lisp/hexl.el

   1 ;;; hexl.el --- edit a file in a hex dump format using the hexl filter -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1989, 1994, 1998, 2001-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: Keith Gabryelski <ag@wheaties.ai.mit.edu>
   6 ;; Maintainer: FSF
   7 ;; Keywords: data
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This package implements a major mode for editing binary files.  It uses
  27 ;; a program called hexl, supplied with the GNU Emacs distribution, that
  28 ;; can filter a binary into an editable format or from the format back into
  29 ;; binary.  For full instructions, invoke `hexl-mode' on an empty buffer and
  30 ;; do M-x `describe-mode'.
  31 ;;
  32 ;; NOTE: Remember to change `hexl-program' or `hexl-options' if needed.
  33 ;;
  34 ;; Currently hexl only supports big endian hex output with 16 bit
  35 ;; grouping.
  36 ;;
  37 ;; -iso in `hexl-options' will allow iso characters to display in the
  38 ;; ASCII region of the screen (if your Emacs supports this) instead of
  39 ;; changing them to dots.
  40
  41 ;;; Code:
  42
  43 (require 'eldoc)
  44 (eval-when-compile (require 'cl))       ;For letf (default-value 'major-mode).
  45
  46 ;;
  47 ;; vars here
  48 ;;
  49
  50 (defgroup hexl nil
  51   "Edit a file in a hex dump format using the hexl filter."
  52   :group 'data)
  53
  54 (defcustom hexl-bits 16
  55   "The bit grouping that hexl will use."
  56   :type '(choice (const 8 )
  57                  (const 16)
  58                  (const 32)
  59                  (const 64))
  60   :group 'hexl
  61   :version "24.2")
  62
  63 (defcustom hexl-program "hexl"
  64   "The program that will hexlify and dehexlify its stdin.
  65 `hexl-program' will always be concatenated with `hexl-options'
  66 and \"-de\" when dehexlifying a buffer."
  67   :type 'string
  68   :group 'hexl)
  69
  70 (defcustom hexl-iso ""
  71   "If your Emacs can handle ISO characters, this should be set to
  72 \"-iso\" otherwise it should be \"\"."
  73   :type 'string
  74   :group 'hexl)
  75
  76 (defcustom hexl-options (format "-hex %s" hexl-iso)
  77   "Space separated options to `hexl-program' that suit your needs.
  78 Quoting cannot be used, so the arguments cannot themselves contain spaces.
  79 If you wish to set the `-group-by-X-bits' options, set `hexl-bits' instead,
  80 as that will override any bit grouping options set here."
  81   :type 'string
  82   :group 'hexl)
  83
  84 (defcustom hexl-follow-ascii t
  85   "If non-nil then highlight the ASCII character corresponding to point."
  86   :type 'boolean
  87   :group 'hexl
  88   :version "20.3")
  89
  90 (defcustom hexl-mode-hook '(hexl-follow-line hexl-activate-ruler)
  91   "Normal hook run when entering Hexl mode."
  92   :type 'hook
  93   :options '(hexl-follow-line hexl-activate-ruler turn-on-eldoc-mode)
  94   :group 'hexl)
  95
  96 (defface hexl-address-region
  97   '((t (:inherit header-line)))
  98   "Face used in address area of hexl-mode buffer."
  99   :group 'hexl)
 100
 101 (defface hexl-ascii-region
 102   '((t (:inherit header-line)))
 103   "Face used in ascii area of hexl-mode buffer."
 104   :group 'hexl)
 105
 106 (defvar hexl-max-address 0
 107   "Maximum offset into hexl buffer.")
 108
 109 (defvar hexl-mode-map
 110   (let ((map (make-keymap)))
 111     ;; Make all self-inserting keys go through hexl-self-insert-command,
 112     ;; because we need to convert them to unibyte characters before
 113     ;; inserting them into the buffer.
 114     (define-key map [remap self-insert-command] 'hexl-self-insert-command)
 115
 116     (define-key map "\C-m" 'hexl-self-insert-command)
 117     (define-key map [left] 'hexl-backward-char)
 118     (define-key map [right] 'hexl-forward-char)
 119     (define-key map [up] 'hexl-previous-line)
 120     (define-key map [down] 'hexl-next-line)
 121     (define-key map [M-left] 'hexl-backward-short)
 122     (define-key map [?\e left] 'hexl-backward-short)
 123     (define-key map [M-right] 'hexl-forward-short)
 124     (define-key map [?\e right] 'hexl-forward-short)
 125     (define-key map [next] 'hexl-scroll-up)
 126     (define-key map [prior] 'hexl-scroll-down)
 127     (define-key map [home] 'hexl-beginning-of-line)
 128     (define-key map [end] 'hexl-end-of-line)
 129     (define-key map [C-home] 'hexl-beginning-of-buffer)
 130     (define-key map [C-end] 'hexl-end-of-buffer)
 131     (define-key map [deletechar] 'undefined)
 132     (define-key map [deleteline] 'undefined)
 133     (define-key map [insertline] 'undefined)
 134     (define-key map [S-delete] 'undefined)
 135     (define-key map "\177" 'undefined)
 136
 137     (define-key map "\C-a" 'hexl-beginning-of-line)
 138     (define-key map "\C-b" 'hexl-backward-char)
 139     (define-key map "\C-d" 'undefined)
 140     (define-key map "\C-e" 'hexl-end-of-line)
 141     (define-key map "\C-f" 'hexl-forward-char)
 142
 143     (if (not (memq (key-binding (char-to-string help-char))
 144                    '(help-command ehelp-command)))
 145         (define-key map (char-to-string help-char) 'undefined))
 146
 147     (define-key map "\C-k" 'undefined)
 148     (define-key map "\C-n" 'hexl-next-line)
 149     (define-key map "\C-o" 'undefined)
 150     (define-key map "\C-p" 'hexl-previous-line)
 151     (define-key map "\C-q" 'hexl-quoted-insert)
 152     (define-key map "\C-t" 'undefined)
 153     (define-key map "\C-v" 'hexl-scroll-up)
 154     (define-key map "\C-w" 'undefined)
 155     (define-key map "\C-y" 'undefined)
 156
 157     (fset 'hexl-ESC-prefix (copy-keymap 'ESC-prefix))
 158     (define-key map "\e" 'hexl-ESC-prefix)
 159     (define-key map "\e\C-a" 'hexl-beginning-of-512b-page)
 160     (define-key map "\e\C-b" 'hexl-backward-short)
 161     (define-key map "\e\C-d" 'hexl-insert-decimal-char)
 162     (define-key map "\e\C-e" 'hexl-end-of-512b-page)
 163     (define-key map "\e\C-f" 'hexl-forward-short)
 164     (define-key map "\e\C-i" 'undefined)
 165     (define-key map "\e\C-j" 'undefined)
 166     (define-key map "\e\C-k" 'undefined)
 167     (define-key map "\e\C-o" 'hexl-insert-octal-char)
 168     (define-key map "\e\C-q" 'undefined)
 169     (define-key map "\e\C-t" 'undefined)
 170     (define-key map "\e\C-x" 'hexl-insert-hex-char)
 171     (define-key map "\eb" 'hexl-backward-word)
 172     (define-key map "\ec" 'undefined)
 173     (define-key map "\ed" 'undefined)
 174     (define-key map "\ef" 'hexl-forward-word)
 175     (define-key map "\eg" 'hexl-goto-hex-address)
 176     (define-key map "\ei" 'undefined)
 177     (define-key map "\ej" 'hexl-goto-address)
 178     (define-key map "\ek" 'undefined)
 179     (define-key map "\el" 'undefined)
 180     (define-key map "\eq" 'undefined)
 181     (define-key map "\es" 'undefined)
 182     (define-key map "\et" 'undefined)
 183     (define-key map "\eu" 'undefined)
 184     (define-key map "\ev" 'hexl-scroll-down)
 185     (define-key map "\ey" 'undefined)
 186     (define-key map "\ez" 'undefined)
 187     (define-key map "\e<" 'hexl-beginning-of-buffer)
 188     (define-key map "\e>" 'hexl-end-of-buffer)
 189
 190     (fset 'hexl-C-c-prefix (copy-keymap mode-specific-map))
 191     (define-key map "\C-c" 'hexl-C-c-prefix)
 192     (define-key map "\C-c\C-c" 'hexl-mode-exit)
 193
 194     (fset 'hexl-C-x-prefix (copy-keymap 'Control-X-prefix))
 195     (define-key map "\C-x" 'hexl-C-x-prefix)
 196     (define-key map "\C-x[" 'hexl-beginning-of-1k-page)
 197     (define-key map "\C-x]" 'hexl-end-of-1k-page)
 198     (define-key map "\C-x\C-p" 'undefined)
 199     (define-key map "\C-x\C-s" 'hexl-save-buffer)
 200     (define-key map "\C-x\C-t" 'undefined)
 201     map))
 202
 203 ;; Variable declarations for suppressing warnings from the byte-compiler.
 204 (defvar ruler-mode)
 205 (defvar ruler-mode-ruler-function)
 206 (defvar hl-line-mode)
 207 (defvar hl-line-range-function)
 208 (defvar hl-line-face)
 209
 210 ;; Variables where the original values are stored to.
 211 (defvar hexl-mode--old-var-vals ())
 212 (make-variable-buffer-local 'hexl-mode--old-var-vals)
 213
 214 (defvar hexl-ascii-overlay nil
 215   "Overlay used to highlight ASCII element corresponding to current point.")
 216 (make-variable-buffer-local 'hexl-ascii-overlay)
 217
 218 (defvar hexl-font-lock-keywords
 219   '(("^\\([0-9a-f]+:\\).\\{40\\}  \\(.+$\\)"
 220      ;; "^\\([0-9a-f]+:\\).+  \\(.+$\\)"
 221      (1 'hexl-address-region t t)
 222      (2 'hexl-ascii-region t t)))
 223   "Font lock keywords used in `hexl-mode'.")
 224
 225 (defun hexl-rulerize (string bits)
 226   (let ((size (/ bits 4)) (strlen (length string)) (pos 0) (ruler ""))
 227     (while (< pos strlen)
 228       (setq ruler (concat ruler " " (substring string pos (+ pos size))))
 229       (setq pos (+ pos size)))
 230     (substring ruler 1) ))
 231
 232 (defvar hexl-rulers
 233   (mapcar
 234    (lambda (bits)
 235      (cons bits
 236            (concat " 87654321  "
 237                    (hexl-rulerize "00112233445566778899aabbccddeeff" bits)
 238                    "  0123456789abcdef")))
 239    '(8 16 32 64)))
 240 ;; routines
 241
 242 (put 'hexl-mode 'mode-class 'special)
 243
 244 ;; 10 chars for the "address: "
 245 ;; 32 chars for the hexlified bytes
 246 ;; 1 char for the space
 247 ;; 16 chars for the character display
 248 ;; X chars for the spaces (128 bits divided by the hexl-bits)
 249 ;; 1 char for the newline.
 250 (defun hexl-line-displen ()
 251   "The length of a hexl display line (varies with `hexl-bits')."
 252   (+ 60 (/ 128 (or hexl-bits 16))))
 253
 254 (defun hexl-mode--minor-mode-p (var)
 255   (memq var '(ruler-mode hl-line-mode)))
 256
 257 (defun hexl-mode--setq-local (var val)
 258   ;; `var' can be either a symbol or a pair, in which case the `car'
 259   ;; is the getter function and the `cdr' is the corresponding setter.
 260   (unless (or (member var hexl-mode--old-var-vals)
 261               (assoc var hexl-mode--old-var-vals))
 262     (push (if (or (consp var) (boundp var))
 263               (cons var
 264                     (if (consp var) (funcall (car var)) (symbol-value var)))
 265             var)
 266           hexl-mode--old-var-vals))
 267   (cond
 268    ((consp var) (funcall (cdr var) val))
 269    ((hexl-mode--minor-mode-p var) (funcall var (if val 1 -1)))
 270    (t (set (make-local-variable var) val))))
 271
 272 ;;;###autoload
 273 (defun hexl-mode (&optional arg)
 274   "\\<hexl-mode-map>A mode for editing binary files in hex dump format.
 275 This is not an ordinary major mode; it alters some aspects
 276 of the current mode's behavior, but not all; also, you can exit
 277 Hexl mode and return to the previous mode using `hexl-mode-exit'.
 278
 279 This function automatically converts a buffer into the hexl format
 280 using the function `hexlify-buffer'.
 281
 282 Each line in the buffer has an \"address\" (displayed in hexadecimal)
 283 representing the offset into the file that the characters on this line
 284 are at and 16 characters from the file (displayed as hexadecimal
 285 values grouped every `hexl-bits' bits) and as their ASCII values.
 286
 287 If any of the characters (displayed as ASCII characters) are
 288 unprintable (control or meta characters) they will be replaced as
 289 periods.
 290
 291 If `hexl-mode' is invoked with an argument the buffer is assumed to be
 292 in hexl format.
 293
 294 A sample format:
 295
 296   HEX ADDR: 0001 0203 0405 0607 0809 0a0b 0c0d 0e0f     ASCII-TEXT
 297   --------  ---- ---- ---- ---- ---- ---- ---- ----  ----------------
 298   00000000: 5468 6973 2069 7320 6865 786c 2d6d 6f64  This is hexl-mod
 299   00000010: 652e 2020 4561 6368 206c 696e 6520 7265  e.  Each line re
 300   00000020: 7072 6573 656e 7473 2031 3620 6279 7465  presents 16 byte
 301   00000030: 7320 6173 2068 6578 6164 6563 696d 616c  s as hexadecimal
 302   00000040: 2041 5343 4949 0a61 6e64 2070 7269 6e74   ASCII.and print
 303   00000050: 6162 6c65 2041 5343 4949 2063 6861 7261  able ASCII chara
 304   00000060: 6374 6572 732e 2020 416e 7920 636f 6e74  cters.  Any cont
 305   00000070: 726f 6c20 6f72 206e 6f6e 2d41 5343 4949  rol or non-ASCII
 306   00000080: 2063 6861 7261 6374 6572 730a 6172 6520   characters.are
 307   00000090: 6469 7370 6c61 7965 6420 6173 2070 6572  displayed as per
 308   000000a0: 696f 6473 2069 6e20 7468 6520 7072 696e  iods in the prin
 309   000000b0: 7461 626c 6520 6368 6172 6163 7465 7220  table character
 310   000000c0: 7265 6769 6f6e 2e0a                      region..
 311
 312 Movement is as simple as movement in a normal Emacs text buffer.  Most
 313 cursor movement bindings are the same (ie. Use \\[hexl-backward-char], \\[hexl-forward-char], \\[hexl-next-line], and \\[hexl-previous-line]
 314 to move the cursor left, right, down, and up).
 315
 316 Advanced cursor movement commands (ala \\[hexl-beginning-of-line], \\[hexl-end-of-line], \\[hexl-beginning-of-buffer], and \\[hexl-end-of-buffer]) are
 317 also supported.
 318
 319 There are several ways to change text in hexl mode:
 320
 321 ASCII characters (character between space (0x20) and tilde (0x7E)) are
 322 bound to self-insert so you can simply type the character and it will
 323 insert itself (actually overstrike) into the buffer.
 324
 325 \\[hexl-quoted-insert] followed by another keystroke allows you to insert the key even if
 326 it isn't bound to self-insert.  An octal number can be supplied in place
 327 of another key to insert the octal number's ASCII representation.
 328
 329 \\[hexl-insert-hex-char] will insert a given hexadecimal value (if it is between 0 and 0xFF)
 330 into the buffer at the current point.
 331
 332 \\[hexl-insert-octal-char] will insert a given octal value (if it is between 0 and 0377)
 333 into the buffer at the current point.
 334
 335 \\[hexl-insert-decimal-char] will insert a given decimal value (if it is between 0 and 255)
 336 into the buffer at the current point.
 337
 338 \\[hexl-mode-exit] will exit hexl-mode.
 339
 340 Note: saving the file with any of the usual Emacs commands
 341 will actually convert it back to binary format while saving.
 342
 343 You can use \\[hexl-find-file] to visit a file in Hexl mode.
 344
 345 \\[describe-bindings] for advanced commands."
 346   (interactive "p")
 347   (unless (eq major-mode 'hexl-mode)
 348     (let ((modified (buffer-modified-p))
 349           (inhibit-read-only t)
 350           (original-point (- (point) (point-min))))
 351       (and (eobp) (not (bobp))
 352            (setq original-point (1- original-point)))
 353       ;; If `hexl-mode' is invoked with an argument the buffer is assumed to
 354       ;; be in hexl format.
 355       (when (memq arg '(1 nil))
 356         ;; If the buffer's EOL type is -dos, we need to account for
 357         ;; extra CR characters added when hexlify-buffer writes the
 358         ;; buffer to a file.
 359         ;; FIXME: This doesn't take into account multibyte coding systems.
 360         (when (eq (coding-system-eol-type buffer-file-coding-system) 1)
 361           (setq original-point (+ (count-lines (point-min) (point))
 362                                   original-point))
 363           (or (bolp) (setq original-point (1- original-point))))
 364         (hexlify-buffer)
 365         (restore-buffer-modified-p modified))
 366       (set (make-local-variable 'hexl-max-address)
 367            (+ (* (/ (1- (buffer-size)) (hexl-line-displen)) 16) 15))
 368       (condition-case nil
 369           (hexl-goto-address original-point)
 370         (error nil)))
 371
 372     ;; We do not turn off the old major mode; instead we just
 373     ;; override most of it.  That way, we can restore it perfectly.
 374
 375     (hexl-mode--setq-local '(current-local-map . use-local-map) hexl-mode-map)
 376
 377     (hexl-mode--setq-local 'mode-name "Hexl")
 378     (hexl-mode--setq-local 'isearch-search-fun-function
 379                            'hexl-isearch-search-function)
 380     (hexl-mode--setq-local 'major-mode 'hexl-mode)
 381
 382     (hexl-mode--setq-local '(syntax-table . set-syntax-table)
 383                            (standard-syntax-table))
 384
 385     (add-hook 'write-contents-functions 'hexl-save-buffer nil t)
 386
 387     (hexl-mode--setq-local 'require-final-newline nil)
 388
 389
 390     (hexl-mode--setq-local 'font-lock-defaults '(hexl-font-lock-keywords t))
 391
 392     (hexl-mode--setq-local 'revert-buffer-function
 393                            #'hexl-revert-buffer-function)
 394     (add-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer nil t)
 395
 396     ;; Set a callback function for eldoc.
 397     (hexl-mode--setq-local 'eldoc-documentation-function
 398                            #'hexl-print-current-point-info)
 399     (eldoc-add-command-completions "hexl-")
 400     (eldoc-remove-command "hexl-save-buffer"
 401                           "hexl-current-address")
 402
 403     (if hexl-follow-ascii (hexl-follow-ascii 1)))
 404   (run-mode-hooks 'hexl-mode-hook))
 405
 406
 407 (defun hexl-isearch-search-function ()
 408   (if (and (not isearch-regexp) (not isearch-word))
 409       (lambda (string &optional bound noerror count)
 410         (funcall
 411          (if isearch-forward 're-search-forward 're-search-backward)
 412          (let ((textre
 413                 (if (> (length string) 80)
 414                     (regexp-quote string)
 415                   (mapconcat (lambda (c) (regexp-quote (string c))) string
 416                              "\\(?:\n\\(?:[:a-f0-9]+ \\)+ \\)?"))))
 417            (if (string-match "\\` ?\\([a-f0-9]+ \\)*[a-f0-9]+ ?\\'" string)
 418                (concat textre "\\|"
 419                        (mapconcat 'regexp-quote (split-string string " ")
 420                                   " \\(?: .+\n[a-f0-9]+: \\)?"))
 421              textre))
 422          bound noerror count))
 423     (isearch-search-fun-default)))
 424
 425 (defvar hexl-in-save-buffer nil)
 426
 427 (defun hexl-save-buffer ()
 428   "Save a hexl format buffer as binary in visited file if modified."
 429   (interactive)
 430   (if hexl-in-save-buffer nil
 431     (restore-buffer-modified-p
 432      (if (buffer-modified-p)
 433          (let ((buf (generate-new-buffer " hexl"))
 434                (name (buffer-name))
 435                (start (point-min))
 436                (end (point-max))
 437                modified)
 438            (with-current-buffer buf
 439              (insert-buffer-substring name start end)
 440              (set-buffer name)
 441              (dehexlify-buffer)
 442              ;; Prevent infinite recursion.
 443              (let ((hexl-in-save-buffer t))
 444                (save-buffer))
 445              (setq modified (buffer-modified-p))
 446              (delete-region (point-min) (point-max))
 447              (insert-buffer-substring buf start end)
 448              (kill-buffer buf)
 449              modified))
 450        (message "(No changes need to be saved)")
 451        nil))
 452     ;; Return t to indicate we have saved t
 453     t))
 454
 455 ;;;###autoload
 456 (defun hexl-find-file (filename)
 457   "Edit file FILENAME as a binary file in hex dump format.
 458 Switch to a buffer visiting file FILENAME, creating one if none exists,
 459 and edit the file in `hexl-mode'."
 460   (interactive
 461    (list
 462     (let ((completion-ignored-extensions nil))
 463       (read-file-name "Filename: " nil nil 'ret-must-match))))
 464   ;; Ignore the user's setting of default major-mode.
 465   (letf (((default-value 'major-mode) 'fundamental-mode))
 466     (find-file-literally filename))
 467   (if (not (eq major-mode 'hexl-mode))
 468       (hexl-mode)))
 469
 470 (defun hexl-revert-buffer-function (_ignore-auto _noconfirm)
 471   (let ((coding-system-for-read 'no-conversion)
 472         revert-buffer-function)
 473     ;; Call the original `revert-buffer' without code conversion; also
 474     ;; prevent it from changing the major mode to normal-mode, which
 475     ;; calls `set-auto-mode'.
 476     (revert-buffer nil nil t)
 477     ;; A couple of hacks are necessary here:
 478     ;; 1. change the major-mode to one other than hexl-mode since the
 479     ;; function `hexl-mode' does nothing if the current major-mode is
 480     ;; already hexl-mode.
 481     ;; 2. reset change-major-mode-hook in case that `hexl-mode'
 482     ;; previously added hexl-maybe-dehexlify-buffer to it.
 483     (remove-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer t)
 484     (setq major-mode 'fundamental-mode)
 485     (hexl-mode)))
 486
 487 (defun hexl-mode-exit (&optional arg)
 488   "Exit Hexl mode, returning to previous mode.
 489 With arg, don't unhexlify buffer."
 490   (interactive "p")
 491   (if (or (eq arg 1) (not arg))
 492       (let ((modified (buffer-modified-p))
 493             (inhibit-read-only t)
 494             (original-point (1+ (hexl-current-address))))
 495         (dehexlify-buffer)
 496         (remove-hook 'write-contents-functions 'hexl-save-buffer t)
 497         (restore-buffer-modified-p modified)
 498         (goto-char original-point)
 499         ;; Maybe adjust point for the removed CR characters.
 500         (when (eq (coding-system-eol-type buffer-file-coding-system) 1)
 501           (setq original-point (- original-point
 502                                   (count-lines (point-min) (point))))
 503           (or (bobp) (setq original-point (1+ original-point))))
 504         (goto-char original-point)))
 505
 506   (remove-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer t)
 507   (remove-hook 'post-command-hook 'hexl-follow-ascii-find t)
 508   (setq hexl-ascii-overlay nil)
 509
 510   (let ((mms ()))
 511     (dolist (varval hexl-mode--old-var-vals)
 512       (let* ((bound (consp varval))
 513              (var (if bound (car varval) varval))
 514              (val (cdr-safe varval)))
 515         (cond
 516          ((consp var) (funcall (cdr var) val))
 517          ((hexl-mode--minor-mode-p var) (push (cons var val) mms))
 518          (bound (set (make-local-variable var) val))
 519          (t (kill-local-variable var)))))
 520     (kill-local-variable 'hexl-mode--old-var-vals)
 521     ;; Enable/disable minor modes.  Do it after having reset the other vars,
 522     ;; since some of them may affect the minor modes.
 523     (dolist (mm mms)
 524       (funcall (car mm) (if (cdr mm) 1 -1))))
 525
 526   (force-mode-line-update))
 527
 528 (defun hexl-maybe-dehexlify-buffer ()
 529   "Convert a hexl format buffer to binary.
 530 Ask the user for confirmation."
 531   (if (y-or-n-p "Convert contents back to binary format? ")
 532       (let ((modified (buffer-modified-p))
 533             (inhibit-read-only t)
 534             (original-point (1+ (hexl-current-address))))
 535         (dehexlify-buffer)
 536         (remove-hook 'write-contents-functions 'hexl-save-buffer t)
 537         (restore-buffer-modified-p modified)
 538         (goto-char original-point))))
 539
 540 (defun hexl-current-address (&optional validate)
 541   "Return current hexl-address."
 542   (interactive)
 543   (let ((current-column
 544          (- (% (- (point) (point-min) -1) (hexl-line-displen)) 11))
 545         (hexl-address 0))
 546     (if (< current-column 0)
 547         (if validate
 548             (error "Point is not on a character in the file")
 549           (setq current-column 0)))
 550     (setq hexl-address
 551           (+ (* (/ (- (point) (point-min) -1)
 552                    (hexl-line-displen)) 16)
 553              (if (>= current-column (- (hexl-ascii-start-column) 10))
 554                  (- current-column (- (hexl-ascii-start-column) 10))
 555                (/ (- current-column
 556                      (/ current-column (1+ (/ hexl-bits 4)))) 2))))
 557     (when (called-interactively-p 'interactive)
 558       (message "Current address is %d/0x%08x" hexl-address hexl-address))
 559     hexl-address))
 560
 561 (defun hexl-print-current-point-info ()
 562   "Return current hexl-address in string.
 563 This function is intended to be used as eldoc callback."
 564   (let ((addr (hexl-current-address)))
 565     (format "Current address is %d/0x%08x" addr addr)))
 566
 567 (defun hexl-ascii-start-column ()
 568   "Column at which the ascii portion of the hexl display starts."
 569   (+ 43 (/ 128 hexl-bits)))
 570
 571 (defun hexl-address-to-marker (address)
 572   "Return buffer position for ADDRESS."
 573   (interactive "nAddress: ")
 574   (let ((N (* (% address 16) 2)))
 575     (+ (* (/ address 16) (hexl-line-displen)) ; hexl line no * display length
 576        10                      ; 10 chars for the "address: " prefix
 577        (point-min)             ; base offset (point usually starts at 1, not 0)
 578        (+ N (/ N (/ hexl-bits 4))) )) ) ; char offset into hexl display line
 579
 580 (defun hexl-goto-address (address)
 581   "Go to hexl-mode (decimal) address ADDRESS.
 582 Signal error if ADDRESS is out of range."
 583   (interactive "nAddress: ")
 584   (if (or (< address 0) (> address hexl-max-address))
 585       (error "Out of hexl region"))
 586   (goto-char (hexl-address-to-marker address)))
 587
 588 (defun hexl-goto-hex-address (hex-address)
 589   "Go to hexl-mode address (hex string) HEX-ADDRESS.
 590 Signal error if HEX-ADDRESS is out of range."
 591   (interactive "sHex Address: ")
 592   (hexl-goto-address (hexl-hex-string-to-integer hex-address)))
 593
 594 (defun hexl-hex-string-to-integer (hex-string)
 595   "Return decimal integer for HEX-STRING."
 596   (interactive "sHex number: ")
 597   (let ((hex-num 0))
 598     (while (not (equal hex-string ""))
 599       (setq hex-num (+ (* hex-num 16)
 600                        (hexl-hex-char-to-integer (string-to-char hex-string))))
 601       (setq hex-string (substring hex-string 1)))
 602     hex-num))
 603
 604 (defun hexl-octal-string-to-integer (octal-string)
 605   "Return decimal integer for OCTAL-STRING."
 606   (interactive "sOctal number: ")
 607   (let ((oct-num 0))
 608     (while (not (equal octal-string ""))
 609       (setq oct-num (+ (* oct-num 8)
 610                        (hexl-oct-char-to-integer
 611                         (string-to-char octal-string))))
 612       (setq octal-string (substring octal-string 1)))
 613     oct-num))
 614
 615 ;; move point functions
 616
 617 (defun hexl-backward-char (arg)
 618   "Move to left ARG bytes (right if ARG negative) in hexl-mode."
 619   (interactive "p")
 620   (hexl-goto-address (- (hexl-current-address) arg)))
 621
 622 (defun hexl-forward-char (arg)
 623   "Move to right ARG bytes (left if ARG negative) in hexl-mode."
 624   (interactive "p")
 625   (hexl-goto-address (+ (hexl-current-address) arg)))
 626
 627 (defun hexl-backward-short (arg)
 628   "Move to left ARG shorts (right if ARG negative) in hexl-mode."
 629   (interactive "p")
 630   (hexl-goto-address (let ((address (hexl-current-address)))
 631                        (if (< arg 0)
 632                            (progn
 633                              (setq arg (- arg))
 634                              (while (> arg 0)
 635                                (setq address
 636                                      (if (> address hexl-max-address)
 637                                          (progn
 638                                            (message "End of buffer.")
 639                                            hexl-max-address)
 640                                        (if (equal address (logior address 3))
 641                                            (+ address 4)
 642                                          (logior address 3))))
 643                                (setq arg (1- arg)))
 644                              (setq address
 645                                    (if (> address hexl-max-address)
 646                                        (progn
 647                                          (message "End of buffer.")
 648                                          hexl-max-address)
 649                                      (logior address 3))))
 650                          (while (> arg 0)
 651                            (if (not (equal address (logand address -4)))
 652                                (setq address (logand address -4))
 653                              (if (not (equal address 0))
 654                                  (setq address (- address 4))
 655                                (message "Beginning of buffer.")))
 656                            (setq arg (1- arg))))
 657                        address)))
 658
 659 (defun hexl-forward-short (arg)
 660   "Move to right ARG shorts (left if ARG negative) in hexl-mode."
 661   (interactive "p")
 662   (hexl-backward-short (- arg)))
 663
 664 (defun hexl-backward-word (arg)
 665   "Move to left ARG words (right if ARG negative) in hexl-mode."
 666   (interactive "p")
 667   (hexl-goto-address (let ((address (hexl-current-address)))
 668                        (if (< arg 0)
 669                            (progn
 670                              (setq arg (- arg))
 671                              (while (> arg 0)
 672                                (setq address
 673                                      (if (> address hexl-max-address)
 674                                          (progn
 675                                            (message "End of buffer.")
 676                                            hexl-max-address)
 677                                        (if (equal address (logior address 7))
 678                                            (+ address 8)
 679                                          (logior address 7))))
 680                                (setq arg (1- arg)))
 681                              (setq address
 682                                    (if (> address hexl-max-address)
 683                                        (progn
 684                                          (message "End of buffer.")
 685                                          hexl-max-address)
 686                                      (logior address 7))))
 687                          (while (> arg 0)
 688                            (if (not (equal address (logand address -8)))
 689                                (setq address (logand address -8))
 690                              (if (not (equal address 0))
 691                                  (setq address (- address 8))
 692                                (message "Beginning of buffer.")))
 693                            (setq arg (1- arg))))
 694                        address)))
 695
 696 (defun hexl-forward-word (arg)
 697   "Move to right ARG words (left if ARG negative) in hexl-mode."
 698   (interactive "p")
 699   (hexl-backward-word (- arg)))
 700
 701 (defun hexl-previous-line (arg)
 702   "Move vertically up ARG lines [16 bytes] (down if ARG negative) in hexl-mode.
 703 If there is no byte at the target address move to the last byte in that line."
 704   (interactive "p")
 705   (hexl-next-line (- arg)))
 706
 707 (defun hexl-next-line (arg)
 708   "Move vertically down ARG lines [16 bytes] (up if ARG negative) in hexl-mode.
 709 If there is no byte at the target address move to the last byte in that line."
 710   (interactive "p")
 711   (hexl-goto-address (let ((address (+ (hexl-current-address) (* arg 16))))
 712                        (if (and (< arg 0) (< address 0))
 713                                 (progn (message "Out of hexl region.")
 714                                        (setq address
 715                                              (% (hexl-current-address) 16)))
 716                          (if (and (> address hexl-max-address)
 717                                   (< (% hexl-max-address 16) (% address 16)))
 718                              (setq address hexl-max-address)
 719                            (if (> address hexl-max-address)
 720                                (progn (message "Out of hexl region.")
 721                                       (setq
 722                                        address
 723                                        (+ (logand hexl-max-address -16)
 724                                           (% (hexl-current-address) 16)))))))
 725                        address)))
 726
 727 (defun hexl-beginning-of-buffer (arg)
 728   "Move to the beginning of the hexl buffer.
 729 Leaves `hexl-mark' at previous position.
 730 With prefix arg N, puts point N bytes of the way from the true beginning."
 731   (interactive "p")
 732   (push-mark (point))
 733   (hexl-goto-address (+ 0 (1- arg))))
 734
 735 (defun hexl-end-of-buffer (arg)
 736   "Go to `hexl-max-address' minus ARG."
 737   (interactive "p")
 738   (push-mark (point))
 739   (hexl-goto-address (- hexl-max-address (1- arg))))
 740
 741 (defun hexl-beginning-of-line ()
 742   "Goto beginning of line in hexl mode."
 743   (interactive)
 744   (goto-char (+ (* (/ (point) (hexl-line-displen)) (hexl-line-displen)) 11)))
 745
 746 (defun hexl-end-of-line ()
 747   "Goto end of line in hexl mode."
 748   (interactive)
 749   (hexl-goto-address (let ((address (logior (hexl-current-address) 15)))
 750                        (if (> address hexl-max-address)
 751                            (setq address hexl-max-address))
 752                        address)))
 753
 754 (defun hexl-scroll-down (arg)
 755   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG."
 756   (interactive "P")
 757   (setq arg (if (null arg)
 758                 (1- (window-height))
 759               (prefix-numeric-value arg)))
 760   (hexl-scroll-up (- arg)))
 761
 762 (defun hexl-scroll-up (arg)
 763   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG.
 764 If there's no byte at the target address, move to the first or last line."
 765   (interactive "P")
 766   (setq arg (if (null arg)
 767                 (1- (window-height))
 768               (prefix-numeric-value arg)))
 769   (let* ((movement (* arg 16))
 770          (address (hexl-current-address))
 771          (dest (+ address movement)))
 772     (cond
 773      ;; If possible, try to stay at the same offset from the beginning
 774      ;; of the 16-byte group, even if we move to the first or last
 775      ;; group.
 776      ((and (> dest hexl-max-address)
 777            (>= (% hexl-max-address 16) (% address 16)))
 778       (setq dest (+ (logand hexl-max-address -16) (% address 16))))
 779      ((> dest hexl-max-address)
 780       (setq dest hexl-max-address))
 781      ((< dest 0)
 782       (setq dest (% address 16))))
 783     (if (/= dest (+ address movement))
 784         (message "Out of hexl region."))
 785     (hexl-goto-address dest)
 786     (recenter 0)))
 787
 788 (defun hexl-beginning-of-1k-page ()
 789   "Go to beginning of 1KB boundary."
 790   (interactive)
 791   (hexl-goto-address (logand (hexl-current-address) -1024)))
 792
 793 (defun hexl-end-of-1k-page ()
 794   "Go to end of 1KB boundary."
 795   (interactive)
 796   (hexl-goto-address
 797    (max hexl-max-address (logior (hexl-current-address) 1023))))
 798
 799 (defun hexl-beginning-of-512b-page ()
 800   "Go to beginning of 512 byte boundary."
 801   (interactive)
 802   (hexl-goto-address (logand (hexl-current-address) -512)))
 803
 804 (defun hexl-end-of-512b-page ()
 805   "Go to end of 512 byte boundary."
 806   (interactive)
 807   (hexl-goto-address
 808    (max hexl-max-address (logior (hexl-current-address) 511))))
 809
 810 (defun hexl-quoted-insert (arg)
 811   "Read next input character and insert it.
 812 Useful for inserting control characters and non-ASCII characters given their
 813 numerical code.
 814 You may also type octal digits, to insert a character with that code."
 815   (interactive "p")
 816   (hexl-insert-multibyte-char (read-quoted-char) arg))
 817
 818 ;00000000: 0011 2233 4455 6677 8899 aabb ccdd eeff  0123456789ABCDEF
 819
 820 (defun hexl-options (&optional test)
 821   "Combine `hexl-bits' with `hexl-options', altering `hexl-options' as needed
 822 to produce the command line options to pass to the hexl command."
 823   (let ((opts (or test hexl-options)))
 824     (when (memq hexl-bits '(8 16 32 64))
 825       (when (string-match "\\(.*\\)-group-by-[0-9]+-bits\\(.*\\)" opts)
 826         (setq opts (concat (match-string 1 opts)
 827                            (match-string 2 opts))))
 828       (setq opts (format "%s -group-by-%d-bits " opts hexl-bits)) )
 829     opts))
 830
 831 ;;;###autoload
 832 (defun hexlify-buffer ()
 833   "Convert a binary buffer to hexl format.
 834 This discards the buffer's undo information."
 835   (interactive)
 836   (and (consp buffer-undo-list)
 837        (or (y-or-n-p "Converting to hexl format discards undo info; ok? ")
 838            (error "Aborted"))
 839        (setq buffer-undo-list nil))
 840   ;; Don't decode text in the ASCII part of `hexl' program output.
 841   (let ((coding-system-for-read 'raw-text)
 842         (coding-system-for-write buffer-file-coding-system)
 843         (buffer-undo-list t))
 844     (apply 'call-process-region (point-min) (point-max)
 845            (expand-file-name hexl-program exec-directory)
 846            t t nil
 847            ;; Manually encode the args, otherwise they're encoded using
 848            ;; coding-system-for-write (i.e. buffer-file-coding-system) which
 849            ;; may not be what we want (e.g. utf-16 on a non-utf-16 system).
 850            (mapcar (lambda (s)
 851                      (if (not (multibyte-string-p s)) s
 852                        (encode-coding-string s locale-coding-system)))
 853                    (split-string (hexl-options))))
 854     (if (> (point) (hexl-address-to-marker hexl-max-address))
 855         (hexl-goto-address hexl-max-address))))
 856
 857 (defun dehexlify-buffer ()
 858   "Convert a hexl format buffer to binary.
 859 This discards the buffer's undo information."
 860   (interactive)
 861   (and (consp buffer-undo-list)
 862        (or (y-or-n-p "Converting from hexl format discards undo info; ok? ")
 863            (error "Aborted"))
 864        (setq buffer-undo-list nil))
 865   (let ((coding-system-for-write 'raw-text)
 866         (coding-system-for-read buffer-file-coding-system)
 867         (buffer-undo-list t))
 868     (apply 'call-process-region (point-min) (point-max)
 869            (expand-file-name hexl-program exec-directory)
 870            t t nil "-de" (split-string (hexl-options)))))
 871
 872 (defun hexl-char-after-point ()
 873   "Return char for ASCII hex digits at point."
 874   (hexl-htoi (char-after (point))
 875              (char-after (1+ (point)))))
 876
 877 (defun hexl-htoi (lh rh)
 878   "Hex (char) LH (char) RH to integer."
 879     (+ (* (hexl-hex-char-to-integer lh) 16)
 880        (hexl-hex-char-to-integer rh)))
 881
 882 (defun hexl-hex-char-to-integer (character)
 883   "Take a char and return its value as if it was a hex digit."
 884   (if (and (>= character ?0) (<= character ?9))
 885       (- character ?0)
 886     (let ((ch (logior character 32)))
 887       (if (and (>= ch ?a) (<= ch ?f))
 888           (- ch (- ?a 10))
 889         (error "Invalid hex digit `%c'" ch)))))
 890
 891 (defun hexl-oct-char-to-integer (character)
 892   "Take a char and return its value as if it was a octal digit."
 893   (if (and (>= character ?0) (<= character ?7))
 894       (- character ?0)
 895     (error "Invalid octal digit `%c'" character)))
 896
 897 (defun hexl-printable-character (ch)
 898   "Return a displayable string for character CH."
 899   (format "%c" (if (equal hexl-iso "")
 900                    (if (or (< ch 32) (>= ch 127))
 901                        46
 902                      ch)
 903                  (if (or (< ch 32) (and (>= ch 127) (< ch 160)))
 904                      46
 905                    ch))))
 906
 907 (defun hexl-insert-multibyte-char (ch num)
 908   "Insert a possibly multibyte character CH NUM times.
 909
 910 Non-ASCII characters are first encoded with `buffer-file-coding-system',
 911 and their encoded form is inserted byte by byte."
 912   (let ((charset (char-charset ch))
 913         (coding (if (or (null buffer-file-coding-system)
 914                         ;; coding-system-type equals t means undecided.
 915                         (eq (coding-system-type buffer-file-coding-system) t))
 916                     (default-value 'buffer-file-coding-system)
 917                   buffer-file-coding-system)))
 918     (cond ((and (> ch 0) (< ch 256))
 919            (hexl-insert-char ch num))
 920           ((eq charset 'unknown)
 921            (error
 922             "0x%x -- invalid character code; use \\[hexl-insert-hex-string]"
 923             ch))
 924           (t
 925            (let ((encoded (encode-coding-char ch coding))
 926                  (internal (string-as-unibyte (char-to-string ch)))
 927                  internal-hex)
 928              ;; If encode-coding-char returns nil, it means our character
 929              ;; cannot be safely encoded with buffer-file-coding-system.
 930              ;; In that case, we offer to insert the internal representation
 931              ;; of that character, byte by byte.
 932              (when (null encoded)
 933                (setq internal-hex
 934                      (mapconcat (function (lambda (c) (format "%x" c)))
 935                                 internal " "))
 936                (if (yes-or-no-p
 937                     (format
 938                      "Insert char 0x%x's internal representation \"%s\"? "
 939                      ch internal-hex))
 940                    (setq encoded internal)
 941                  (error
 942                   "Can't encode `0x%x' with this buffer's coding system; try \\[hexl-insert-hex-string]"
 943                   ch)))
 944              (while (> num 0)
 945                (mapc
 946                 (function (lambda (c) (hexl-insert-char c 1))) encoded)
 947                (setq num (1- num))))))))
 948
 949 (defun hexl-self-insert-command (arg)
 950   "Insert this character.
 951 Interactively, with a numeric argument, insert this character that many times.
 952
 953 Non-ASCII characters are first encoded with `buffer-file-coding-system',
 954 and their encoded form is inserted byte by byte."
 955   (interactive "p")
 956   (hexl-insert-multibyte-char last-command-event arg))
 957
 958 (defun hexl-insert-char (ch num)
 959   "Insert the character CH NUM times in a hexl buffer.
 960
 961 CH must be a unibyte character whose value is between 0 and 255."
 962   (if (or (< ch 0) (> ch 255))
 963       (error "Invalid character 0x%x -- must be in the range [0..255]" ch))
 964   (let ((address (hexl-current-address t)))
 965     (while (> num 0)
 966       (let ((hex-position (hexl-address-to-marker address))
 967             (ascii-position
 968              (+ (* (/ address 16) (hexl-line-displen))
 969                 (hexl-ascii-start-column)
 970                 (point-min)
 971                 (% address 16)))
 972             at-ascii-position)
 973         (if (= (point) ascii-position)
 974             (setq at-ascii-position t))
 975         (goto-char hex-position)
 976         (delete-char 2)
 977         (insert (format "%02x" ch))
 978         (goto-char ascii-position)
 979         (delete-char 1)
 980         (insert (hexl-printable-character ch))
 981         (or (eq address hexl-max-address)
 982             (setq address (1+ address)))
 983         (hexl-goto-address address)
 984         (if at-ascii-position
 985             (progn
 986               (beginning-of-line)
 987               (forward-char (hexl-ascii-start-column))
 988               (forward-char (% address 16)))))
 989       (setq num (1- num)))))
 990
 991 ;; hex conversion
 992
 993 (defun hexl-insert-hex-char (arg)
 994   "Insert a character given by its hexadecimal code ARG times at point."
 995   (interactive "p")
 996   (let ((num (hexl-hex-string-to-integer (read-string "Hex number: "))))
 997     (if (< num 0)
 998         (error "Hex number out of range")
 999       (hexl-insert-multibyte-char num arg))))
1000
1001 (defun hexl-insert-hex-string (str arg)
1002   "Insert hexadecimal string STR at point ARG times.
1003 Embedded whitespace, dashes, and periods in the string are ignored."
1004   (interactive "sHex string: \np")
1005   (setq str (replace-regexp-in-string "[- \t.]" "" str))
1006   (let ((chars '()))
1007     (let ((len (length str))
1008           (idx 0))
1009       (if (eq (logand len 1) 1)
1010           (let ((num (hexl-hex-string-to-integer (substring str 0 1))))
1011             (setq chars (cons num chars))
1012             (setq idx 1)))
1013       (while (< idx len)
1014         (let* ((nidx (+ idx 2))
1015                (num (hexl-hex-string-to-integer (substring str idx nidx))))
1016           (setq chars (cons num chars))
1017           (setq idx nidx))))
1018     (setq chars (nreverse chars))
1019     (while (> arg 0)
1020       (let ((chars chars))
1021         (while chars
1022           (hexl-insert-char (car chars) 1)
1023           (setq chars (cdr chars))))
1024       (setq arg (- arg 1)))))
1025
1026 (defun hexl-insert-decimal-char (arg)
1027   "Insert a character given by its decimal code ARG times at point."
1028   (interactive "p")
1029   (let ((num (string-to-number (read-string "Decimal Number: "))))
1030     (if (< num 0)
1031         (error "Decimal number out of range")
1032       (hexl-insert-multibyte-char num arg))))
1033
1034 (defun hexl-insert-octal-char (arg)
1035   "Insert a character given by its octal code ARG times at point."
1036   (interactive "p")
1037   (let ((num (hexl-octal-string-to-integer (read-string "Octal Number: "))))
1038     (if (< num 0)
1039         (error "Decimal number out of range")
1040       (hexl-insert-multibyte-char num arg))))
1041
1042 (defun hexl-follow-ascii (&optional arg)
1043   "Toggle following ASCII in Hexl buffers.
1044 With prefix ARG, turn on following if and only if ARG is positive.
1045 When following is enabled, the ASCII character corresponding to the
1046 element under the point is highlighted.
1047 Customize the variable `hexl-follow-ascii' to disable this feature."
1048   (interactive "P")
1049   (let ((on-p (if arg
1050                   (> (prefix-numeric-value arg) 0)
1051                (not hexl-ascii-overlay))))
1052
1053     (if on-p
1054       ;; turn it on
1055       (if (not hexl-ascii-overlay)
1056           (progn
1057             (setq hexl-ascii-overlay (make-overlay 1 1)
1058                   hexl-follow-ascii t)
1059             (overlay-put hexl-ascii-overlay 'face 'highlight)
1060             (add-hook 'post-command-hook 'hexl-follow-ascii-find nil t)))
1061       ;; turn it off
1062       (if hexl-ascii-overlay
1063           (progn
1064             (delete-overlay hexl-ascii-overlay)
1065             (setq hexl-ascii-overlay nil
1066                   hexl-follow-ascii nil)
1067             (remove-hook 'post-command-hook 'hexl-follow-ascii-find t)
1068             )))))
1069
1070 (defun hexl-activate-ruler ()
1071   "Activate `ruler-mode'."
1072   (require 'ruler-mode)
1073   (hexl-mode--setq-local 'ruler-mode-ruler-function
1074                          #'hexl-mode-ruler)
1075   (hexl-mode--setq-local 'ruler-mode t))
1076
1077 (defun hexl-follow-line ()
1078   "Activate `hl-line-mode'."
1079   (require 'hl-line)
1080   (hexl-mode--setq-local 'hl-line-range-function
1081                          #'hexl-highlight-line-range)
1082   (hexl-mode--setq-local 'hl-line-face 'highlight)
1083   (hexl-mode--setq-local 'hl-line-mode t))
1084
1085 (defun hexl-highlight-line-range ()
1086   "Return the range of address region for the point.
1087 This function is assumed to be used as callback function for `hl-line-mode'."
1088   (cons
1089    (line-beginning-position)
1090    ;; 9 stands for (length "87654321:")
1091    (+ (line-beginning-position) 9)))
1092
1093 (defun hexl-follow-ascii-find ()
1094   "Find and highlight the ASCII element corresponding to current point."
1095   (let ((pos (+ (hexl-ascii-start-column)
1096                 (- (point) (current-column))
1097                 (mod (hexl-current-address) 16))))
1098     (move-overlay hexl-ascii-overlay pos (1+ pos))
1099     ))
1100
1101 (defun hexl-mode-ruler ()
1102   "Return a string ruler for hexl mode."
1103   (let* ((highlight (mod (hexl-current-address) 16))
1104          (s (cdr (assq hexl-bits hexl-rulers)))
1105          (pos 0))
1106     (set-text-properties 0 (length s) nil s)
1107     ;; Turn spaces in the header into stretch specs so they work
1108     ;; regardless of the header-line face.
1109     (while (string-match "[ \t]+" s pos)
1110       (setq pos (match-end 0))
1111       (put-text-property (match-beginning 0) pos 'display
1112                          ;; Assume fixed-size chars
1113                          `(space :align-to ,(1- pos))
1114                          s))
1115     ;; Highlight the current column.
1116     (let ( (offset (+ (* 2 highlight) (/ (* 8 highlight) hexl-bits))) )
1117       (put-text-property (+ 11 offset) (+ 13 offset) 'face 'highlight s))
1118     ;; Highlight the current ascii column
1119     (put-text-property (+ (hexl-ascii-start-column) highlight 1)
1120                        (+ (hexl-ascii-start-column) highlight 2)
1121                        'face 'highlight s)
1122     s))
1123
1124 ;; startup stuff.
1125
1126 (easy-menu-define hexl-menu hexl-mode-map "Hexl Mode menu"
1127   `("Hexl"
1128     :help "Hexl-specific Features"
1129
1130     ["Backward short" hexl-backward-short
1131      :help "Move to left a short"]
1132     ["Forward short" hexl-forward-short
1133      :help "Move to right a short"]
1134     ["Backward word" hexl-backward-short
1135      :help "Move to left a word"]
1136     ["Forward word" hexl-forward-short
1137      :help "Move to right a word"]
1138     "-"
1139     ["Beginning of 512b page" hexl-beginning-of-512b-page
1140      :help "Go to beginning of 512 byte boundary"]
1141     ["End of 512b page" hexl-end-of-512b-page
1142      :help "Go to end of 512 byte boundary"]
1143     ["Beginning of 1K page" hexl-beginning-of-1k-page
1144      :help "Go to beginning of 1KB boundary"]
1145     ["End of 1K page" hexl-end-of-1k-page
1146      :help "Go to end of 1KB boundary"]
1147     "-"
1148     ["Go to address" hexl-goto-address
1149      :help "Go to hexl-mode (decimal) address"]
1150     ["Go to address" hexl-goto-hex-address
1151      :help "Go to hexl-mode (hex string) address"]
1152     "-"
1153     ["Insert decimal char" hexl-insert-decimal-char
1154      :help "Insert a character given by its decimal code"]
1155     ["Insert hex char" hexl-insert-hex-char
1156      :help "Insert a character given by its hexadecimal code"]
1157     ["Insert octal char" hexl-insert-octal-char
1158      :help "Insert a character given by its octal code"]
1159     "-"
1160     ["Exit hexl mode" hexl-mode-exit
1161      :help "Exit hexl mode returning to previous mode"]))
1162
1163 (provide 'hexl)
1164
1165 ;;; hexl.el ends here