Initial revision

lisp/ls-lisp.el

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+;;;; dired-lisp.el - emulate ls completely in Emacs Lisp
+;;;; Copyright (C) 1990 Sebastian Kremer
+
+;;;; Useful if you cannot afford to fork Emacs on a real memory UNIX,
+;;;; under VMS, or if you don't have the ls program.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 1, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;;; WARNING:
+
+;;;; I initially used file-name-all-completions instead of
+;;;; directory-files and got an internal Emacs error:
+
+;;;;   Signalling: (wrong-type-argument natnump #<EMACS BUG: ILLEGAL
+;;;;   DATATYPE (#o37777777727) Save your buffers immediately and please
+;;;;   report this bug>)
+
+;;;; It has never happened again and had no bad aftereffects, but do be
+;;;; careful!
+
+;;;  RESTRICTIONS:
+;;;; Always sorts by name (ls switches are completely ignored for now)
+;;;; Cannot display date of file, displays a fake date "Jan 00 00:00" instead
+;;;; Only numeric uid/gid
+
+;;;; It is surprisingly fast, though!
+
+;;;; TODO:
+;;;; Recognize at least some ls switches: l R g F i
+
+(require 'dired)
+
+(or (fboundp 'tree-dired-ls)		; save original function definition
+    (fset 'tree-dired-ls (symbol-function 'dired-ls)))
+
+;; perhaps buffer-local (he he)
+(defvar dired-ls-function 'dired-lisp-ls
+  "*Function dired uses to obtain ls output.
+Possible values 'tree-dired-ls and 'dired-lisp-ls.
+Arglist is (FILE &optional SWITCHES WILDCARD FULL-DIRECTORY-P).")
+
+(defun dired-ls (file &optional switches wildcard full-directory-p)
+  (funcall dired-ls-function file switches wildcard full-directory-p))
+
+(defun dired-lisp-ls (file &optional switches wildcard full-directory-p)
+;  "Insert ls output of FILE, optionally formatted with SWITCHES.
+;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'.
+;
+;SWITCHES default to dired-listing-switches."
+  (or switches (setq switches dired-listing-switches))
+  (if wildcard
+      (error "Cannot handle wildcards in lisp emulation of `ls'."))
+  (if full-directory-p
+      (let* ((dir (file-name-as-directory file))
+	     (start (length dir))
+	     (sum 0))
+	(insert "total \007\n")		; fill in afterwards
+	(insert
+	 (mapconcat 
+	  (function (lambda (short)
+		      (let* ((fil (concat dir short))
+			     (attr (file-attributes fil))
+			     (size (nth 7 attr)))
+			;;(debug)
+			(setq sum (+ sum size))
+			(dired-lisp-format
+			 ;;(file-name-nondirectory fil)
+			 ;;(dired-make-relative fil dir)
+			 ;;(substring fil start)
+			 short
+			 attr
+			 switches))))
+	  (directory-files dir)
+	  ""))
+	(save-excursion
+	  (search-backward "total \007")
+	  (goto-char (match-end 0))
+	  (delete-char -1)
+	  (insert (format "%d" sum)))
+	)
+    ;; 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:
+    (setq file (file-name-nondirectory file))
+    (insert (dired-lisp-format file (file-attributes file) switches)))
+  )
+
+(defun dired-lisp-format (file-name file-attr &optional switches)
+  (let ((file-type (nth 0 file-attr)))
+    (concat (nth 8 file-attr)		; permission bits
+	    " "
+	    (dired-lisp-pad (nth 1 file-attr) -3) ; no. of links
+	    ;; numeric uid/gid are more confusing than helpful
+	    ;; Emacs should be able to make strings of them
+	    " " (dired-lisp-pad (nth 2 file-attr) -6)		; uid
+	    " " (dired-lisp-pad (nth 3 file-attr) -6)		; gid
+	    " "
+	    (dired-lisp-pad (nth 7 file-attr) -8) ; size in bytes
+	    ;; file-attributes's time is in a braindead format
+	    ;; Emacs should have a ctime function
+	    " " "Jan 00 00:00 "		; fake time
+	    file-name
+	    (if (stringp file-type)	; is a symbolic link
+		(concat " -> " file-type)
+	      "")
+	    "\n"
+	    )))
+
+;; format should really do anything printf can!!
+(defun dired-lisp-pad (arg width &optional pad-char)
+  "Pad ARG to WIDTH, from left if WIDTH < 0.
+Non-nil third arg optional PAD-CHAR defaults to a space."
+  (or pad-char (setq pad-char ?\040))
+  (if (integerp arg)
+      (setq arg (int-to-string arg)))
+  (let (l pad reverse)
+    (if (< width 0)
+	(setq reverse t
+	      width (- width)))
+    (setq l (length arg)
+	  pad (- width l))
+    (if (> pad 0)
+	(if reverse
+	    (concat (make-string pad pad-char) arg)
+	  (concat arg (make-string pad pad-char)))
+      arg)))