards'
 210 is non-nil; otherwise, it interprets wildcards as regular expressions
 211 to match file names.  It does not support all `ls' switches -- those
 212 that work are: A a c i r S s t u U X g G B C R n and F partly."
 213   (if ls-lisp-use-insert-directory-program
 214       (funcall original-insert-directory
 215                file switches wildcard full-directory-p)
 216     ;; We need the directory in order to find the right handler.
 217     (let ((handler (find-file-name-handler (expand-file-name file)
 218                                            'insert-directory))
 219           (orig-file file)
 220           wildcard-regexp)
 221       (if handler
 222           (funcall handler 'insert-directory file switches
 223                    wildcard full-directory-p)
 224         ;; Remove --dired switch
 225         (if (string-match "--dired " switches)
 226             (setq switches (replace-match "" nil nil switches)))
 227         ;; Convert SWITCHES to a list of characters.
 228         (setq switches (delete ?- (append switches nil)))
 229         ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
 230         ;; `ls' don't mind, we certainly do, because it makes us think
 231         ;; there is no wildcard, only a directory name.
 232         (if (and ls-lisp-support-shell-wildcards
 233                  (string-match "[[?*]" file)
 234                  ;; Prefer an existing file to wildcards, like
 235                  ;; dired-noselect does.
 236                  (not (file-exists-p file)))
 237             (progn
 238               (or (not (eq (aref file (1- (length file))) ?/))
 239                   (setq file (substring file 0 (1- (length file)))))
 240               (setq wildcard t)))
 241         (if wildcard
 242             (setq wildcard-regexp
 243                   (if ls-lisp-support-shell-wildcards
 244                       (wildcard-to-regexp (file-name-nondirectory file))
 245                     (file-name-nondirectory file))
 246                   file (file-name-directory file))
 247           (if (memq ?B switches) (setq wildcard-regexp "[^~]\\'")))
 248         (condition-case err
 249             (ls-lisp-insert-directory
 250              file switches (ls-lisp-time-index switches)
 251              wildcard-regexp full-directory-p)
 252           (invalid-regexp
 253            ;; Maybe they wanted a literal file that just happens to
 254            ;; use characters special to shell wildcards.
 255            (if (equal (cadr err) "Unmatched [ or [^")
 256                (progn
 257                  (setq wildcard-regexp (if (memq ?B switches) "[^~]\\'")
 258                        file (file-relative-name orig-file))
 259                  (ls-lisp-insert-directory
 260                   file switches (ls-lisp-time-index switches)
 261                   nil full-directory-p))
 262              (signal (car err) (cdr err)))))
 263         ;; Try to insert the amount of free space.
 264         (save-excursion
 265           (goto-char (point-min))
 266           ;; First find the line to put it on.
 267           (when (re-search-forward "^total" nil t)
 268             (let ((available (get-free-disk-space ".")))
 269               (when available
 270                 ;; Replace "total" with "total used", to avoid confusion.
 271                 (replace-match "total used in directory")
 272                 (end-of-line)
 273                 (insert " available " available)))))))))
 274
 275 (defun ls-lisp-insert-directory
 276   (file switches time-index wildcard-regexp full-directory-p)
 277   "Insert directory listing for FILE, formatted according to SWITCHES.
 278 Leaves point after the inserted text.  This is an internal function
 279 optionally called by the `ls-lisp.el' version of `insert-directory'.
 280 It is called recursively if the -R switch is used.
 281 SWITCHES is a *list* of characters.  TIME-INDEX is the time index into
 282 file-attributes according to SWITCHES.  WILDCARD-REGEXP is nil or an *Emacs
 283 regexp*.  FULL-DIRECTORY-P means file is a directory and SWITCHES does
 284 not contain `d', so that a full listing is expected."
 285   (if (or wildcard-regexp full-directory-p)
 286       (let* ((dir (file-name-as-directory file))
 287              (default-directory dir)    ; so that file-attributes works
 288              (file-alist
 289               (directory-files-and-attributes dir nil wildcard-regexp t
 290                                               (if (memq ?n switches)
 291                                                   'integer
 292                                                 'string)))
 293              (now (current-time))
 294              (sum 0)
 295              ;; do all bindings here for speed
 296              total-line files elt short file-size fil attr)
 297         (cond ((memq ?A switches)
 298                (setq file-alist
 299                      (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
 300               ((not (memq ?a switches))
 301                ;; if neither -A  nor -a, flush . files
 302                (setq file-alist
 303                      (ls-lisp-delete-matching "^\\." file-alist))))
 304         (setq file-alist
 305               (ls-lisp-handle-switches file-alist switches))
 306         (if (memq ?C switches)          ; column (-C) format
 307             (ls-lisp-column-format file-alist)
 308           (setq total-line (cons (point) (car-safe file-alist)))
 309           (setq files file-alist)
 310           (while files                  ; long (-l) format
 311             (setq elt (car files)
 312                   files (cdr files)
 313                   short (car elt)
 314                   attr (cdr elt)
 315                   file-size (nth 7 attr))
 316             (and attr
 317                  (setq sum (+ file-size
 318                               ;; Even if neither SUM nor file's size
 319                               ;; overflow, their sum could.
 320                               (if (or (< sum (- 134217727 file-size))
 321                                       (floatp sum)
 322                                       (floatp file-size))
 323                                   sum
 324                                 (float sum))))
 325                  (insert (ls-lisp-format short attr file-size
 326                                          switches time-index now))))
 327           ;; Insert total size of all files:
 328           (save-excursion
 329             (goto-char (car total-line))
 330             (or (cdr total-line)
 331                 ;; Shell says ``No match'' if no files match
 332                 ;; the wildcard; let's say something similar.
 333                 (insert "(No match)\n"))
 334             (insert (format "total %.0f\n" (fceiling (/ sum 1024.0))))))
 335         (if (memq ?R switches)
 336             ;; List the contents of all directories recursively.
 337             ;; cadr of each element of `file-alist' is t for
 338             ;; directory, string (name linked to) for symbolic
 339             ;; link, or nil.
 340             (while file-alist
 341               (setq elt (car file-alist)
 342                     file-alist (cdr file-alist))
 343               (when (and (eq (cadr elt) t) ; directory
 344                          (not (string-match "\\`\\.\\.?\\'" (car elt))))
 345                 (setq elt (expand-file-name (car elt) dir))
 346                 (insert "\n" elt ":\n")
 347                 (ls-lisp-insert-directory
 348                  elt switches time-index wildcard-regexp full-directory-p)))))
 349     ;; If not full-directory-p, FILE *must not* end in /, as
 350     ;; file-attributes will not recognize a symlink to a directory,
 351     ;; so must make it a relative filename as ls does:
 352     (if (eq (aref file (1- (length file))) ?/)
 353         (setq file (substring file 0 -1)))
 354     (let ((fattr (file-attributes file 'string)))
 355       (if fattr
 356           (insert (ls-lisp-format file fattr (nth 7 fattr)
 357                                   switches time-index (current-time)))
 358         (message "%s: doesn't exist or is inaccessible" file)
 359         (ding) (sit-for 2)))))          ; to show user the message!
 360
 361 (defun ls-lisp-column-format (file-alist)
 362   "Insert the file names (only) in FILE-ALIST into the current buffer.
 363 Format in columns, sorted vertically, following GNU ls -C.
 364 Responds to the window width as ls should but may not!"
 365   (let (files fmt ncols collen (nfiles 0) (colwid 0))
 366     ;; Count number of files as `nfiles', build list of filenames as
 367     ;; `files', and find maximum filename length as `colwid':
 368     (let (file len)
 369       (while file-alist
 370         (setq nfiles (1+ nfiles)
 371               file (caar file-alist)
 372               files (cons file files)
 373               file-alist (cdr file-alist)
 374               len (length file))
 375         (if (> len colwid) (setq colwid len))))
 376     (setq files (nreverse files)
 377           colwid (+ 2 colwid)           ; 2 character column gap
 378           fmt (format "%%-%ds" colwid)  ; print format
 379           ncols (/ (window-width) colwid) ; no of columns
 380           collen (/ nfiles ncols))      ; floor of column length
 381     (if (> nfiles (* collen ncols)) (setq collen (1+ collen)))
 382     ;; Output the file names in columns, sorted vertically:
 383     (let ((i 0) j)
 384       (while (< i collen)
 385         (setq j i)
 386         (while (< j nfiles)
 387           (insert (format fmt (nth j files)))
 388           (setq j (+ j collen)))
 389         ;; FJW: This is completely unnecessary, but I don't like
 390         ;; trailing white space...
 391         (delete-region (point) (progn (skip-chars-backward " \t") (point)))
 392         (insert ?\n)
 393         (setq i (1+ i))))))
 394
 395 (defun ls-lisp-delete-matching (regexp list)
 396   "Delete all elements matching REGEXP from LIST, return new list."
 397   ;; Should perhaps use setcdr for efficiency.
 398   (let (result)
 399     (while list
 400       (or (string-match regexp (caar list))
 401           (setq result (cons (car list) result)))
 402       (setq list (cdr list)))
 403     result))
 404
 405 (defsubst ls-lisp-string-lessp (s1 s2)
 406   "Return t if string S1 is less than string S2 in lexicographic order.
 407 Case is significant if `ls-lisp-ignore-case' is nil.
 408 Unibyte strings are converted to multibyte for comparison."
 409   (let ((u (compare-strings s1 0 nil s2 0 nil ls-lisp-ignore-case)))
 410     (and (numberp u) (< u 0))))
 411
 412 (defun ls-lisp-handle-switches (file-alist switches)
 413   "Return new FILE-ALIST sorted according to SWITCHES.
 414 SWITCHES is a list of characters.  Default sorting is alphabetic."
 415   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
 416   (or (memq ?U switches)                ; unsorted
 417       ;; Catch and ignore unexpected sorting errors
 418       (condition-case err
 419           (setq file-alist
 420                 (let (index)
 421                   ;; Copy file-alist in case of error
 422                   (sort (copy-sequence file-alist) ; modifies its argument!
 423                         (cond ((memq ?S switches)
 424                                (lambda (x y) ; sorted on size
 425                                  ;; 7th file attribute is file size
 426                                  ;; Make largest file come first
 427                                  (< (nth 7 (cdr y))
 428                                     (nth 7 (cdr x)))))
 429                               ((setq index (ls-lisp-time-index switches))
 430                                (lambda (x y) ; sorted on time
 431                                  (ls-lisp-time-lessp (nth index (cdr y))
 432                                                      (nth index (cdr x)))))
 433                               ((memq ?X switches)
 434                                (lambda (x y) ; sorted on extension
 435                                  (ls-lisp-string-lessp
 436                                   (ls-lisp-extension (car x))
 437                                   (ls-lisp-extension (car y)))))
 438                               (t
 439                                (lambda (x y) ; sorted alphabetically
 440                                  (ls-lisp-string-lessp (car x) (car y))))))))
 441         (error (message "Unsorted (ls-lisp sorting error) - %s"
 442                         (error-message-string err))
 443                (ding) (sit-for 2))))    ; to show user the message!
 444   (if (memq ?F switches)                ; classify switch
 445       (setq file-alist (mapcar 'ls-lisp-classify file-alist)))
 446   (if ls-lisp-dirs-first
 447   ;; Re-sort directories first, without otherwise changing the
 448   ;; ordering, and reverse whole list.  cadr of each element of
 449   ;; `file-alist' is t for directory, string (name linked to) for
 450   ;; symbolic link, or nil.
 451       (let (el dirs files)
 452         (while file-alist
 453           (if (or (eq (cadr (setq el (car file-alist))) t) ; directory
 454                   (and (stringp (cadr el))
 455                        (file-directory-p (cadr el)))) ; symlink to a directory
 456               (setq dirs (cons el dirs))
 457             (setq files (cons el files)))
 458           (setq file-alist (cdr file-alist)))
 459         (setq file-alist
 460               (if (memq ?U switches)    ; unsorted order is reversed
 461                   (nconc dirs files)
 462                 (nconc files dirs)
 463                 ))))
 464   ;; Finally reverse file alist if necessary.
 465   ;; (eq below MUST compare `(not (memq ...))' to force comparison of
 466   ;; `t' or `nil', rather than list tails!)
 467   (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
 468               (not (memq ?r switches))) ; reversed sort order requested
 469           ls-lisp-dirs-first)           ; already reversed
 470       (nreverse file-alist)
 471     file-alist))
 472
 473 (defun ls-lisp-classify (filedata)
 474   "Append a character to each file name indicating the file type.
 475 Also, for regular files that are executable, append `*'.
 476 The file type indicators are `/' for directories, `@' for symbolic
 477 links, `|' for FIFOs, `=' for sockets, and nothing for regular files.
 478 \[But FIFOs and sockets are not recognized.]
 479 FILEDATA has the form (filename . `file-attributes').  Its `cadr' is t
 480 for directory, string (name linked to) for symbolic link, or nil."
 481   (let ((file-name (car filedata))
 482         (type (cadr filedata)))
 483     (cond (type
 484            (cons
 485             (concat file-name (if (eq type t) "/" "@"))
 486             (cdr filedata)))
 487           ((string-match "x" (nth 9 filedata))
 488            (cons
 489             (concat file-name "*")
 490             (cdr filedata)))
 491           (t filedata))))
 492
 493 (defun ls-lisp-extension (filename)
 494   "Return extension of FILENAME (ignoring any version extension)
 495 FOLLOWED by null and full filename, SOLELY for full alpha sort."
 496   ;; Force extension sort order: `no ext' then `null ext' then `ext'
 497   ;; to agree with GNU ls.
 498   (concat
 499    (let* ((i (length filename)) end)
 500      (if (= (aref filename (1- i)) ?.) ; null extension
 501          "\0"
 502        (while (and (>= (setq i (1- i)) 0)
 503                    (/= (aref filename i) ?.)))
 504        (if (< i 0) "\0\0"               ; no extension
 505          (if (/= (aref filename (1+ i)) ?~)
 506              (substring filename (1+ i))
 507            ;; version extension found -- ignore it
 508            (setq end i)
 509            (while (and (>= (setq i (1- i)) 0)
 510                        (/= (aref filename i) ?.)))
 511            (if (< i 0) "\0\0"   ; no extension
 512              (substring filename (1+ i) end))))
 513        )) "\0" filename))
 514
 515 ;; From Roland McGrath.  Can use this to sort on time.
 516 (defun ls-lisp-time-lessp (time0 time1)
 517   "Return t if time TIME0 is earlier than time TIME1."
 518   (let ((hi0 (car time0)) (hi1 (car time1)))
 519     (or (< hi0 hi1)
 520         (and (= hi0 hi1)
 521              (< (cadr time0) (cadr time1))))))
 522
 523 (defun ls-lisp-format (file-name file-attr file-size switches time-index now)
 524   "Format one line of long ls output for file FILE-NAME.
 525 FILE-ATTR and FILE-SIZE give the file's attributes and size.
 526 SWITCHES, TIME-INDEX and NOW give the full switch list and time data."
 527   (let ((file-type (nth 0 file-attr))
 528         ;; t for directory, string (name linked to)
 529         ;; for symbolic link, or nil.
 530         (drwxrwxrwx (nth 8 file-attr))) ; attribute string ("drwxrwxrwx")
 531     (concat (if (memq ?i switches)      ; inode number
 532                 (format " %6d" (nth 10 file-attr)))
 533             ;; nil is treated like "" in concat
 534             (if (memq ?s switches)      ; size in K
 535                 (format " %4.0f" (fceiling (/ file-size 1024.0))))
 536             drwxrwxrwx                  ; attribute string
 537             (if (memq 'links ls-lisp-verbosity)
 538                 (format " %3d" (nth 1 file-attr))) ; link count
 539             ;; Numeric uid/gid are more confusing than helpful;
 540             ;; Emacs should be able to make strings of them.
 541             ;; They tend to be bogus on non-UNIX platforms anyway so
 542             ;; optionally hide them.
 543             (if (memq 'uid ls-lisp-verbosity)
 544                 ;; uid can be a sting or an integer
 545                 (let ((uid (nth 2 file-attr)))
 546                   (format (if (stringp uid) " %-8s" " %-8d") uid)))
 547             (if (not (memq ?G switches)) ; GNU ls -- shows group by default
 548                 (if (or (memq ?g switches) ; UNIX ls -- no group by default
 549                         (memq 'gid ls-lisp-verbosity))
 550                     (let ((gid (nth 3 file-attr)))
 551                       (format (if (stringp gid) " %-8s" " %-8d") gid))))
 552             (ls-lisp-format-file-size file-size (memq ?h switches))
 553             " "
 554             (ls-lisp-format-time file-attr time-index now)
 555             " "
 556             (propertize file-name 'dired-filename t)
 557             (if (stringp file-type)     ; is a symbolic link
 558                 (concat " -> " file-type))
 559             "\n"
 560             )))
 561
 562 (defun ls-lisp-time-index (switches)
 563   "Return time index into file-attributes according to ls SWITCHES list.
 564 Return nil if no time switch found."
 565   ;; FJW: Default of nil is IMPORTANT and used in `ls-lisp-handle-switches'!
 566   (cond ((memq ?c switches) 6)          ; last mode change
 567         ((memq ?t switches) 5)          ; last modtime
 568         ((memq ?u switches) 4)))        ; last access
 569
 570 (defun ls-lisp-time-to-seconds (time)
 571   "Convert TIME to a floating point number."
 572   (+ (* (car time) 65536.0)
 573      (cadr time)
 574      (/ (or (nth 2 time) 0) 1000000.0)))
 575
 576 (defun ls-lisp-format-time (file-attr time-index now)
 577   "Format time for file with attributes FILE-ATTR according to TIME-INDEX.
 578 Use the same method as ls to decide whether to show time-of-day or year,
 579 depending on distance between file date and NOW.
 580 All ls time options, namely c, t and u, are handled."
 581   (let* ((time (nth (or time-index 5) file-attr)) ; default is last modtime
 582          (diff (- (ls-lisp-time-to-seconds time)
 583                   (ls-lisp-time-to-seconds now)))
 584          ;; Consider a time to be recent if it is within the past six
 585          ;; months.  A Gregorian year has 365.2425 * 24 * 60 * 60 ==
 586          ;; 31556952 seconds on the average, and half of that is 15778476.
 587          ;; Write the constant explicitly to avoid roundoff error.
 588          (past-cutoff -15778476)) ; half a Gregorian year
 589     (condition-case nil
 590         ;; Use traditional time format in the C or POSIX locale,
 591         ;; ISO-style time format otherwise, so columns line up.
 592         (let ((locale system-time-locale))
 593           (if (not locale)
 594               (let ((vars '("LC_ALL" "LC_TIME" "LANG")))
 595                 (while (and vars (not (setq locale (getenv (car vars)))))
 596                   (setq vars (cdr vars)))))
 597           (if (member locale '("C" "POSIX"))
 598               (setq locale nil))
 599           (format-time-string
 600            (if (and (<= past-cutoff diff) (<= diff 0))
 601                (if (and locale (not ls-lisp-use-localized-time-format))
 602                    "%m-%d %H:%M"
 603                  (nth 0 ls-lisp-format-time-list))
 604              (if (and locale (not ls-lisp-use-localized-time-format))
 605                  "%Y-%m-%d "
 606                (nth 1 ls-lisp-format-time-list)))
 607            time))
 608       (error "Unk  0  0000"))))
 609
 610 (defun ls-lisp-format-file-size (file-size human-readable)
 611   (if (or (not human-readable)
 612           (< file-size 1024))
 613       (format (if (floatp file-size) " %9.0f" " %9d") file-size)
 614     (do ((file-size (/ file-size 1024.0) (/ file-size 1024.0))
 615          ;; kilo, mega, giga, tera, peta, exa
 616          (post-fixes (list "k" "M" "G" "T" "P" "E") (cdr post-fixes)))
 617         ((< file-size 1024) (format " %8.0f%s"  file-size (car post-fixes))))))
 618
 619 (provide 'ls-lisp)
 620
 621 ;;; arch-tag: e55f399b-05ec-425c-a6d5-f5e349c35ab4
 622 ;;; ls-lisp.el ends here