lisp/hexl.el

   1 ;;; hexl.el --- edit a file in a hex dump format using the hexl filter.
   2
   3 ;; Copyright (C) 1989, 1994 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
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; This package implements a major mode for editing binary files.  It uses
  28 ;; a program called hexl, supplied with the GNU Emacs distribution, that
  29 ;; can filter a binary into an editable format or from the format back into
  30 ;; binary.  For full instructions, invoke `hexl-mode' on an empty buffer and
  31 ;; do `M-x describe-mode'.
  32 ;;
  33 ;; This may be useful in your .emacs:
  34 ;;
  35 ;;      (autoload 'hexl-find-file "hexl"
  36 ;;        "Edit file FILENAME in hexl-mode." t)
  37 ;;
  38 ;;      (define-key global-map "\C-c\C-h" 'hexl-find-file)
  39 ;;
  40 ;; NOTE: Remember to change HEXL-PROGRAM or HEXL-OPTIONS if needed.
  41 ;;
  42 ;; Currently hexl only supports big endian hex output with 16 bit
  43 ;; grouping.
  44 ;;
  45 ;; -iso in `hexl-options' will allow iso characters to display in the
  46 ;; ASCII region of the screen (if your emacs supports this) instead of
  47 ;; changing them to dots.
  48
  49 ;;; Code:
  50
  51 ;;
  52 ;; vars here
  53 ;;
  54
  55 (defvar hexl-program "hexl"
  56   "The program that will hexlify and de-hexlify its stdin.
  57 `hexl-program' will always be concatenated with `hexl-options'
  58 and \"-de\" when dehexlfying a buffer.")
  59
  60 (defvar hexl-iso ""
  61   "If your emacs can handle ISO characters, this should be set to
  62 \"-iso\" otherwise it should be \"\".")
  63
  64 (defvar hexl-options (format "-hex %s" hexl-iso)
  65   "Options to hexl-program that suit your needs.")
  66
  67 (defvar hexlify-command
  68   (format "%s%s %s" exec-directory hexl-program hexl-options)
  69   "The command to use to hexlify a buffer.")
  70
  71 (defvar dehexlify-command
  72   (format "%s%s -de %s" exec-directory hexl-program hexl-options)
  73   "The command to use to unhexlify a buffer.")
  74
  75 (defvar hexl-max-address 0
  76   "Maximum offset into hexl buffer.")
  77
  78 (defvar hexl-mode-map nil)
  79
  80 (defvar hexl-mode-old-local-map)
  81 (defvar hexl-mode-old-mode-name)
  82 (defvar hexl-mode-old-major-mode)
  83
  84 ;; routines
  85
  86 ;;;###autoload
  87 (defun hexl-mode (&optional arg)
  88   "\\<hexl-mode-map>
  89 A major mode for editing binary files in hex dump format.
  90
  91 This function automatically converts a buffer into the hexl format
  92 using the function `hexlify-buffer'.
  93
  94 Each line in the buffer has an \"address\" (displayed in hexadecimal)
  95 representing the offset into the file that the characters on this line
  96 are at and 16 characters from the file (displayed as hexadecimal
  97 values grouped every 16 bits) and as their ASCII values.
  98
  99 If any of the characters (displayed as ASCII characters) are
 100 unprintable (control or meta characters) they will be replaced as
 101 periods.
 102
 103 If `hexl-mode' is invoked with an argument the buffer is assumed to be
 104 in hexl format.
 105
 106 A sample format:
 107
 108   HEX ADDR: 0001 0203 0405 0607 0809 0a0b 0c0d 0e0f     ASCII-TEXT
 109   --------  ---- ---- ---- ---- ---- ---- ---- ----  ----------------
 110   00000000: 5468 6973 2069 7320 6865 786c 2d6d 6f64  This is hexl-mod
 111   00000010: 652e 2020 4561 6368 206c 696e 6520 7265  e.  Each line re
 112   00000020: 7072 6573 656e 7473 2031 3620 6279 7465  presents 16 byte
 113   00000030: 7320 6173 2068 6578 6164 6563 696d 616c  s as hexadecimal
 114   00000040: 2041 5343 4949 0a61 6e64 2070 7269 6e74   ASCII.and print
 115   00000050: 6162 6c65 2041 5343 4949 2063 6861 7261  able ASCII chara
 116   00000060: 6374 6572 732e 2020 416e 7920 636f 6e74  cters.  Any cont
 117   00000070: 726f 6c20 6f72 206e 6f6e 2d41 5343 4949  rol or non-ASCII
 118   00000080: 2063 6861 7261 6374 6572 730a 6172 6520   characters.are
 119   00000090: 6469 7370 6c61 7965 6420 6173 2070 6572  displayed as per
 120   000000a0: 696f 6473 2069 6e20 7468 6520 7072 696e  iods in the prin
 121   000000b0: 7461 626c 6520 6368 6172 6163 7465 7220  table character
 122   000000c0: 7265 6769 6f6e 2e0a                      region..
 123
 124 Movement is as simple as movement in a normal emacs text buffer.  Most
 125 cursor movement bindings are the same (ie. Use \\[hexl-backward-char], \\[hexl-forward-char], \\[hexl-next-line], and \\[hexl-previous-line]
 126 to move the cursor left, right, down, and up).
 127
 128 Advanced cursor movement commands (ala \\[hexl-beginning-of-line], \\[hexl-end-of-line], \\[hexl-beginning-of-buffer], and \\[hexl-end-of-buffer]) are
 129 also supported.
 130
 131 There are several ways to change text in hexl mode:
 132
 133 ASCII characters (character between space (0x20) and tilde (0x7E)) are
 134 bound to self-insert so you can simply type the character and it will
 135 insert itself (actually overstrike) into the buffer.
 136
 137 \\[hexl-quoted-insert] followed by another keystroke allows you to insert the key even if
 138 it isn't bound to self-insert.  An octal number can be supplied in place
 139 of another key to insert the octal number's ASCII representation.
 140
 141 \\[hexl-insert-hex-char] will insert a given hexadecimal value (if it is between 0 and 0xFF)
 142 into the buffer at the current point.
 143
 144 \\[hexl-insert-octal-char] will insert a given octal value (if it is between 0 and 0377)
 145 into the buffer at the current point.
 146
 147 \\[hexl-insert-decimal-char] will insert a given decimal value (if it is between 0 and 255)
 148 into the buffer at the current point.
 149
 150 \\[hexl-mode-exit] will exit hexl-mode.
 151
 152 Note: saving the file with any of the usual Emacs commands
 153 will actually convert it back to binary format while saving.
 154
 155 You can use \\[hexl-find-file] to visit a file in hexl-mode.
 156
 157 \\[describe-bindings] for advanced commands."
 158   (interactive "p")
 159   (if (eq major-mode 'hexl-mode)
 160       (error "You are already in hexl mode.")
 161     (kill-all-local-variables)
 162     (make-local-variable 'hexl-mode-old-local-map)
 163     (setq hexl-mode-old-local-map (current-local-map))
 164     (use-local-map hexl-mode-map)
 165
 166     (make-local-variable 'hexl-mode-old-mode-name)
 167     (setq hexl-mode-old-mode-name mode-name)
 168     (setq mode-name "Hexl")
 169
 170     (make-local-variable 'hexl-mode-old-major-mode)
 171     (setq hexl-mode-old-major-mode major-mode)
 172     (setq major-mode 'hexl-mode)
 173
 174     (make-local-variable 'write-contents-hooks)
 175     (add-hook 'write-contents-hooks 'hexl-save-buffer)
 176
 177     (make-local-hook 'after-revert-hook)
 178     (add-hook 'after-revert-hook 'hexl-after-revert-hook nil t)
 179
 180     (make-local-variable 'hexl-max-address)
 181
 182     (make-local-variable 'change-major-mode-hook)
 183     (add-hook 'change-major-mode-hook 'hexl-maybe-dehexlify-buffer)
 184
 185     (make-local-variable 'require-final-newline)
 186     (setq require-final-newline nil)
 187
 188     (let ((modified (buffer-modified-p))
 189           (inhibit-read-only t)
 190           (original-point (1- (point))))
 191       (and (eobp) (not (bobp))
 192            (setq original-point (1- original-point)))
 193       (if (not (or (eq arg 1) (not arg)))
 194           ;; if no argument then we guess at hexl-max-address
 195           (setq hexl-max-address (+ (* (/ (1- (buffer-size)) 68) 16) 15))
 196         (setq hexl-max-address (1- (buffer-size)))
 197         (hexlify-buffer)
 198         (set-buffer-modified-p modified)
 199         (hexl-goto-address original-point)))))
 200
 201 (defun hexl-after-revert-hook ()
 202   (hexlify-buffer)
 203   (set-buffer-modified-p nil))
 204
 205 (defvar hexl-in-save-buffer nil)
 206
 207 (defun hexl-save-buffer ()
 208   "Save a hexl format buffer as binary in visited file if modified."
 209   (interactive)
 210   (if hexl-in-save-buffer nil
 211     (set-buffer-modified-p (if (buffer-modified-p)
 212                                (save-excursion
 213                                  (let ((buf (generate-new-buffer " hexl"))
 214                                        (name (buffer-name))
 215                                        (file-name (buffer-file-name))
 216                                        (start (point-min))
 217                                        (end (point-max))
 218                                        modified)
 219                                    (set-buffer buf)
 220                                    (insert-buffer-substring name start end)
 221                                    (set-buffer name)
 222                                    (dehexlify-buffer)
 223                                    ;; Prevent infinite recursion.
 224                                    (let ((hexl-in-save-buffer t)
 225                                          (buffer-file-type t)) ; for ms-dos
 226                                      (save-buffer))
 227                                    (setq modified (buffer-modified-p))
 228                                    (delete-region (point-min) (point-max))
 229                                    (insert-buffer-substring buf start end)
 230                                    (kill-buffer buf)
 231                                    modified))
 232                              (message "(No changes need to be saved)")
 233                              nil))
 234     ;; Return t to indicate we have saved t
 235     t))
 236
 237 ;;;###autoload
 238 (defun hexl-find-file (filename)
 239   "Edit file FILENAME in hexl-mode.
 240 Switch to a buffer visiting file FILENAME, creating one in none exists."
 241   (interactive "fFilename: ")
 242   (if (or (eq system-type 'ms-dos) (eq system-type 'windows-nt))
 243       (find-file-binary filename)
 244     (find-file filename))
 245   (if (not (eq major-mode 'hexl-mode))
 246       (hexl-mode)))
 247
 248 (defun hexl-mode-exit (&optional arg)
 249   "Exit Hexl mode, returning to previous mode.
 250 With arg, don't unhexlify buffer."
 251   (interactive "p")
 252   (if (or (eq arg 1) (not arg))
 253       (let ((modified (buffer-modified-p))
 254             (inhibit-read-only t)
 255             (original-point (1+ (hexl-current-address))))
 256         (dehexlify-buffer)
 257         (remove-hook 'write-contents-hook 'hexl-save-buffer)
 258         (set-buffer-modified-p modified)
 259         (goto-char original-point)))
 260   (setq mode-name hexl-mode-old-mode-name)
 261   (use-local-map hexl-mode-old-local-map)
 262   (setq major-mode hexl-mode-old-major-mode)
 263   (force-mode-line-update))
 264
 265 (defun hexl-maybe-dehexlify-buffer ()
 266   "Convert a hexl format buffer to binary.
 267 Ask the user for confirmation."
 268   (if (y-or-n-p "Convert contents back to binary format? ")
 269       (let ((modified (buffer-modified-p))
 270             (inhibit-read-only t)
 271             (original-point (1+ (hexl-current-address))))
 272         (dehexlify-buffer)
 273         (remove-hook 'write-contents-hook 'hexl-save-buffer)
 274         (set-buffer-modified-p modified)
 275         (goto-char original-point))))
 276
 277 (defun hexl-current-address (&optional validate)
 278   "Return current hexl-address."
 279   (interactive)
 280   (let ((current-column (- (% (point) 68) 11))
 281         (hexl-address 0))
 282     (if (< current-column 0)
 283         (if validate
 284             (error "Point is not on a character in the file")
 285           (setq current-column 0)))
 286     (setq hexl-address
 287           (+ (* (/ (point) 68) 16)
 288              (if (>= current-column 41)
 289                  (- current-column 41)
 290                (/ (- current-column  (/ current-column 5)) 2))))
 291     hexl-address))
 292
 293 (defun hexl-address-to-marker (address)
 294   "Return marker for ADDRESS."
 295   (interactive "nAddress: ")
 296   (+ (* (/ address 16) 68) 11 (/ (* (% address 16) 5) 2)))
 297
 298 (defun hexl-goto-address (address)
 299   "Goto hexl-mode (decimal) address ADDRESS.
 300 Signal error if ADDRESS out of range."
 301   (interactive "nAddress: ")
 302   (if (or (< address 0) (> address hexl-max-address))
 303           (error "Out of hexl region."))
 304   (goto-char (hexl-address-to-marker address)))
 305
 306 (defun hexl-goto-hex-address (hex-address)
 307   "Go to hexl-mode address (hex string) HEX-ADDRESS.
 308 Signal error if HEX-ADDRESS is out of range."
 309   (interactive "sHex Address: ")
 310   (hexl-goto-address (hexl-hex-string-to-integer hex-address)))
 311
 312 (defun hexl-hex-string-to-integer (hex-string)
 313   "Return decimal integer for HEX-STRING."
 314   (interactive "sHex number: ")
 315   (let ((hex-num 0))
 316     (while (not (equal hex-string ""))
 317       (setq hex-num (+ (* hex-num 16)
 318                        (hexl-hex-char-to-integer (string-to-char hex-string))))
 319       (setq hex-string (substring hex-string 1)))
 320     hex-num))
 321
 322 (defun hexl-octal-string-to-integer (octal-string)
 323   "Return decimal integer for OCTAL-STRING."
 324   (interactive "sOctal number: ")
 325   (let ((oct-num 0))
 326     (while (not (equal octal-string ""))
 327       (setq oct-num (+ (* oct-num 8)
 328                        (hexl-oct-char-to-integer
 329                         (string-to-char octal-string))))
 330       (setq octal-string (substring octal-string 1)))
 331     oct-num))
 332
 333 ;; move point functions
 334
 335 (defun hexl-backward-char (arg)
 336   "Move to left ARG bytes (right if ARG negative) in hexl-mode."
 337   (interactive "p")
 338   (hexl-goto-address (- (hexl-current-address) arg)))
 339
 340 (defun hexl-forward-char (arg)
 341   "Move right ARG bytes (left if ARG negative) in hexl-mode."
 342   (interactive "p")
 343   (hexl-goto-address (+ (hexl-current-address) arg)))
 344
 345 (defun hexl-backward-short (arg)
 346   "Move to left ARG shorts (right if ARG negative) in hexl-mode."
 347   (interactive "p")
 348   (hexl-goto-address (let ((address (hexl-current-address)))
 349                        (if (< arg 0)
 350                            (progn
 351                              (setq arg (- arg))
 352                              (while (> arg 0)
 353                                (if (not (equal address (logior address 3)))
 354                                    (if (> address hexl-max-address)
 355                                        (progn
 356                                          (message "End of buffer.")
 357                                          (setq address hexl-max-address))
 358                                      (setq address (logior address 3)))
 359                                  (if (> address hexl-max-address)
 360                                      (progn
 361                                        (message "End of buffer.")
 362                                        (setq address hexl-max-address))
 363                                    (setq address (+ address 4))))
 364                                (setq arg (1- arg)))
 365                              (if (> address hexl-max-address)
 366                                  (progn
 367                                    (message "End of buffer.")
 368                                    (setq address hexl-max-address))
 369                                (setq address (logior address 3))))
 370                          (while (> arg 0)
 371                            (if (not (equal address (logand address -4)))
 372                                (setq address (logand address -4))
 373                              (if (not (equal address 0))
 374                                  (setq address (- address 4))
 375                                (message "Beginning of buffer.")))
 376                            (setq arg (1- arg))))
 377                        address)))
 378
 379 (defun hexl-forward-short (arg)
 380   "Move right ARG shorts (left if ARG negative) in hexl-mode."
 381   (interactive "p")
 382   (hexl-backward-short (- arg)))
 383
 384 (defun hexl-backward-word (arg)
 385   "Move to left ARG words (right if ARG negative) in hexl-mode."
 386   (interactive "p")
 387   (hexl-goto-address (let ((address (hexl-current-address)))
 388                        (if (< arg 0)
 389                            (progn
 390                              (setq arg (- arg))
 391                              (while (> arg 0)
 392                                (if (not (equal address (logior address 7)))
 393                                    (if (> address hexl-max-address)
 394                                        (progn
 395                                          (message "End of buffer.")
 396                                          (setq address hexl-max-address))
 397                                      (setq address (logior address 7)))
 398                                  (if (> address hexl-max-address)
 399                                      (progn
 400                                        (message "End of buffer.")
 401                                        (setq address hexl-max-address))
 402                                    (setq address (+ address 8))))
 403                                (setq arg (1- arg)))
 404                              (if (> address hexl-max-address)
 405                                  (progn
 406                                    (message "End of buffer.")
 407                                    (setq address hexl-max-address))
 408                                (setq address (logior address 7))))
 409                          (while (> arg 0)
 410                            (if (not (equal address (logand address -8)))
 411                                (setq address (logand address -8))
 412                              (if (not (equal address 0))
 413                                  (setq address (- address 8))
 414                                (message "Beginning of buffer.")))
 415                            (setq arg (1- arg))))
 416                        address)))
 417
 418 (defun hexl-forward-word (arg)
 419   "Move right ARG words (left if ARG negative) in hexl-mode."
 420   (interactive "p")
 421   (hexl-backward-word (- arg)))
 422
 423 (defun hexl-previous-line (arg)
 424   "Move vertically up ARG lines [16 bytes] (down if ARG negative) in hexl-mode.
 425 If there is byte at the target address move to the last byte in that line."
 426   (interactive "p")
 427   (hexl-next-line (- arg)))
 428
 429 (defun hexl-next-line (arg)
 430   "Move vertically down ARG lines [16 bytes] (up if ARG negative) in hexl-mode.
 431 If there is no byte at the target address move to the last byte in that line."
 432   (interactive "p")
 433   (hexl-goto-address (let ((address (+ (hexl-current-address) (* arg 16))))
 434                        (if (and (< arg 0) (< address 0))
 435                                 (progn (message "Out of hexl region.")
 436                                        (setq address
 437                                              (% (hexl-current-address) 16)))
 438                          (if (and (> address hexl-max-address)
 439                                   (< (% hexl-max-address 16) (% address 16)))
 440                              (setq address hexl-max-address)
 441                            (if (> address hexl-max-address)
 442                                (progn (message "Out of hexl region.")
 443                                       (setq
 444                                        address
 445                                        (+ (logand hexl-max-address -16)
 446                                           (% (hexl-current-address) 16)))))))
 447                        address)))
 448
 449 (defun hexl-beginning-of-buffer (arg)
 450   "Move to the beginning of the hexl buffer.
 451 Leaves `hexl-mark' at previous position.
 452 With prefix arg N, puts point N bytes of the way from the true beginning."
 453   (interactive "p")
 454   (push-mark (point))
 455   (hexl-goto-address (+ 0 (1- arg))))
 456
 457 (defun hexl-end-of-buffer (arg)
 458   "Go to `hexl-max-address' minus ARG."
 459   (interactive "p")
 460   (push-mark (point))
 461   (hexl-goto-address (- hexl-max-address (1- arg))))
 462
 463 (defun hexl-beginning-of-line ()
 464   "Goto beginning of line in hexl mode."
 465   (interactive)
 466   (goto-char (+ (* (/ (point) 68) 68) 11)))
 467
 468 (defun hexl-end-of-line ()
 469   "Goto end of line in hexl mode."
 470   (interactive)
 471   (hexl-goto-address (let ((address (logior (hexl-current-address) 15)))
 472                        (if (> address hexl-max-address)
 473                            (setq address hexl-max-address))
 474                        address)))
 475
 476 (defun hexl-scroll-down (arg)
 477   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG."
 478   (interactive "P")
 479   (if (null arg)
 480       (setq arg (1- (window-height)))
 481     (setq arg (prefix-numeric-value arg)))
 482   (hexl-scroll-up (- arg)))
 483
 484 (defun hexl-scroll-up (arg)
 485   "Scroll hexl buffer window upward ARG lines; or near full window if no ARG."
 486   (interactive "P")
 487   (if (null arg)
 488       (setq arg (1- (window-height)))
 489     (setq arg (prefix-numeric-value arg)))
 490   (let ((movement (* arg 16))
 491         (address (hexl-current-address)))
 492     (if (or (> (+ address movement) hexl-max-address)
 493             (< (+ address movement) 0))
 494         (message "Out of hexl region.")
 495       (hexl-goto-address (+ address movement))
 496       (recenter 0))))
 497
 498 (defun hexl-beginning-of-1k-page ()
 499   "Goto to beginning of 1k boundry."
 500   (interactive)
 501   (hexl-goto-address (logand (hexl-current-address) -1024)))
 502
 503 (defun hexl-end-of-1k-page ()
 504   "Goto to end of 1k boundry."
 505   (interactive)
 506   (hexl-goto-address (let ((address (logior (hexl-current-address) 1023)))
 507                        (if (> address hexl-max-address)
 508                            (setq address hexl-max-address))
 509                        address)))
 510
 511 (defun hexl-beginning-of-512b-page ()
 512   "Goto to beginning of 512 byte boundry."
 513   (interactive)
 514   (hexl-goto-address (logand (hexl-current-address) -512)))
 515
 516 (defun hexl-end-of-512b-page ()
 517   "Goto to end of 512 byte boundry."
 518   (interactive)
 519   (hexl-goto-address (let ((address (logior (hexl-current-address) 511)))
 520                        (if (> address hexl-max-address)
 521                            (setq address hexl-max-address))
 522                        address)))
 523
 524 (defun hexl-quoted-insert (arg)
 525   "Read next input character and insert it.
 526 Useful for inserting control characters.
 527 You may also type up to 3 octal digits, to insert a character with that code"
 528   (interactive "p")
 529   (hexl-insert-char (read-quoted-char) arg))
 530
 531 ;00000000: 0011 2233 4455 6677 8899 aabb ccdd eeff  0123456789ABCDEF
 532
 533 ;;;###autoload
 534 (defun hexlify-buffer ()
 535   "Convert a binary buffer to hexl format."
 536   (interactive)
 537   (let ((binary-process-output nil) ; for Ms-Dos
 538         (binary-process-input t))
 539     (shell-command-on-region (point-min) (point-max) hexlify-command t)))
 540
 541 (defun dehexlify-buffer ()
 542   "Convert a hexl format buffer to binary."
 543   (interactive)
 544   (let ((binary-process-output t) ; for Ms-Dos
 545         (binary-process-input nil))
 546     (shell-command-on-region (point-min) (point-max) dehexlify-command t)))
 547
 548 (defun hexl-char-after-point ()
 549   "Return char for ASCII hex digits at point."
 550   (hexl-htoi (char-after (point))
 551              (char-after (1+ (point)))))
 552
 553 (defun hexl-htoi (lh rh)
 554   "Hex (char) LH (char) RH to integer."
 555     (+ (* (hexl-hex-char-to-integer lh) 16)
 556        (hexl-hex-char-to-integer rh)))
 557
 558 (defun hexl-hex-char-to-integer (character)
 559   "Take a char and return its value as if it was a hex digit."
 560   (if (and (>= character ?0) (<= character ?9))
 561       (- character ?0)
 562     (let ((ch (logior character 32)))
 563       (if (and (>= ch ?a) (<= ch ?f))
 564           (- ch (- ?a 10))
 565         (error (format "Invalid hex digit `%c'." ch))))))
 566
 567 (defun hexl-oct-char-to-integer (character)
 568   "Take a char and return its value as if it was a octal digit."
 569   (if (and (>= character ?0) (<= character ?7))
 570       (- character ?0)
 571     (error (format "Invalid octal digit `%c'." character))))
 572
 573 (defun hexl-printable-character (ch)
 574   "Return a displayable string for character CH."
 575   (format "%c" (if hexl-iso
 576                    (if (or (< ch 32) (and (>= ch 127) (< ch 160)))
 577                        46
 578                      ch)
 579                  (if (or (< ch 32) (>= ch 127))
 580                      46
 581                    ch))))
 582
 583 (defun hexl-self-insert-command (arg)
 584   "Insert this character."
 585   (interactive "p")
 586   (hexl-insert-char last-command-char arg))
 587
 588 (defun hexl-insert-char (ch num)
 589   "Insert a character in a hexl buffer."
 590   (let ((address (hexl-current-address t)))
 591     (while (> num 0)
 592       (let ((hex-position
 593              (+ (* (/ address 16) 68)
 594                 11
 595                 (* 2 (% address 16))
 596                 (/ (% address 16) 2)))
 597             (ascii-position
 598              (+ (* (/ address 16) 68) 52 (% address 16)))
 599             at-ascii-position)
 600         (if (= (point) ascii-position)
 601             (setq at-ascii-position t))
 602         (goto-char hex-position)
 603         (delete-char 2)
 604         (insert (format "%02x" ch))
 605         (goto-char ascii-position)
 606         (delete-char 1)
 607         (insert (hexl-printable-character ch))
 608         (or (eq address hexl-max-address)
 609             (setq address (1+ address)))
 610         (hexl-goto-address address)
 611         (if at-ascii-position
 612             (progn
 613               (beginning-of-line)
 614               (forward-char 51)
 615               (forward-char (% address 16)))))
 616       (setq num (1- num)))))
 617
 618 ;; hex conversion
 619
 620 (defun hexl-insert-hex-char (arg)
 621   "Insert a ASCII char ARG times at point for a given hexadecimal number."
 622   (interactive "p")
 623   (let ((num (hexl-hex-string-to-integer (read-string "Hex number: "))))
 624     (if (or (> num 255) (< num 0))
 625         (error "Hex number out of range.")
 626       (hexl-insert-char num arg))))
 627
 628 (defun hexl-insert-decimal-char (arg)
 629   "Insert a ASCII char ARG times at point for a given decimal number."
 630   (interactive "p")
 631   (let ((num (string-to-int (read-string "Decimal Number: "))))
 632     (if (or (> num 255) (< num 0))
 633         (error "Decimal number out of range.")
 634       (hexl-insert-char num arg))))
 635
 636 (defun hexl-insert-octal-char (arg)
 637   "Insert a ASCII char ARG times at point for a given octal number."
 638   (interactive "p")
 639   (let ((num (hexl-octal-string-to-integer (read-string "Octal Number: "))))
 640     (if (or (> num 255) (< num 0))
 641         (error "Decimal number out of range.")
 642       (hexl-insert-char num arg))))
 643
 644 ;; startup stuff.
 645
 646 (if hexl-mode-map
 647     nil
 648     (setq hexl-mode-map (make-sparse-keymap))
 649
 650     (define-key hexl-mode-map [left] 'hexl-backward-char)
 651     (define-key hexl-mode-map [right] 'hexl-forward-char)
 652     (define-key hexl-mode-map [up] 'hexl-previous-line)
 653     (define-key hexl-mode-map [down] 'hexl-next-line)
 654     (define-key hexl-mode-map [M-left] 'hexl-backward-short)
 655     (define-key hexl-mode-map [M-right] 'hexl-forward-short)
 656     (define-key hexl-mode-map [next] 'hexl-scroll-up)
 657     (define-key hexl-mode-map [prev] 'hexl-scroll-down)
 658
 659     (define-key hexl-mode-map "\C-a" 'hexl-beginning-of-line)
 660     (define-key hexl-mode-map "\C-b" 'hexl-backward-char)
 661     (define-key hexl-mode-map "\C-d" 'undefined)
 662     (define-key hexl-mode-map "\C-e" 'hexl-end-of-line)
 663     (define-key hexl-mode-map "\C-f" 'hexl-forward-char)
 664
 665     (if (not (eq (key-binding (char-to-string help-char)) 'help-command))
 666         (define-key hexl-mode-map (char-to-string help-char) 'undefined))
 667
 668     (define-key hexl-mode-map "\C-i" 'hexl-self-insert-command)
 669     (define-key hexl-mode-map "\C-j" 'hexl-self-insert-command)
 670     (define-key hexl-mode-map "\C-k" 'undefined)
 671     (define-key hexl-mode-map "\C-m" 'hexl-self-insert-command)
 672     (define-key hexl-mode-map "\C-n" 'hexl-next-line)
 673     (define-key hexl-mode-map "\C-o" 'undefined)
 674     (define-key hexl-mode-map "\C-p" 'hexl-previous-line)
 675     (define-key hexl-mode-map "\C-q" 'hexl-quoted-insert)
 676     (define-key hexl-mode-map "\C-t" 'undefined)
 677     (define-key hexl-mode-map "\C-v" 'hexl-scroll-up)
 678     (define-key hexl-mode-map "\C-w" 'undefined)
 679     (define-key hexl-mode-map "\C-y" 'undefined)
 680
 681     (let ((ch 32))
 682       (while (< ch 127)
 683         (define-key hexl-mode-map (format "%c" ch) 'hexl-self-insert-command)
 684         (setq ch (1+ ch))))
 685
 686     (define-key hexl-mode-map "\e\C-a" 'hexl-beginning-of-512b-page)
 687     (define-key hexl-mode-map "\e\C-b" 'hexl-backward-short)
 688     (define-key hexl-mode-map "\e\C-c" 'undefined)
 689     (define-key hexl-mode-map "\e\C-d" 'hexl-insert-decimal-char)
 690     (define-key hexl-mode-map "\e\C-e" 'hexl-end-of-512b-page)
 691     (define-key hexl-mode-map "\e\C-f" 'hexl-forward-short)
 692     (define-key hexl-mode-map "\e\C-g" 'undefined)
 693     (define-key hexl-mode-map "\e\C-h" 'undefined)
 694     (define-key hexl-mode-map "\e\C-i" 'undefined)
 695     (define-key hexl-mode-map "\e\C-j" 'undefined)
 696     (define-key hexl-mode-map "\e\C-k" 'undefined)
 697     (define-key hexl-mode-map "\e\C-l" 'undefined)
 698     (define-key hexl-mode-map "\e\C-m" 'undefined)
 699     (define-key hexl-mode-map "\e\C-n" 'undefined)
 700     (define-key hexl-mode-map "\e\C-o" 'hexl-insert-octal-char)
 701     (define-key hexl-mode-map "\e\C-p" 'undefined)
 702     (define-key hexl-mode-map "\e\C-q" 'undefined)
 703     (define-key hexl-mode-map "\e\C-r" 'undefined)
 704     (define-key hexl-mode-map "\e\C-s" 'undefined)
 705     (define-key hexl-mode-map "\e\C-t" 'undefined)
 706     (define-key hexl-mode-map "\e\C-u" 'undefined)
 707
 708     (define-key hexl-mode-map "\e\C-w" 'undefined)
 709     (define-key hexl-mode-map "\e\C-x" 'hexl-insert-hex-char)
 710     (define-key hexl-mode-map "\e\C-y" 'undefined)
 711
 712     (define-key hexl-mode-map "\ea" 'undefined)
 713     (define-key hexl-mode-map "\eb" 'hexl-backward-word)
 714     (define-key hexl-mode-map "\ec" 'undefined)
 715     (define-key hexl-mode-map "\ed" 'undefined)
 716     (define-key hexl-mode-map "\ee" 'undefined)
 717     (define-key hexl-mode-map "\ef" 'hexl-forward-word)
 718     (define-key hexl-mode-map "\eg" 'hexl-goto-hex-address)
 719     (define-key hexl-mode-map "\eh" 'undefined)
 720     (define-key hexl-mode-map "\ei" 'undefined)
 721     (define-key hexl-mode-map "\ej" 'hexl-goto-address)
 722     (define-key hexl-mode-map "\ek" 'undefined)
 723     (define-key hexl-mode-map "\el" 'undefined)
 724     (define-key hexl-mode-map "\em" 'undefined)
 725     (define-key hexl-mode-map "\en" 'undefined)
 726     (define-key hexl-mode-map "\eo" 'undefined)
 727     (define-key hexl-mode-map "\ep" 'undefined)
 728     (define-key hexl-mode-map "\eq" 'undefined)
 729     (define-key hexl-mode-map "\er" 'undefined)
 730     (define-key hexl-mode-map "\es" 'undefined)
 731     (define-key hexl-mode-map "\et" 'undefined)
 732     (define-key hexl-mode-map "\eu" 'undefined)
 733     (define-key hexl-mode-map "\ev" 'hexl-scroll-down)
 734     (define-key hexl-mode-map "\ey" 'undefined)
 735     (define-key hexl-mode-map "\ez" 'undefined)
 736     (define-key hexl-mode-map "\e<" 'hexl-beginning-of-buffer)
 737     (define-key hexl-mode-map "\e>" 'hexl-end-of-buffer)
 738
 739     (define-key hexl-mode-map "\C-c\C-c" 'hexl-mode-exit)
 740
 741     (define-key hexl-mode-map "\C-x[" 'hexl-beginning-of-1k-page)
 742     (define-key hexl-mode-map "\C-x]" 'hexl-end-of-1k-page)
 743     (define-key hexl-mode-map "\C-x\C-p" 'undefined)
 744     (define-key hexl-mode-map "\C-x\C-s" 'hexl-save-buffer)
 745     (define-key hexl-mode-map "\C-x\C-t" 'undefined))
 746
 747 ;;; hexl.el ends here