From Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>:

Better support for the Mac and MS-Windows.
(ls-lisp): New defgroup.
(ls-lisp-emulation, ls-lisp-ignore-case, ls-lisp-dirs-first)
(ls-lisp-verbosity, ls-lisp-use-insert-directory-program)
(ls-lisp-support-shell-wildcards): New defcustoms.
(ls-lisp-parse-symlink): New function.
(insert-directory): Code to convert switches to a list and set up
the wildcard argument copied from ls-lisp-insert-directory.
(ls-lisp-insert-directory): New argument TIME-INDEX.  Add support
for -C and -R switches.
(ls-lisp-column-format): New function.
(ls-lisp-delete-matching, ls-lisp-handle-switches)
(ls-lisp-format-time): Add doc strings.
(ls-lisp-handle-switches): Handle -U, -S, -X, and -F switches.
Support ls-lisp-dirs-first.
(ls-lisp-classify, ls-lisp-extension): New functions.
(ls-lisp-format): Optionally support emulation of symlinks.
Support -i, -s, and -G switches.

1 files changed, 443 insertions, 216 deletions

diff --git a/lisp/ls-lisp.el b/lisp/ls-lisp.el
index fa7b462b3ff..67b87c0be55 100644
--- a/lisp/ls-lisp.el
+++ b/lisp/ls-lisp.el
@@ -1,10 +1,11 @@
 ;;; ls-lisp.el --- emulate insert-directory completely in Emacs Lisp
 
-;; Copyright (C) 1992, 1994 Free Software Foundation, Inc.
+;; Copyright (C) 1992, 1994, 2000 Free Software Foundation, Inc.
 
-;; Author: Sebastian Kremer <sk@thp.uni-koeln.de>
-;; Maintainer: FSF
-;; Keywords: unix
+;; Author:              Sebastian Kremer <sk@thp.uni-koeln.de>
+;; Modified by:         Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>
+;; Maintainer:          FSF
+;; Keywords:            unix, dired
 
 ;; This file is part of GNU Emacs.
 
@@ -25,55 +26,137 @@
 
 ;;; Commentary:
 
-;; INSTALLATION =======================================================
-;; 
-;; Put this file into your load-path.  To use it, load it
-;; with (load "ls-lisp").
+;; OVERVIEW ==========================================================
 
-;; OVERVIEW ===========================================================
+;; This file redefines the function `insert-directory' to implement it
+;; directly from Emacs lisp, without running ls in a subprocess.  It
+;; is useful if you cannot afford to fork Emacs on a real memory UNIX,
+;; under VMS or other non-UNIX platforms if you don't have the ls
+;; program, or if you want a different format from what ls offers.
 
-;; This file overloads the function insert-directory to implement it
-;; directly from Emacs lisp, without running `ls' in a subprocess.
+;; This function can use regexps instead of shell wildcards.  If you
+;; enter regexps remember to double each $ sign.  For example, to
+;; include files *.el, enter `.*\.el$$', resulting in the regexp
+;; `.*\.el$'.
 
-;; It is useful if you cannot afford to fork Emacs on a real memory UNIX,
-;; under VMS, or if you don't have the ls program, or if you want
-;; different format from what ls offers.
+;; RESTRICTIONS ======================================================
 
-;; This function uses regexps instead of shell
-;; wildcards.  If you enter regexps remember to double each $ sign.
-;; For example, to include files *.el, enter `.*\.el$$',
-;; resulting in the regexp `.*\.el$'.
+;; * A few obscure ls switches are still ignored: see the docstring of
+;; `insert-directory'.
 
-;;  RESTRICTIONS =====================================================
+;; * Generally only numeric uid/gid.
 
-;; * many ls switches are ignored, see docstring of `insert-directory'.
+;; TO DO =============================================================
 
-;; * Only numeric uid/gid
+;; Complete handling of F switch (if/when possible).
 
-;; TODO ==============================================================
+;; FJW: May be able to sort much faster by consing the sort key onto
+;; the front of each list element, sorting and then stripping the key
+;; off again!
 
-;; Recognize some more ls switches: R F
-
-;;; Code:
+;;; History:
 
-;;;###autoload
-(defvar ls-lisp-support-shell-wildcards t
-  "*Non-nil means file patterns are treated as shell wildcards.
-nil means they are treated as Emacs regexps (for backward compatibility).
-This variable is checked by \\[insert-directory] only when `ls-lisp.el'
-package is used.")
+;; Written originally by Sebastian Kremer <sk@thp.uni-koeln.de>
+;; Revised by Andrew Innes and Geoff Volker (and maybe others).
 
-(defvar ls-lisp-dired-ignore-case nil
-  "Non-nil causes dired buffers to sort alphabetically regardless of case.")
+;; Modified by Francis J. Wright <F.J.Wright@maths.qmw.ac.uk>, mainly
+;; to support many more ls options, "platform emulation", hooks for
+;; external symbolic link support and more robust sorting.
+
+;;; Code:
 
-(defvar ls-lisp-use-insert-directory-program nil
-  "Non-nil causes ls-lisp to revert back to using `insert-directory-program'.
+;;;###autoload
+(defgroup ls-lisp nil
+  "Emulate the ls program completely in Emacs Lisp."
+  :group 'dired)
+
+(defcustom ls-lisp-emulation
+  (cond ((eq system-type 'macos) 'MacOS)
+        ;; ((eq system-type 'windows-nt) 'MS-Windows)
+        ((memq system-type
+               '(hpux dgux usg-unix-v unisoft-unix rtu irix berkeley-unix))
+         'UNIX))                        ; very similar to GNU
+  ;; Anything else defaults to nil, meaning GNU.
+  "*Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
+Corresponding value is one of the atoms: nil, MacOS, MS-Windows, UNIX.
+Sets default values for: `ls-lisp-ignore-case', `ls-lisp-dirs-first',
+`ls-lisp-verbosity'.  Need not match actual platform.  Changing this
+option will have no effect until you restart Emacs."
+  :type '(choice (const :tag "GNU" nil)
+                 (const MacOS)
+                 (const MS-Windows)
+                 (const UNIX))
+  :group 'ls-lisp)
+
+(defcustom ls-lisp-ignore-case
+  ;; Name change for consistency with other option names.
+  (or (memq ls-lisp-emulation '(MS-Windows MacOS))
+      (and (boundp 'ls-lisp-dired-ignore-case) ls-lisp-dired-ignore-case))
+  "*Non-nil causes ls-lisp alphabetic sorting to ignore case."
+  :type 'boolean
+  :group 'ls-lisp)
+
+(defcustom ls-lisp-dirs-first (eq ls-lisp-emulation 'MS-Windows)
+  "*Non-nil causes ls-lisp to sort directories first in any ordering.
+\(Or last if it is reversed.)  Follows Microsoft Windows Explorer."
+  ;; Functionality suggested by Chris McMahan <cmcmahan@one.net>
+  :type 'boolean
+  :group 'ls-lisp)
+
+(defcustom ls-lisp-verbosity
+  (cond ((eq ls-lisp-emulation 'MacOS) nil)
+        ((eq ls-lisp-emulation 'MS-Windows)
+         (if (and (fboundp 'w32-using-nt) (w32-using-nt))
+             '(links)))                 ; distinguish NT/2K from 9x
+        ((eq ls-lisp-emulation 'UNIX) '(links uid)) ; UNIX ls
+        (t '(links uid gid)))           ; GNU ls
+  "*A list of optional file attributes that ls-lisp should display.
+It should contain none or more of the symbols: links, uid, gid.
+Nil (or an empty list) means display none of them.
+
+Concepts come from UNIX: `links' means count of names associated with
+the file\; `uid' means user (owner) identifier\; `gid' means group
+identifier.
+
+If emulation is MacOS then default is nil\;
+if emulation is MS-Windows then default is `(links)' if platform is
+Windows NT/2K, nil otherwise\;
+if emulation is UNIX then default is `(links uid)'\;
+if emulation is GNU then default is `(links uid gid)'."
+  ;; Functionality suggested by Howard Melman <howard@silverstream.com>
+  :type '(set (const :tag "Show Link Count" links)
+              (const :tag "Show User" uid)
+              (const :tag "Show Group" gid))
+  :group 'ls-lisp)
+
+(defcustom ls-lisp-use-insert-directory-program nil
+  "*Non-nil causes ls-lisp to revert back to using `insert-directory-program'.
 This is useful on platforms where ls-lisp is dumped into Emacs, such as
 Microsoft Windows, but you would still like to use a program to list
-the contents of a directory.")
+the contents of a directory."
+  :type 'boolean
+  :group 'ls-lisp)
+
+(defcustom ls-lisp-support-shell-wildcards t
+  "*Non-nil means ls-lisp treats file patterns as shell wildcards.
+Otherwise they are treated as Emacs regexps (for backward compatibility)."
+  :type 'boolean
+  :group 'ls-lisp)
+
+;; Remember the original insert-directory function
+(or (featurep 'ls-lisp)  ; FJW: unless this file is being reloaded!
+    (fset 'original-insert-directory (symbol-function 'insert-directory)))
+
+;; This stub is to allow ls-lisp to parse symbolic links via another
+;; library such as w32-symlinks.el from
+;; http://centaur.qmw.ac.uk/Emacs/:
+(defun ls-lisp-parse-symlink (file-name)
+  "This stub may be redefined to parse FILE-NAME as a symlink.
+It should return nil or the link target as a string."
+  nil)
 
-;; Remember the original insert-directory function.
-(fset 'original-insert-directory (symbol-function 'insert-directory))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (defun insert-directory (file switches &optional wildcard full-directory-p)
   "Insert directory listing for FILE, formatted according to SWITCHES.
@@ -83,216 +166,360 @@ Optional third arg WILDCARD means treat FILE as shell wildcard.
 Optional fourth arg FULL-DIRECTORY-P means file is a directory and
 switches do not contain `d', so that a full listing is expected.
 
-This version of the function comes from `ls-lisp.el'.  Depending upon
-the value of `ls-lisp-use-insert-directory-program', it will use an
-external program if non-nil or the lisp function `ls-lisp-insert-directory'
-otherwise."
+This version of the function comes from `ls-lisp.el'.
+If the value of `ls-lisp-use-insert-directory-program' is non-nil then
+it works exactly like the version from `files.el' and runs a directory
+listing program whose name is in the variable
+`insert-directory-program'; if also WILDCARD is non-nil then it runs
+the shell specified by `shell-file-name'.  If the value of
+`ls-lisp-use-insert-directory-program' is nil then it runs a Lisp
+emulation.
+
+The Lisp emulation does not run any external programs or shells.  It
+supports ordinary shell wildcards if `ls-lisp-support-shell-wildcards'
+is non-nil; otherwise, it interprets wildcards as regular expressions
+to match file names.  It does not support all `ls' switches -- those
+that work are: A a c i r S s t u U X g G B C R and F partly."
   (if ls-lisp-use-insert-directory-program
       (original-insert-directory file switches wildcard full-directory-p)
-    (ls-lisp-insert-directory file switches wildcard full-directory-p)))
-
-(defun ls-lisp-insert-directory (file switches &optional wildcard full-directory-p)
+    ;; We need the directory in order to find the right handler.
+    (let ((handler (find-file-name-handler (expand-file-name file)
+                                           'insert-directory)))
+      (if handler
+          (funcall handler 'insert-directory file switches
+                   wildcard full-directory-p)
+        ;; Convert SWITCHES to a list of characters.
+        (setq switches (delete ?- (append switches nil)))
+        (if wildcard
+            (setq wildcard
+                  (if ls-lisp-support-shell-wildcards
+                      (wildcard-to-regexp (file-name-nondirectory file))
+                    (file-name-nondirectory file))
+                  file (file-name-directory file))
+          (if (memq ?B switches) (setq wildcard "[^~]\\'")))
+        (ls-lisp-insert-directory
+         file switches (ls-lisp-time-index switches)
+         wildcard full-directory-p)))))
+
+(defun ls-lisp-insert-directory
+  (file switches time-index wildcard full-directory-p)
   "Insert directory listing for FILE, formatted according to SWITCHES.
-Leaves point after the inserted text.
-Optional third arg WILDCARD means treat FILE as shell wildcard.
-Optional fourth arg FULL-DIRECTORY-P means file is a directory and
-switches do not contain `d', so that a full listing is expected.
-
-This version of the function comes from `ls-lisp.el'.  It does not
-run any external programs or shells.  It supports ordinary shell
-wildcards if `ls-lisp-support-shell-wildcards' variable is non-nil;
-otherwise, it interprets wildcards as regular expressions to match
-file names.
-
-Not all `ls' switches are supported.  The switches that work
-are: A a c i r S s t u"
-  (let ((handler (find-file-name-handler file 'insert-directory))
-        fattr)
-    (if handler
-        (funcall handler 'insert-directory file switches
-                 wildcard full-directory-p)
-      ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
-      ;; `ls' don't mind, we certainly do, because it makes us think
-      ;; there is no wildcard, only a directory name.
-      (if (and ls-lisp-support-shell-wildcards
-               (string-match "[[?*]" file))
-          (progn
-            (or (not (eq (aref file (1- (length file))) ?/))
-                (setq file (substring file 0 (1- (length file)))))
-            (setq wildcard t)))
-      ;; Convert SWITCHES to a list of characters.
-      (setq switches (append switches nil))
-      (if wildcard
-          (setq wildcard
-                (if ls-lisp-support-shell-wildcards
-                    (wildcard-to-regexp (file-name-nondirectory file))
-                  (file-name-nondirectory file))
-                file (file-name-directory file)))
-      (if (or wildcard
-              full-directory-p)
-          (let* ((dir (file-name-as-directory file))
-                 (default-directory dir);; so that file-attributes works
-                 (sum 0)
-                 elt
-                 short
-                 (file-alist (directory-files-and-attributes dir nil wildcard))
-                 (now (current-time))
-                 ;; do all bindings here for speed
-                 file-size
-                 fil attr)
-            (cond ((memq ?A switches)
-                   (setq file-alist
-                         (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
-                  ((not (memq ?a switches))
-                   ;; if neither -A  nor -a, flush . files
-                   (setq file-alist
-                         (ls-lisp-delete-matching "^\\." file-alist))))
-            ;; ``Total'' line (filled in afterwards).
-            (insert (if (car-safe file-alist)
-                        "total \007\n"
-                      ;; Shell says ``No match'' if no files match
-                      ;; the wildcard; let's say something similar.
-                      "(No match)\ntotal \007\n"))
-            (setq file-alist
-                  (ls-lisp-handle-switches file-alist switches))
+Leaves point after the inserted text.  This is an internal function
+optionally called by the `ls-lisp.el' version of `insert-directory'.
+It is called recursively if the -R switch is used.
+SWITCHES is a *list* of characters.  TIME-INDEX is the time index into
+file-attributes according to SWITCHES.  WILDCARD is nil or an *Emacs
+regexp*.  FULL-DIRECTORY-P means file is a directory and SWITCHES does
+not contain `d', so that a full listing is expected."
+  ;; Sometimes we get ".../foo*/" as FILE.  While the shell and
+  ;; `ls' don't mind, we certainly do, because it makes us think
+  ;; there is no wildcard, only a directory name.
+  (if (and ls-lisp-support-shell-wildcards
+           (string-match "[[?*]" file))
+      (progn
+        (or (not (eq (aref file (1- (length file))) ?/))
+            (setq file (substring file 0 (1- (length file)))))
+        (setq wildcard t)))
+  (if (or wildcard full-directory-p)
+      (let* ((dir (file-name-as-directory file))
+             (default-directory dir)    ; so that file-attributes works
+             (file-alist
+              (directory-files-and-attributes dir nil wildcard t))
+             (now (current-time))
+             (sum 0)
+             ;; do all bindings here for speed
+             total-line files elt short file-size fil attr)
+        (cond ((memq ?A switches)
+               (setq file-alist
+                     (ls-lisp-delete-matching "^\\.\\.?$" file-alist)))
+              ((not (memq ?a switches))
+               ;; if neither -A  nor -a, flush . files
+               (setq file-alist
+                     (ls-lisp-delete-matching "^\\." file-alist))))
+        (setq file-alist
+              (ls-lisp-handle-switches file-alist switches))
+        (if (memq ?C switches)          ; column (-C) format
+            (ls-lisp-column-format file-alist)
+          (setq total-line (cons (point) (car-safe file-alist)))
+          (setq files file-alist)
+          (while files                  ; long (-l) format
+            (setq elt (car files)
+                  files (cdr files)
+                  short (car elt)
+                  attr (cdr elt)
+                  file-size (nth 7 attr))
+            (and attr
+                 (setq sum (+ file-size
+                              ;; Even if neither SUM nor file's size
+                              ;; overflow, their sum could.
+                              (if (or (< sum (- 134217727 file-size))
+                                      (floatp sum)
+                                      (floatp file-size))
+                                  sum
+                                (float sum))))
+                 (insert (ls-lisp-format short attr file-size
+                                         switches time-index now))))
+          ;; Insert total size of all files:
+          (save-excursion
+            (goto-char (car total-line))
+            (or (cdr total-line)
+                ;; Shell says ``No match'' if no files match
+                ;; the wildcard; let's say something similar.
+                (insert "(No match)\n"))
+            (insert (format "total %.0f\n" (fceiling (/ sum 1024.0))))))
+        (if (memq ?R switches)
+            ;; List the contents of all directories recursively.
+            ;; cadr of each element of `file-alist' is t for
+            ;; directory, string (name linked to) for symbolic
+            ;; link, or nil.
             (while file-alist
               (setq elt (car file-alist)
-                    file-alist (cdr file-alist)
-                    short (car elt)
-                    attr (cdr elt)
-                    file-size (nth 7 attr))
-              (and attr
-                   (setq sum
-                         ;; Even if neither SUM nor file's size
-                         ;; overflow, their sum could.
-                         (if (or (< sum (- 134217727 file-size))
-                                 (floatp sum)
-                                 (floatp file-size))
-                             (+ sum file-size)
-                           (+ (float sum) file-size)))
-                   (insert (ls-lisp-format short attr file-size switches now))
-                   ))
-            ;; Fill in total size of all files:
-            (save-excursion
-              (search-backward "total \007")
-              (goto-char (match-end 0))
-              (delete-char -1)
-              (insert (format "%.0f" (fceiling (/ sum 1024.0))))))
-        ;; if not full-directory-p, FILE *must not* end in /, as
-        ;; file-attributes will not recognize a symlink to a directory
-        ;; must make it a relative filename as ls does:
-        (if (eq (aref file (1- (length file))) ?/)
-            (setq file (substring file 0 (1- (length file)))))
-        (setq fattr (file-attributes file))
-        (if fattr
-            (insert (ls-lisp-format file fattr (nth 7 fattr)
-                                    switches (current-time)))
-          (message "%s: doesn't exist or is inaccessible" file)
-          (ding)
-          (sit-for 2))))))
+                    file-alist (cdr file-alist))
+              (when (and (eq (cadr elt) t) ; directory
+                         (not (string-match "\\`\\.\\.?\\'" (car elt))))
+                (setq elt (expand-file-name (car elt) dir))
+                (insert "\n" elt ":\n")
+                (ls-lisp-insert-directory
+                 elt switches time-index wildcard full-directory-p)))))
+    ;; If not full-directory-p, FILE *must not* end in /, as
+    ;; file-attributes will not recognize a symlink to a directory,
+    ;; so must make it a relative filename as ls does:
+    (if (eq (aref file (1- (length file))) ?/)
+        (setq file (substring file 0 -1)))
+    (let ((fattr (file-attributes file)))
+      (if fattr
+          (insert (ls-lisp-format file fattr (nth 7 fattr)
+                                  switches time-index (current-time)))
+        (message "%s: doesn't exist or is inaccessible" file)
+        (ding) (sit-for 2)))))          ; to show user the message!
+
+(defun ls-lisp-column-format (file-alist)
+  "Insert the file names (only) in FILE-ALIST into the current buffer.
+Format in columns, sorted vertically, following GNU ls -C.
+Responds to the window width as ls should but may not!"
+  (let (files fmt ncols collen (nfiles 0) (colwid 0))
+    ;; Count number of files as `nfiles', build list of filenames as
+    ;; `files', and find maximum filename length as `colwid':
+    (let (file len)
+      (while file-alist
+        (setq nfiles (1+ nfiles)
+              file (caar file-alist)
+              files (cons file files)
+              file-alist (cdr file-alist)
+              len (length file))
+        (if (> len colwid) (setq colwid len))))
+    (setq files (nreverse files)
+          colwid (+ 2 colwid)           ; 2 character column gap
+          fmt (format "%%-%ds" colwid)  ; print format
+          ncols (/ (window-width) colwid) ; no of columns
+          collen (/ nfiles ncols))      ; floor of column length
+    (if (> nfiles (* collen ncols)) (setq collen (1+ collen)))
+    ;; Output the file names in columns, sorted vertically:
+    (let ((i 0) j)
+      (while (< i collen)
+        (setq j i)
+        (while (< j nfiles)
+          (insert (format fmt (nth j files)))
+          (setq j (+ j collen)))
+        ;; FJW: This is completely unnecessary, but I don't like
+        ;; trailing white space...
+        (delete-region (point) (progn (skip-chars-backward " \t") (point)))
+        (insert ?\n)
+        (setq i (1+ i))))))
 
 (defun ls-lisp-delete-matching (regexp list)
-  ;; Delete all elements matching REGEXP from LIST, return new list.
+  "Delete all elements matching REGEXP from LIST, return new list."
   ;; Should perhaps use setcdr for efficiency.
   (let (result)
     (while list
-      (or (string-match regexp (car (car list)))
+      (or (string-match regexp (caar list))
           (setq result (cons (car list) result)))
       (setq list (cdr list)))
     result))
 
+(defsubst ls-lisp-string-lessp (s1 s2)
+  "Return t if string S1 is less than string S2 in lexicographic order.
+Case is significant if `ls-lisp-ignore-case' is nil.
+Unibyte strings are converted to multibyte for comparison."
+  (let ((u (compare-strings s1 0 nil s2 0 nil ls-lisp-ignore-case)))
+    (and (numberp u) (< u 0))))
+
 (defun ls-lisp-handle-switches (file-alist switches)
+  "Return new FILE-ALIST sorted according to SWITCHES.
+SWITCHES is a list of characters.  Default sorting is alphabetic."
   ;; FILE-ALIST's elements are (FILE . FILE-ATTRIBUTES).
-  ;; Return new alist sorted according to SWITCHES which is a list of
-  ;; characters.  Default sorting is alphabetically.
-  (let (index)
-    (setq file-alist
-          (sort file-alist
-                (cond ((memq ?S switches) ; sorted on size
-                       (function
-                        (lambda (x y)
-                          ;; 7th file attribute is file size
-                          ;; Make largest file come first
-                          (< (nth 7 (cdr y))
-                             (nth 7 (cdr x))))))
-                      ((memq ?t switches) ; sorted on time
-                       (setq index (ls-lisp-time-index switches))
-                       (function
-                        (lambda (x y)
-                          (ls-lisp-time-lessp (nth index (cdr y))
-                                              (nth index (cdr x))))))
-                      (t                ; sorted alphabetically
-                       (if ls-lisp-dired-ignore-case
-                           (function
-                            (lambda (x y)
-                              (string-lessp (upcase (car x))
-                                            (upcase (car y)))))
-                         (function
-                          (lambda (x y)
-                            (string-lessp (car x)
-                                          (car y))))))))))
-  (if (memq ?r switches)                ; reverse sort order
-      (setq file-alist (nreverse file-alist)))
-  file-alist)
+  (or (memq ?U switches)                ; unsorted
+      ;; Catch and ignore unexpected sorting errors
+      (condition-case err
+          (setq file-alist
+                (let (index)
+                  ;; Copy file-alist in case of error
+                  (sort (copy-sequence file-alist) ; modifies its argument!
+                        (cond ((memq ?S switches)
+                               (lambda (x y) ; sorted on size
+                                 ;; 7th file attribute is file size
+                                 ;; Make largest file come first
+                                 (< (nth 7 (cdr y))
+                                    (nth 7 (cdr x)))))
+                              ((setq index (ls-lisp-time-index switches))
+                               (lambda (x y) ; sorted on time
+                                 (ls-lisp-time-lessp (nth index (cdr y))
+                                                     (nth index (cdr x)))))
+                              ((memq ?X switches)
+                               (lambda (x y) ; sorted on extension
+                                 (ls-lisp-string-lessp
+                                  (ls-lisp-extension (car x))
+                                  (ls-lisp-extension (car y)))))
+                              (t
+                               (lambda (x y) ; sorted alphabetically
+                                 (ls-lisp-string-lessp (car x) (car y))))))))
+        (error (message "Unsorted (ls-lisp sorting error) - %s"
+                        (error-message-string err))
+               (ding) (sit-for 2))))    ; to show user the message!
+  (if (memq ?F switches)                ; classify switch
+      (setq file-alist (mapcar 'ls-lisp-classify file-alist)))
+  (if ls-lisp-dirs-first
+  ;; Re-sort directories first, without otherwise changing the
+  ;; ordering, and reverse whole list.  cadr of each element of
+  ;; `file-alist' is t for directory, string (name linked to) for
+  ;; symbolic link, or nil.
+      (let (el dirs files)
+        (while file-alist
+          (if (eq (cadr (setq el (car file-alist))) t) ; directory
+              (setq dirs (cons el dirs))
+            (setq files (cons el files)))
+          (setq file-alist (cdr file-alist)))
+        (setq file-alist
+              (if (memq ?U switches)    ; unsorted order is reversed
+                  (nconc dirs files)
+                (nconc files dirs)
+                ))))
+  ;; Finally reverse file alist if necessary.
+  ;; (eq below MUST compare `(not (memq ...))' to force comparison of
+  ;; `t' or `nil', rather than list tails!)
+  (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
+              (not (memq ?r switches))) ; reversed sort order requested
+          ls-lisp-dirs-first)           ; already reversed
+      (nreverse file-alist)
+    file-alist))
+
+(defun ls-lisp-classify (filedata)
+  "Append a character to each file name indicating the file type.
+Also, for regular files that are executable, append `*'.
+The file type indicators are `/' for directories, `@' for symbolic
+links, `|' for FIFOs, `=' for sockets, and nothing for regular files.
+\[But FIFOs and sockets are not recognised.]
+FILEDATA has the form (filename . `file-attributes').  Its `cadr' is t
+for directory, string (name linked to) for symbolic link, or nil."
+  (let ((dir (cadr filedata)) (file-name (car filedata)))
+    (cond ((or dir
+               ;; Parsing .lnk files here is perhaps overkill!
+               (setq dir (ls-lisp-parse-symlink file-name)))
+           (cons
+            (concat file-name (if (eq dir t) "/" "@"))
+            (cdr filedata)))
+          ((string-match "x" (nth 9 filedata))
+           (cons
+            (concat file-name "*")
+            (cdr filedata)))
+          (t filedata))))
+
+(defun ls-lisp-extension (filename)
+  "Return extension of FILENAME (ignoring any version extension)
+FOLLOWED by null and full filename, SOLELY for full alpha sort."
+  ;; Force extension sort order: `no ext' then `null ext' then `ext'
+  ;; to agree with GNU ls.
+  (concat
+   (let* ((i (length filename)) end)
+     (if (= (aref filename (1- i)) ?.) ; null extension
+         "\0"
+       (while (and (>= (setq i (1- i)) 0)
+                   (/= (aref filename i) ?.)))
+       (if (< i 0) "\0\0"               ; no extension
+         (if (/= (aref filename (1+ i)) ?~)
+             (substring filename (1+ i))
+           ;; version extension found -- ignore it
+           (setq end i)
+           (while (and (>= (setq i (1- i)) 0)
+                       (/= (aref filename i) ?.)))
+           (if (< i 0) "\0\0"   ; no extension
+             (substring filename (1+ i) end))))
+       )) "\0" filename))
 
 ;; From Roland McGrath.  Can use this to sort on time.
 (defun ls-lisp-time-lessp (time0 time1)
-  (let ((hi0 (car time0))
-        (hi1 (car time1))
-        (lo0 (car (cdr time0)))
-        (lo1 (car (cdr time1))))
+  "Return t if time TIME0 is earlier than time TIME1."
+  (let ((hi0 (car time0)) (hi1 (car time1)))
     (or (< hi0 hi1)
         (and (= hi0 hi1)
-             (< lo0 lo1)))))
-
-
-(defun ls-lisp-format (file-name file-attr file-size switches now)
-  (let ((file-type (nth 0 file-attr)))
+             (< (cadr time0) (cadr time1))))))
+
+(defun ls-lisp-format (file-name file-attr file-size switches time-index now)
+  "Format one line of long ls output for file FILE-NAME.
+FILE-ATTR and FILE-SIZE give the file's attributes and size.
+SWITCHES, TIME-INDEX and NOW give the full switch list and time data."
+  (let ((file-type (nth 0 file-attr))
+        ;; t for directory, string (name linked to)
+        ;; for symbolic link, or nil.
+        (drwxrwxrwx (nth 8 file-attr))) ; attribute string ("drwxrwxrwx")
+    (and (null file-type)
+         ;; Maybe no kernel support for symlinks, so...
+         (setq file-type (ls-lisp-parse-symlink file-name))
+         (aset drwxrwxrwx 0 ?l)) ; symbolic link - update attribute string
     (concat (if (memq ?i switches)      ; inode number
-                (format "%6d " (nth 10 file-attr)))
+                (format " %6d" (nth 10 file-attr)))
             ;; nil is treated like "" in concat
             (if (memq ?s switches)      ; size in K
-                (format "%4.0f " (fceiling (/ file-size 1024.0))))
-            (nth 8 file-attr)           ; permission bits
-            ;; numeric uid/gid are more confusing than helpful
+                (format " %4.0f" (fceiling (/ file-size 1024.0))))
+            drwxrwxrwx                  ; attribute string
+            (if (memq 'links ls-lisp-verbosity)
+                (format " %3d" (nth 1 file-attr))) ; link count
+            ;; Numeric uid/gid are more confusing than helpful;
             ;; Emacs should be able to make strings of them.
-            ;; user-login-name and user-full-name could take an
-            ;; optional arg.
-            (format (if (floatp file-size)
-                        " %3d %-8s %-8s %8.0f "
-                      " %3d %-8s %-8s %8d ")
-                    (nth 1 file-attr)   ; no. of links
-                    (if (= (user-uid) (nth 2 file-attr))
-                        (user-login-name)
-                      (int-to-string (nth 2 file-attr)))        ; uid
-                    (if (eq system-type 'ms-dos)
-                        "root"          ; everything is root on MSDOS.
-                      (int-to-string (nth 3 file-attr)))        ; gid
-                    file-size
-                    )
-            (ls-lisp-format-time file-attr switches now)
+            ;; They tend to be bogus on non-UNIX platforms anyway so
+            ;; optionally hide them.
+            (if (memq 'uid ls-lisp-verbosity)
+                ;; (user-login-name uid) works on Windows NT but not
+                ;; on 9x and maybe not on some other platforms, so...
+                (let ((uid (nth 2 file-attr)))
+                  (if (= uid (user-uid))
+                      (format " %-8s" (user-login-name))
+                    (format " %-8d" uid))))
+            (if (not (memq ?G switches)) ; GNU ls -- shows group by default
+                (if (or (memq ?g switches) ; UNIX ls -- no group by default
+                        (memq 'gid ls-lisp-verbosity))
+                    (if (memq system-type '(macos windows-nt ms-dos))
+                        ;; No useful concept of group...
+                        "root"
+                      (let* ((gid (nth 3 file-attr))
+                             (group (user-login-name gid)))
+                        (if group
+                            (format " %-8s" group)
+                          (format " %-8d" gid))))))
+            (format (if (floatp file-size) " %8.0f" " %8d") file-size)
+            " "
+            (ls-lisp-format-time file-attr time-index now)
             " "
             file-name
             (if (stringp file-type)     ; is a symbolic link
-                (concat " -> " file-type)
-              "")
+                (concat " -> " file-type))
             "\n"
             )))
 
 (defun ls-lisp-time-index (switches)
-  ;; Return index into file-attributes according to ls SWITCHES.
-  (cond
-   ((memq ?c switches) 6)               ; last mode change
-   ((memq ?u switches) 4)               ; last access
-   ;; default is last modtime
-   (t 5)))
-
-(defun ls-lisp-format-time (file-attr switches now)
-  ;; Format time string for file with attributes FILE-ATTR according
-  ;; to SWITCHES (a list of ls option letters of which c and u are recognized).
-  ;; Use the same method as `ls' to decide whether to show time-of-day or year,
-  ;; depending on distance between file date and NOW.
-  (let* ((time (nth (ls-lisp-time-index switches) file-attr))
+  "Return time index into file-attributes according to ls SWITCHES list.
+Return nil if no time switch found."
+  ;; FJW: Default of nil is IMPORTANT and used in `ls-lisp-handle-switches'!
+  (cond ((memq ?c switches) 6)          ; last mode change
+        ((memq ?t switches) 5)          ; last modtime
+        ((memq ?u switches) 4)))        ; last access
+
+(defun ls-lisp-format-time (file-attr time-index now)
+  "Format time for file with attributes FILE-ATTR according to TIME-INDEX.
+Use the same method as ls to decide whether to show time-of-day or year,
+depending on distance between file date and NOW.
+All ls time options, namely c, t and u, are handled."
+  (let* ((time (nth (or time-index 5) file-attr)) ; default is last modtime
          (diff16 (- (car time) (car now)))
          (diff (+ (ash diff16 16) (- (car (cdr time)) (car (cdr now)))))
          (past-cutoff (- (* 6 30 24 60 60)))    ; 6 30-day months