lisp/hexl.el

   1 ;;; hexl.el --- edit a file in a hex dump format using the hexl filter.
   2
   3 ;; Copyright (C) 1989, 1994, 1998 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 2, or (at your option)
  14 ;; 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; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; This package implements a major mode for editing binary files.  It uses
  29 ;; a program called hexl, supplied with the GNU Emacs distribution, that
  30 ;; can filter a binary into an editable format or from the format back into
  31 ;; binary.  For full instructions, invoke `hexl-mode' on an empty buffer and
  32 ;; do `M-x describe-mode'.
  33 ;;
  34 ;; This may be useful in your .emacs:
  35 ;;
  36 ;;      (autoload 'hexl-find-file "hexl"
  37 ;;        "Edit file FILENAME in hexl-mode." t)
  38 ;;
  39 ;;      (define-key global-map "\C-c\C-h" 'hexl-find-file)
  40 ;;
  41 ;; NOTE: Remember to change HEXL-PROGRAM or HEXL-OPTIONS if needed.
  42 ;;
  43 ;; Currently hexl only supports big endian hex output with 16 bit
  44 ;; grouping.
  45 ;;
  46 ;; -iso in `hexl-options' will allow iso characters to display in the
  47 ;; ASCII region of the screen (if your emacs supports this) instead of
  48 ;; changing them to dots.
  49
  50 ;;; Code:
  51
  52 ;;
  53 ;; vars here
  54 ;;
  55
  56 (defgroup hexl nil
  57   "Edit a file in a hex dump format using the hexl filter."
  58   :group 'data)
  59
  60
  61 (defcustom hexl-program "hexl"
  62   "The program that will hexlify and dehexlify its stdin.
  63 `hexl-program' will always be concatenated with `hexl-options'
  64 and \"-de\" when dehexlifying a buffer."
  65   :type 'string
  66   :group 'hexl)
  67
  68 (defcustom hexl-iso ""
  69   "If your emacs can handle ISO characters, this should be set to
  70 \"-iso\" otherwise it should be \"\"."
  71   :type 'string
  72   :group 'hexl)
  73
  74 (defcustom hexl-options (format "-hex %s" hexl-iso)
  75   "Options to hexl-program that suit your needs."
  76   :type 'string
  77   :group 'hexl)
  78
  79 (defcustom hexlify-command
  80   (format "%s %s"
  81           (shell-quote-argument
  82            (expand-file-name hexl-program exec-directory))
  83           hexl-options)
  84   "The command to use to hexlify a buffer."
  85   :type 'string
  86   :group 'hexl)
  87
  88 (defcustom dehexlify-command
  89   (format "%s -de %s"
  90           (shell-quote-argument
  91            (expand-file-name hexl-program exec-directory))
  92           hexl-options)
  93   "The command to use to unhexlify a buffer."
  94   :type 'string
  95   :group 'hexl)
  96
  97 (defcustom hexl-follow-ascii t
  98   "If non-nil then highlight the ASCII character corresponding to point."
  99   :type 'boolean
 100   :group 'hexl
 101   :version "20.3")
 102
 103 (defvar hexl-max-address 0
 104   "Maximum offset into hexl buffer.")
 105
 106 (defvar hexl-mode-map nil)
 107
 108 (defvar hexl-mode-old-local-map)
 109 (defvar hexl-mode-old-mode-name)
 110 (defvar hexl-mode-old-major-mode)
 111 (defvar hexl-mode-old-write-contents-hooks)
 112 (defvar hexl-mode-old-require-final-newline)
 113 (defvar hexl-mode-old-syntax-table)
 114
 115 (defvar hexl-ascii-overlay nil
 116   "Overlay used to highlight ASCII element corresponding to current point.")
 117 (make-variable-buffer-local 'hexl-ascii-overlay)
 118
 119 ;; routines
 120
 121 (put 'hexl-mode 'mode-class 'special)
 122
 123 ;;;###autoload
 124 (defun hexl-mode (&optional arg)
 125   "\\<hexl-mode-map>
 126 A major mode for editing binary files in hex dump format.
 127
 128 This function automatically converts a buffer into the hexl format
 129 using the function `hexlify-buffer'.
 130
 131 Each line in the buffer has an \"address\" (displayed in hexadecimal)
 132 representing the offset into the file that the characters on this line
 133 are at and 16 characters from the file (displayed as hexadecimal
 134 values grouped every 16 bits) and as their ASCII values.
 135
 136 If any of the characters (displayed as ASCII characters) are
 137 unprintable (control or meta characters) they will be replaced as
 138 periods.
 139
 140 If `hexl-mode' is invoked with an argument the buffer is assumed to be
 141 in hexl format.
 142
 143 A sample format:
 144
 145   HEX ADDR: 0001 0203 0405 0607 0809 0a0b 0c0d 0e0f     ASCII-TEXT
 146   --------  ---- ---- ---- ---- ---- ---- ---- ----  ----------------
 147   00000000: 5468 6973 2069 7320 6865 786c 2d6d 6f64  This is hexl-mod
 148   00000010: 652e 2020 4561 6368 206c 696e 6520 7265  e.  Each line re
 149   00000020: 7072 6573 656e 7473 2031 3620 6279 7465  presents 16 byte
 150   00000030: 7320 6173 2068 6578 6164 6563 696d 616c  s as hexadecimal
 151   00000040: 2041 5343 4949 0a61 6e64 2070 7269 6e74   ASCII.and print
 152   00000050: 6162 6c65 2041 5343 4949 2063 6861 7261  able ASCII chara
 153   00000060: 6374 6572 732e 2020 416e 7920 636f 6e74  cters.  Any cont
 154   00000070: 726f 6c20 6f72 206e 6f6e 2d41 5343 4949  rol or non-ASCII
 155   00000080: 2063 6861 7261 6374 6572 730a 6172 6520   characters.are
 156   00000090: 6469 7370 6c61 7965 6420 6173 2070 6572  displayed as per
 157   000000a0: 696f 6473 2069 6e20 7468 6520 7072 696e  iods in the prin
 158   000000b0: 7461 626c 6520 6368 6172 6163 7465 7220  table character
 159   000000c0: 7265 6769 6f6e 2e0a                      region..
 160
 161 Movement is as simple as movement in a normal emacs text buffer.  Most
 162 cursor movement bindings are the same (ie. Use \\[hexl-backward-char], \\[hexl-forward-char], \\[hexl-next-line], and \\[hexl-previous-line]
 163 to move the cursor left, right, down, and up).
 164
 165 Advanced cursor movement commands (ala \\[hexl-beginning-of-line], \\[hexl-end-of-line], \\[hexl-beginning-of-buffer], and \\[hexl-end-of-buffer]) are
 166 also supported.
 167
 168 There are several ways to change text in hexl mode:
 169
 170 ASCII characters (character between space (0x20) and tilde (0x7E)) are
 171 bound to self-insert so you can simply type the character and it will
 172 insert itself (actually overstrike) into the buffer.
 173
 174 \\[hexl-quoted-insert] followed by another keystroke allows you to insert the key even if
 175 it isn't bound to self-insert.  An octal number can be supplied in place
 176 of another key to insert the octal number's ASCII representation.
 177
 178 \\[hexl-insert-hex-char] will insert a given hexadecimal value (if it is between 0 and 0xFF)
 179 into the buffer at the current point.
 180
 181 \\[hexl-insert-octal-char] will insert a given octal value (if it is between 0 and 0377)
 182 into the buffer at the current point.
 183
 184 \\[hexl-insert-decimal-char] will insert a given decimal value (if it is between 0 and 255)
 185 into the buffer at the current point.
 186
 187 \\[hexl-mode-exit] will exit hexl-mode.
 188
 189 Note: saving the file with any of the usual Emacs commands
 190 will actually convert it back to binary format while saving.
 191
 192 You can use \\[hexl-find-file] to visit a file in hexl-mode.
 193
 194 \\[describe-bindings] for advanced commands."
 195   (interactive "p")
 196   (if (eq major-mode 'hexl-mode)
 197       (error "You are already in hexl mode")
 198
 199     (let ((modified (buffer-modified-p))
 200           (inhibit-read-only t)
 201           (original-point (1- (point)))
 202           max-address)
 203       (and (eobp) (not (bobp))
 204            (setq original-point (1- original-point)))
 205       (if (not (or (eq arg 1) (not arg)))
 206           ;; if no argument then we guess at hexl-max-address
 207           (setq max-address (+ (* (/ (1- (buffer-size)) 68) 16) 15))
 208         (setq max-address (1- (buffer-size)))
 209         (hexlify-buffer)
 210         (set-buffer-modified-p modified))
 211       (make-local-variable 'hexl-max-address)
 212       (setq hexl-max-address max-address)
 213       (hexl-goto-address original-point))
 214
 215     ;; We do not turn off the old major mode; instead we just
 216     ;; override most of it.  That way, we can restore it perfectly.
 217     (make-local-variable 'hexl-mode-old-local-map)
 218     (setq hexl-mode-old-local-map (current-local-map))
 219     (use-local-map hexl-mode-map)
 220
 221     (make-local-variable 'hexl-mode-old-mode-name)
 222     (setq hexl-mode-old-mode-name mode-name)
 223     (setq mode-name "Hexl")
 224
 225     (make-local-variable 'hexl-mode-old-major-mode)
 226     (setq hexl-mode-old-major-mode major-mode)
 227     (setq major-mode 'hexl-mode)
 228
 229     (make-local-variable 'hexl-mode-old-syntax-table)
 230     (setq hexl-mode-old-syntax-table (syntax-table))
 231     (set-syntax-table (standard-syntax-table))
 232
 233     (make-local-variable 'hexl-mode-old-write-contents-hooks)
 234     (setq hexl-mode-old-write-contents-hooks write-contents-hooks)
 235     (make-local-variable 'write-contents-hooks)
 236     (add-hook 'write-contents-hooks 'hexl-save-buffer)
 237
 238     (make-local-variable 'hexl-mode-old-require-final-newline)
 239     (setq hexl-mode-old-require-final-newline require-final-newline)
 240     (make-local-variable 'require-final-newline)
 241     (setq require-final-newline nil)
 242
 243     ;; Add hooks to rehexlify or dehexlify on various events.
 244     (make-local-hook 'after-revert-hook)
 245     (add-hook 'after-revert-hook 'hexl-after-revert-hook nil t)
 246
 247     (make-local-hook 'change-major-mode-hook)
 248     (add-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer nil t)
 249
 250     (if hexl-follow-ascii (hexl-follow-ascii 1)))
 251   (run-hooks 'hexl-mode-hook))
 252
 253 (defun hexl-after-revert-hook ()
 254   (hexlify-buffer)
 255   (set-buffer-modified-p nil))
 256
 257 (defvar hexl-in-save-buffer nil)
 258
 259 (defun hexl-save-buffer ()
 260   "Save a hexl format buffer as binary in visited file if modified."
 261   (interactive)
 262   (if hexl-in-save-buffer nil
 263     (set-buffer-modified-p (if (buffer-modified-p)
 264                                (save-excursion
 265                                  (let ((buf (generate-new-buffer " hexl"))
 266                                        (name (buffer-name))
 267                                        (file-name (buffer-file-name))
 268                                        (start (point-min))
 269                                        (end (point-max))
 270                                        modified)
 271                                    (set-buffer buf)
 272                                    (insert-buffer-substring name start end)
 273                                    (set-buffer name)
 274                                    (dehexlify-buffer)
 275                                    ;; Prevent infinite recursion.
 276                                    (let ((hexl-in-save-buffer t))
 277                                      (save-buffer))
 278                                    (setq modified (buffer-modified-p))
 279                                    (delete-region (point-min) (point-max))
 280                                    (insert-buffer-substring buf start end)
 281                                    (kill-buffer buf)
 282                                    modified))
 283                              (message "(No changes need to be saved)")
 284                              nil))
 285     ;; Return t to indicate we have saved t
 286     t))
 287
 288 ;;;###autoload
 289 (defun hexl-find-file (filename)
 290   "Edit file FILENAME in hexl-mode.
 291 Switch to a buffer visiting file FILENAME, creating one in none exists."
 292   (interactive "fFilename: ")
 293   (find-file-literally filename)
 294   (if (not (eq major-mode 'hexl-mode))
 295       (hexl-mode)))
 296
 297 (defun hexl-mode-exit (&optional arg)
 298   "Exit Hexl mode, returning to previous mode.
 299 With arg, don't unhexlify buffer."
 300   (interactive "p")
 301   (if (or (eq arg 1) (not arg))
 302       (let ((modified (buffer-modified-p))
 303             (inhibit-read-only t)
 304             (original-point (1+ (hexl-current-address))))
 305         (dehexlify-buffer)
 306         (remove-hook 'write-contents-hooks 'hexl-save-buffer)
 307         (set-buffer-modified-p modified)
 308         (goto-char original-point)))
 309
 310   (remove-hook 'after-revert-hook 'hexl-after-revert-hook t)
 311   (remove-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer t)
 312   (remove-hook 'post-command-hook 'hexl-follow-ascii-find t)
 313   (setq hexl-ascii-overlay nil)
 314
 315   (setq write-contents-hooks hexl-mode-old-write-contents-hooks)
 316   (setq require-final-newline hexl-mode-old-require-final-newline)
 317   (setq mode-name hexl-mode-old-mode-name)
 318   (use-local-map hexl-mode-old-local-map)
 319   (set-syntax-table hexl-mode-old-syntax-table)
 320   (setq major-mode hexl-mode-old-major-mode)
 321   (force-mode-line-update))
 322
 323 (defun hexl-maybe-dehexlify-buffer ()
 324   "Convert a hexl format buffer to binary.
 325 Ask the user for confirmation."
 326   (if (y-or-n-p "Convert contents back to binary format? ")
 327       (let ((modified (buffer-modified-p))
 328             (inhibit-read-only t)
 329             (original-point (1+ (hexl-current-address))))
 330         (dehexlify-buffer)
 331         (remove-hook 'write-contents-hooks 'hexl-save-buffer)
 332         (set-buffer-modified-p modified)
 333         (goto-char original-point))))
 334
 335 (defun hexl-current-address (&optional validate)
 336   "Return current hexl-address."
 337   (interactive)
 338   (let ((current-column (- (% (point) 68) 11))
 339         (hexl-address 0))
 340     (if (< current-column 0)
 341         (if validate
 342             (error "Point is not on a character in the file")
 343           (setq current-column 0)))
 344     (setq hexl-address
 345           (+ (* (/ (point) 68) 16)
 346              (if (>= current-column 41)
 347                  (- current-column 41)
 348                (/ (- current-column  (/ current-column 5)) 2))))
 349     hexl-address))
 350
 351 (defun hexl-address-to-marker (address)
 352   "Return marker for ADDRESS."
 353   (interactive "nAddress: ")
 354   (+ (* (/ address 16) 68) 11 (/ (* (% address 16) 5) 2)))
 355
 356 (defun hexl-goto-address (address)
 357   "Goto hexl-mode (decimal) address ADDRESS.
 358 Signal error if ADDRESS out of range."
 359   (interactive "nAddress: ")
 360   (if (or (< address 0) (> address hexl-max-address))
 361           (error "Out of hexl region"))
 362   (goto-char (hexl-address-to-marker address)))
 363
 364 (defun hexl-goto-hex-address (hex-address)
 365   "Go to hexl-mode address (hex string) HEX-ADDRESS.
 366 Signal error if HEX-ADDRESS is out of range."
 367   (interactive "sHex Address: ")
 368   (hexl-goto-address (hexl-hex-string-to-integer hex-address)))
 369
 370 (defun hexl-hex-string-to-integer (hex-string)
 371   "Return decimal integer for HEX-STRING."
 372   (interactive "sHex number: ")
 373   (let ((hex-num 0))
 374     (while (not (equal hex-string ""))
 375       (setq hex-num (+ (* hex-num 16)
 376                        (hexl-hex-char-to-integer (string-to-char hex-string))))
 377       (setq hex-string (substring hex-string 1)))
 378     hex-num))
 379
 380 (defun hexl-octal-string-to-integer (octal-string)
 381   "Return decimal integer for OCTAL-STRING."
 382   (interactive "sOctal number: ")
 383   (let ((oct-num 0))
 384     (while (not (equal octal-string ""))
 385       (setq oct-num (+ (* oct-num 8)
 386                        (hexl-oct-char-to-integer
 387                         (string-to-char octal-string))))
 388       (setq octal-string (substring octal-string 1)))
 389     oct-num))
 390
 391 ;; move point functions
 392
 393 (defun hexl-backward-char (arg)
 394   "Move to left ARG bytes (right if ARG negative) in hexl-mode."
 395   (interactive "p")
 396   (hexl-goto-address (- (hexl-current-address) arg)))
 397
 398 (defun hexl-forward-char (arg)
 399   "Move right ARG bytes (left if ARG negative) in hexl-mode."
 400   (interactive "p")
 401   (hexl-goto-address (+ (hexl-current-address) arg)))
 402
 403 (defun hexl-backward-short (arg)
 404   "Move to left ARG shorts (right if ARG negative) in hexl-mode."
 405   (interactive "p")
 406   (hexl-goto-address (let ((address (hexl-current-address)))
 407                        (if (< arg 0)
 408                            (progn
 409                              (setq arg (- arg))
 410                              (while (> arg 0)
 411                                (if (not (equal address (logior address 3)))
 412                                    (if (> address hexl-max-address)
 413                                        (progn
 414                                          (message "End of buffer.")
 415                                          (setq address hexl-max-address))
 416                                      (setq address (logior address 3)))
 417                                  (if (> address hexl-max-address)
 418                                      (progn
 419                                        (message "End of buffer.")
 420                                        (setq address hexl-max-address))
 421                                    (setq address (+ address 4))))
 422                                (setq arg (1- arg)))
 423                              (if (> address hexl-max-address)
 424                                  (progn
 425                                    (message "End of buffer.")
 426                                    (setq address hexl-max-address))
 427                                (setq address (logior address 3))))
 428                          (while (> arg 0)
 429                            (if (not (equal address (logand address -4)))
 430                                (setq address (logand address -4))
 431                              (if (not (equal address 0))
 432                                  (setq address (- address 4))
 433                                (message "Beginning of buffer.")))
 434                            (setq arg (1- arg))))
 435                        address)))
 436
 437 (defun hexl-forward-short (arg)
 438   "Move right ARG shorts (left if ARG negative) in hexl-mode."
 439   (interactive "p")
 440   (hexl-backward-short (- arg)))
 441
 442 (defun hexl-backward-word (arg)
 443   "Move to left ARG words (right if ARG negative) in hexl-mode."
 444   (interactive "p")
 445   (hexl-goto-address (let ((address (hexl-current-address)))
 446                        (if (< arg 0)
 447                            (progn
 448                              (setq arg (- arg))
 449                              (while (> arg 0)
 450                                (if (not (equal address (logior address 7)))
 451                                    (if (> address hexl-max-address)
 452                                        (progn
 453                                          (message "End of buffer.")
 454                                          (setq address hexl-max-address))
 455                                      (setq address (logior address 7)))
 456                                  (if (> address hexl-max-address)
 457                                      (progn
 458                                        (message "End of buffer.")
 459                                        (setq address hexl-max-address))
 460                                    (setq address (+ address 8))))
 461                                (setq arg (1- arg)))
 462                              (if (> address hexl-max-address)
 463                                  (progn
 464                                    (message "End of buffer.")
 465                                    (setq address hexl-max-address))
 466                                (setq address (logior address 7))))
 467                          (while (> arg 0)
 468                            (if (not (equal address (logand address -8)))
 469                                (setq address (logand address -8))
 470                              (if (not (equal address 0))
 471                                  (setq address (- address 8))
 472                                (message "Beginning of buffer.")))
 473                            (setq arg (1- arg))))
 474                        address)))
 475
 476 (defun hexl-forward-word (arg)
 477   "Move right ARG words (left if ARG negative) in hexl-mode."
 478   (interactive "p")
 479   (hexl-backward-word (- arg)))
 480
 481 (defun hexl-previous-line (arg)
 482   "Move vertically up ARG lines [16 bytes] (down if ARG negative) in hexl-mode.
 483 If there is byte at the target address move to the last byte in that line."
 484   (interactive "p")
 485   (hexl-next-line (- arg)))
 486
 487 (defun hexl-next-line (arg)
 488   "Move vertically down ARG lines [16 bytes] (up if ARG negative) in hexl-mode.
 489 If there is no byte at the target address move to the last byte in that line."
 490   (interactive "p")
 491   (hexl-goto-address (let ((address (+ (hexl-current-address) (* arg 16))))
 492                        (if (and (< arg 0) (< address 0))
 493                                 (progn (message "Out of hexl region.")
 494                                        (setq address
 495                                              (% (hexl-current-address) 16)))
 496                          (if (and (> address hexl-max-address)
 497                                   (< (% hexl-max-address 16) (% address 16)))
 498                              (setq address hexl-max-address)
 499                            (if (> address hexl-max-address)
 500                                (progn (message "Out of hexl region.")
 501                                       (setq
 502                                        address
 503                                        (+ (logand hexl-max-address -16)
 504                                           (% (hexl-current-address) 16)))))))
 505                        address)))
 506
 507 (defun hexl-beginning-of-buffer (arg)
 508   "Move to the beginning of the hexl buffer.
 509 Leaves `hexl-mark' at previous position.
 510 With prefix arg N, puts point N bytes of the way from the true beginning."
 511   (interactive "p")
 512   (push-mark (point))
 513   (hexl-goto-address (+ 0 (1- arg))))
 514
 515 (defun hexl-end-of-buffer (arg)
 516   "Go to `hexl-max-address' minus ARG."
 517   (interactive "p")
 518   (push-mark (point))
 519   (hexl-goto-address (- hexl-max-address (1- arg))))
 520
 521 (defun hexl-beginning-of-line ()
 522   "Goto beginning of line in hexl mode."
 523   (interactive)
 524   (goto-char (+ (* (/ (point) 68) 68) 11)))
 525
 526 (defun hexl-end-of-line ()
 527   "Goto end of line in hexl mode."
 528   (interactive)
 529   (hexl-goto-address (let ((address (logior (hexl-current-address) 15)))
 530                        (if (> address hexl-max-address)
 531                            (setq address hexl-max-address))
 532                        address)))
 533
 534 (defun hexl-scroll-down (arg)
 535   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG."
 536   (interactive "P")
 537   (if (null arg)
 538       (setq arg (1- (window-height)))
 539     (setq arg (prefix-numeric-value arg)))
 540   (hexl-scroll-up (- arg)))
 541
 542 (defun hexl-scroll-up (arg)
 543   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG."
 544   (interactive "P")
 545   (if (null arg)
 546       (setq arg (1- (window-height)))
 547     (setq arg (prefix-numeric-value arg)))
 548   (let ((movement (* arg 16))
 549         (address (hexl-current-address)))
 550     (if (or (> (+ address movement) hexl-max-address)
 551             (< (+ address movement) 0))
 552         (message "Out of hexl region.")
 553       (hexl-goto-address (+ address movement))
 554       (recenter 0))))
 555
 556 (defun hexl-beginning-of-1k-page ()
 557   "Go to beginning of 1k boundary."
 558   (interactive)
 559   (hexl-goto-address (logand (hexl-current-address) -1024)))
 560
 561 (defun hexl-end-of-1k-page ()
 562   "Go to end of 1k boundary."
 563   (interactive)
 564   (hexl-goto-address (let ((address (logior (hexl-current-address) 1023)))
 565                        (if (> address hexl-max-address)
 566                            (setq address hexl-max-address))
 567                        address)))
 568
 569 (defun hexl-beginning-of-512b-page ()
 570   "Go to beginning of 512 byte boundary."
 571   (interactive)
 572   (hexl-goto-address (logand (hexl-current-address) -512)))
 573
 574 (defun hexl-end-of-512b-page ()
 575   "Go to end of 512 byte boundary."
 576   (interactive)
 577   (hexl-goto-address (let ((address (logior (hexl-current-address) 511)))
 578                        (if (> address hexl-max-address)
 579                            (setq address hexl-max-address))
 580                        address)))
 581
 582 (defun hexl-quoted-insert (arg)
 583   "Read next input character and insert it.
 584 Useful for inserting control characters.
 585 You may also type up to 3 octal digits, to insert a character with that code"
 586   (interactive "p")
 587   (hexl-insert-char (read-quoted-char) arg))
 588
 589 ;00000000: 0011 2233 4455 6677 8899 aabb ccdd eeff  0123456789ABCDEF
 590
 591 ;;;###autoload
 592 (defun hexlify-buffer ()
 593   "Convert a binary buffer to hexl format.
 594 This discards the buffer's undo information."
 595   (interactive)
 596   (and buffer-undo-list
 597        (or (y-or-n-p "Converting to hexl format discards undo info; ok? ")
 598            (error "Aborted")))
 599   (setq buffer-undo-list nil)
 600   ;; Don't decode text in the ASCII part of `hexl' program output.
 601   (let ((coding-system-for-read 'raw-text)
 602         ;; If the buffer was read with EOL conversions, be sure to use the
 603         ;; same conversions when passing the region to the `hexl' program.
 604         (coding-system-for-write
 605          (let ((eol-type (coding-system-eol-type buffer-file-coding-system)))
 606            (cond ((eq eol-type 1)
 607                   'raw-text-dos)
 608                  ((eq eol-type 2)
 609                   'raw-text-mac)
 610                  ((eq eol-type 0)
 611                   'raw-text-unix)
 612                  (t 'no-conversion))))
 613         (buffer-undo-list t))
 614     (shell-command-on-region (point-min) (point-max) hexlify-command t)))
 615
 616 (defun dehexlify-buffer ()
 617   "Convert a hexl format buffer to binary.
 618 This discards the buffer's undo information."
 619   (interactive)
 620   (and buffer-undo-list
 621        (or (y-or-n-p "Converting from hexl format discards undo info; ok? ")
 622            (error "Aborted")))
 623   (setq buffer-undo-list nil)
 624   (let ((coding-system-for-write 'raw-text)
 625         (coding-system-for-read
 626          (let ((eol-type (coding-system-eol-type buffer-file-coding-system)))
 627            (cond ((eq eol-type 1)
 628                   'raw-text-dos)
 629                  ((eq eol-type 2)
 630                   'raw-text-mac)
 631                  ((eq eol-type 0)
 632                   'raw-text-unix)
 633                  (t 'no-conversion))))
 634         (buffer-undo-list t))
 635     (shell-command-on-region (point-min) (point-max) dehexlify-command t)))
 636
 637 (defun hexl-char-after-point ()
 638   "Return char for ASCII hex digits at point."
 639   (hexl-htoi (char-after (point))
 640              (char-after (1+ (point)))))
 641
 642 (defun hexl-htoi (lh rh)
 643   "Hex (char) LH (char) RH to integer."
 644     (+ (* (hexl-hex-char-to-integer lh) 16)
 645        (hexl-hex-char-to-integer rh)))
 646
 647 (defun hexl-hex-char-to-integer (character)
 648   "Take a char and return its value as if it was a hex digit."
 649   (if (and (>= character ?0) (<= character ?9))
 650       (- character ?0)
 651     (let ((ch (logior character 32)))
 652       (if (and (>= ch ?a) (<= ch ?f))
 653           (- ch (- ?a 10))
 654         (error "Invalid hex digit `%c'" ch)))))
 655
 656 (defun hexl-oct-char-to-integer (character)
 657   "Take a char and return its value as if it was a octal digit."
 658   (if (and (>= character ?0) (<= character ?7))
 659       (- character ?0)
 660     (error "Invalid octal digit `%c'" character)))
 661
 662 (defun hexl-printable-character (ch)
 663   "Return a displayable string for character CH."
 664   (format "%c" (if hexl-iso
 665                    (if (or (< ch 32) (and (>= ch 127) (< ch 160)))
 666                        46
 667                      ch)
 668                  (if (or (< ch 32) (>= ch 127))
 669                      46
 670                    ch))))
 671
 672 (defun hexl-self-insert-command (arg)
 673   "Insert this character."
 674   (interactive "p")
 675   (hexl-insert-char last-command-char arg))
 676
 677 (defun hexl-insert-char (ch num)
 678   "Insert a character in a hexl buffer."
 679   (let ((address (hexl-current-address t)))
 680     (while (> num 0)
 681       (let ((hex-position
 682              (+ (* (/ address 16) 68)
 683                 11
 684                 (* 2 (% address 16))
 685                 (/ (% address 16) 2)))
 686             (ascii-position
 687              (+ (* (/ address 16) 68) 52 (% address 16)))
 688             at-ascii-position)
 689         (if (= (point) ascii-position)
 690             (setq at-ascii-position t))
 691         (goto-char hex-position)
 692         (delete-char 2)
 693         (insert (format "%02x" ch))
 694         (goto-char ascii-position)
 695         (delete-char 1)
 696         (insert (hexl-printable-character ch))
 697         (or (eq address hexl-max-address)
 698             (setq address (1+ address)))
 699         (hexl-goto-address address)
 700         (if at-ascii-position
 701             (progn
 702               (beginning-of-line)
 703               (forward-char 51)
 704               (forward-char (% address 16)))))
 705       (setq num (1- num)))))
 706
 707 ;; hex conversion
 708
 709 (defun hexl-insert-hex-char (arg)
 710   "Insert a ASCII char ARG times at point for a given hexadecimal number."
 711   (interactive "p")
 712   (let ((num (hexl-hex-string-to-integer (read-string "Hex number: "))))
 713     (if (or (> num 255) (< num 0))
 714         (error "Hex number out of range")
 715       (hexl-insert-char num arg))))
 716
 717 (defun hexl-insert-decimal-char (arg)
 718   "Insert a ASCII char ARG times at point for a given decimal number."
 719   (interactive "p")
 720   (let ((num (string-to-int (read-string "Decimal Number: "))))
 721     (if (or (> num 255) (< num 0))
 722         (error "Decimal number out of range")
 723       (hexl-insert-char num arg))))
 724
 725 (defun hexl-insert-octal-char (arg)
 726   "Insert a ASCII char ARG times at point for a given octal number."
 727   (interactive "p")
 728   (let ((num (hexl-octal-string-to-integer (read-string "Octal Number: "))))
 729     (if (or (> num 255) (< num 0))
 730         (error "Decimal number out of range")
 731       (hexl-insert-char num arg))))
 732
 733 (defun hexl-follow-ascii (&optional arg)
 734   "Toggle following ASCII in Hexl buffers.
 735 With prefix ARG, turn on following if and only if ARG is positive.
 736 When following is enabled, the ASCII character corresponding to the
 737 element under the point is highlighted.
 738 Customize the variable `hexl-follow-ascii' to disable this feature."
 739   (interactive "P")
 740   (let ((on-p (if arg
 741                   (> (prefix-numeric-value arg) 0)
 742                (not hexl-ascii-overlay))))
 743
 744     (make-local-hook 'post-command-hook)
 745
 746     (if on-p
 747       ;; turn it on
 748       (if (not hexl-ascii-overlay)
 749           (progn
 750             (setq hexl-ascii-overlay (make-overlay 1 1)
 751                   hexl-follow-ascii t)
 752             (overlay-put hexl-ascii-overlay 'face 'highlight)
 753             (add-hook 'post-command-hook 'hexl-follow-ascii-find nil t)))
 754       ;; turn it off
 755       (if hexl-ascii-overlay
 756           (progn
 757             (delete-overlay hexl-ascii-overlay)
 758             (setq hexl-ascii-overlay nil
 759                   hexl-follow-ascii nil)
 760             (remove-hook 'post-command-hook 'hexl-follow-ascii-find t)
 761             )))))
 762
 763 (defun hexl-follow-ascii-find ()
 764   "Find and highlight the ASCII element corresponding to current point."
 765   (let ((pos (+ 51
 766                 (- (point) (current-column))
 767                 (mod (hexl-current-address) 16))))
 768     (move-overlay hexl-ascii-overlay pos (1+ pos))
 769     ))
 770
 771 ;; startup stuff.
 772
 773 (if hexl-mode-map
 774     nil
 775   (setq hexl-mode-map (make-sparse-keymap))
 776
 777   (define-key hexl-mode-map [left] 'hexl-backward-char)
 778   (define-key hexl-mode-map [right] 'hexl-forward-char)
 779   (define-key hexl-mode-map [up] 'hexl-previous-line)
 780   (define-key hexl-mode-map [down] 'hexl-next-line)
 781   (define-key hexl-mode-map [M-left] 'hexl-backward-short)
 782   (define-key hexl-mode-map [M-right] 'hexl-forward-short)
 783   (define-key hexl-mode-map [next] 'hexl-scroll-up)
 784   (define-key hexl-mode-map [prior] 'hexl-scroll-down)
 785   (define-key hexl-mode-map [home] 'hexl-beginning-of-buffer)
 786   (define-key hexl-mode-map [deletechar] 'undefined)
 787   (define-key hexl-mode-map [deleteline] 'undefined)
 788   (define-key hexl-mode-map [insertline] 'undefined)
 789   (define-key hexl-mode-map [S-delete] 'undefined)
 790   (define-key hexl-mode-map "\177" 'undefined)
 791
 792   (define-key hexl-mode-map "\C-a" 'hexl-beginning-of-line)
 793   (define-key hexl-mode-map "\C-b" 'hexl-backward-char)
 794   (define-key hexl-mode-map "\C-d" 'undefined)
 795   (define-key hexl-mode-map "\C-e" 'hexl-end-of-line)
 796   (define-key hexl-mode-map "\C-f" 'hexl-forward-char)
 797
 798   (if (not (eq (key-binding (char-to-string help-char)) 'help-command))
 799       (define-key hexl-mode-map (char-to-string help-char) 'undefined))
 800
 801   (define-key hexl-mode-map "\C-i" 'hexl-self-insert-command)
 802   (define-key hexl-mode-map "\C-j" 'hexl-self-insert-command)
 803   (define-key hexl-mode-map "\C-k" 'undefined)
 804   (define-key hexl-mode-map "\C-m" 'hexl-self-insert-command)
 805   (define-key hexl-mode-map "\C-n" 'hexl-next-line)
 806   (define-key hexl-mode-map "\C-o" 'undefined)
 807   (define-key hexl-mode-map "\C-p" 'hexl-previous-line)
 808   (define-key hexl-mode-map "\C-q" 'hexl-quoted-insert)
 809   (define-key hexl-mode-map "\C-t" 'undefined)
 810   (define-key hexl-mode-map "\C-v" 'hexl-scroll-up)
 811   (define-key hexl-mode-map "\C-w" 'undefined)
 812   (define-key hexl-mode-map "\C-y" 'undefined)
 813
 814   (let ((ch 32))
 815     (while (< ch 127)
 816       (define-key hexl-mode-map (format "%c" ch) 'hexl-self-insert-command)
 817       (setq ch (1+ ch))))
 818
 819   (define-key hexl-mode-map "\e\C-a" 'hexl-beginning-of-512b-page)
 820   (define-key hexl-mode-map "\e\C-b" 'hexl-backward-short)
 821   (define-key hexl-mode-map "\e\C-d" 'hexl-insert-decimal-char)
 822   (define-key hexl-mode-map "\e\C-e" 'hexl-end-of-512b-page)
 823   (define-key hexl-mode-map "\e\C-f" 'hexl-forward-short)
 824   (define-key hexl-mode-map "\e\C-i" 'undefined)
 825   (define-key hexl-mode-map "\e\C-j" 'undefined)
 826   (define-key hexl-mode-map "\e\C-k" 'undefined)
 827   (define-key hexl-mode-map "\e\C-o" 'hexl-insert-octal-char)
 828   (define-key hexl-mode-map "\e\C-q" 'undefined)
 829   (define-key hexl-mode-map "\e\C-t" 'undefined)
 830   (define-key hexl-mode-map "\e\C-x" 'hexl-insert-hex-char)
 831   (define-key hexl-mode-map "\eb" 'hexl-backward-word)
 832   (define-key hexl-mode-map "\ec" 'undefined)
 833   (define-key hexl-mode-map "\ed" 'undefined)
 834   (define-key hexl-mode-map "\ef" 'hexl-forward-word)
 835   (define-key hexl-mode-map "\eg" 'hexl-goto-hex-address)
 836   (define-key hexl-mode-map "\ei" 'undefined)
 837   (define-key hexl-mode-map "\ej" 'hexl-goto-address)
 838   (define-key hexl-mode-map "\ek" 'undefined)
 839   (define-key hexl-mode-map "\el" 'undefined)
 840   (define-key hexl-mode-map "\eq" 'undefined)
 841   (define-key hexl-mode-map "\es" 'undefined)
 842   (define-key hexl-mode-map "\et" 'undefined)
 843   (define-key hexl-mode-map "\eu" 'undefined)
 844   (define-key hexl-mode-map "\ev" 'hexl-scroll-down)
 845   (define-key hexl-mode-map "\ey" 'undefined)
 846   (define-key hexl-mode-map "\ez" 'undefined)
 847   (define-key hexl-mode-map "\e<" 'hexl-beginning-of-buffer)
 848   (define-key hexl-mode-map "\e>" 'hexl-end-of-buffer)
 849
 850   (define-key hexl-mode-map "\C-c\C-c" 'hexl-mode-exit)
 851
 852   (define-key hexl-mode-map "\C-x[" 'hexl-beginning-of-1k-page)
 853   (define-key hexl-mode-map "\C-x]" 'hexl-end-of-1k-page)
 854   (define-key hexl-mode-map "\C-x\C-p" 'undefined)
 855   (define-key hexl-mode-map "\C-x\C-s" 'hexl-save-buffer)
 856   (define-key hexl-mode-map "\C-x\C-t" 'undefined))
 857
 858 (provide 'hexl)
 859
 860 ;;; hexl.el ends here