HEXEDIT(1) HEXEDIT(1)
12 July 1998
NAME
hexedit - view and edit files in hexadecimal or in ASCII
SYNOPSIS
hexedit [-s | --sector] [-m | --maximize] [-l<n> | --linelength <n>]
[-h | --help] [filename]
DESCRIPTION
hexedit shows a file both in ASCII and in hexadecimal. The file can be
a device as the file is read a piece at a time. You can modify the
file and search through it.
OPTIONS
-s, --sector
Format the display to have entire sectors.
-m, --maximize
Try to maximize the display.
--color
Display colors. This feature is only available if your operating
system supports it.
-l<n>, --linelength <n>
Explicitly set the number of bytes to display per line to <n>.
-h, --help
Show the usage.
COMMANDS (quickly)
Moving
<, > : go to start/end of the file
Right: next character
Left: previous character
Down: next line
Up: previous line
Home: beginning of line
End: end of line
PUp: page forward
PDown: page backward
Miscellaneous
F2: save
F3: load file
F1: help
Ctrl-L: redraw
Ctrl-Z: suspend
Ctrl-X: save and exit
Ctrl-C: exit without saving
Tab: toggle hex/ascii
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12 July 1998
Return: go to
Backspace: undo previous character
Ctrl-U: undo all
Ctrl-S: search forward
Ctrl-R: search backward
Cut&Paste
Ctrl-Space: set mark
Esc-W: copy
Ctrl-Y: paste
Esc-Y: paste into a file
Esc-I: fill
COMMANDS (full and detailed)
o Right-Arrow, Left-Arrow, Down-Arrow, Up-Arrow - move the cursor.
o Ctrl+F, Ctrl+B, Ctrl+N, Ctrl+P - move the cursor.
o Ctrl+Right-Arrow, Ctrl+Left-Arrow, Ctrl+Down-Arrow, Ctrl+Up-Arrow -
move n times the cursor.
o Esc+Right-Arrow, Esc+Left-Arrow, Esc+Down-Arrow, Esc+Up-Arrow - move
n times the cursor.
o Esc+F, Esc+B, Esc+N, Esc+P - move n times the cursor.
o Home, Ctrl+A - go the beginning of the line.
o End, Ctrl+E - go to the end of the line.
o Page up, Esc+V, F5 - go up in the file by one page.
o Page down, Ctrl+V, F6 - go down in the file by one page.
o <, Esc+<, Esc+Home - go to the beginning of the file.
o >, Esc+>, Esc+End - go to the end of the file (for regular files
that have a size).
o Ctrl+Z - suspend hexedit.
o Ctrl+U, Ctrl+_, Ctrl+/ - undo all (forget the modifications).
o Ctrl+Q - read next input character and insert it (this is useful for
inserting control characters and bound keys).
o Tab, Ctrl+T - toggle between ASCII and hexadecimal.
o /, Ctrl+S - search forward (in ASCII or in hexadecimal, use TAB to
change).
o Ctrl+R - search backward.
o Ctrl+G, F4 - go to a position in the file.
o Return - go to a sector in the file if --sector is used, otherwise
go to a position in the file.
o Esc+L - display the page starting at the current cursor position.
o F2, Ctrl+W - save the modifications.
o F1, Esc+H - help (show the man page).
o Ctrl+O, F3 - open another file
o Ctrl+L - redisplay (refresh) the display (useful when your terminal
screws up).
o Backspace, Ctrl+H - undo the modifications made on the previous
byte.
o Esc+Ctrl+H - undo the modifications made on the previous bytes.
o Ctrl+Space, F9 - set mark where cursor is.
o Esc+W, Delete, F7 - copy selected region.
o Ctrl+Y, Insert, F8 - paste (yank) previously copied region.
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HEXEDIT(1) HEXEDIT(1)
12 July 1998
o Esc+Y, F11 - save previously copied region to a file.
o Esc+I, F12 - fill the selection with a string
o Esc+T - truncate the file at the current location
o Ctrl+C - unconditional quit (without saving).
o F10, Ctrl+X - quit.
For the Esc commands, it sometimes works to use Alt instead of Esc.
Funny things here (especially for froggies :) egrave = Alt+H ,
ccedilla = Alt+G, Alt+Y = ugrave.
Modeline
At the bottom of the display you have the modeline (copied from
emacs). As in emacs, you have the indications --, ** and %% meaning
unmodified, modified and read-only. Then you have the name of the file
you're currently editing. Next to it is the current position of the
cursor in the file followed by the total file size. The total file
size isn't quite correct for devices.
While in --sector mode, it shows the sector the cursor is in.
Editing
You can edit in ASCII or in hexadecimal. You can switch between the
two with Tab. When the file is read-only, you can't edit it. When
trying to edit a read-only file, a message "File is read-only" tells
you it is non-writable.
The modifications are shown in bold until they are saved. The
modeline indicates whether you have modified the file or not.
When editing in hexadecimal, only 0,1,...,9, a,b,...,f, A,B,...F are
legal. Other keys are unbound. The first time you hit an unbound key,
the help pops up. It won't pop again unless you call the help
directly (with F1).
When editing in ascii, you can find it difficult to enter characters
like / which are bound to a function. The solution is to use the
quoted insert function Ctrl+Q, the key after the quoted insert
function is not processed by hexedit (like emacs' quoted-insert, or
like the \ character in C).
Searching
You can search for a string in ASCII or in hexadecimal. You can switch
between the two with Tab. If the string is found, the cursor is moved
to the beginning of the matching location. If the search failed, a
message "not found" tells you so. You can cancel the search by
pressing a key.
The search in hexadecimal is a bit confusing. You must give a
hexadecimal string with an even number of characters. The search can
then be done byte by byte. If you want to search a long number (eg: a
32 bit number), you must know the internal representation of that
number (little/big endian problem) and give it the way it is in
memory. For example, on an Intel processor (little endian), you must
swap every bytes: 0x12345678 is written 0x78563412 in memory and
that's the string you must give to the search engine.
Before searching you are asked if you want to save the changes, if the
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HEXEDIT(1) HEXEDIT(1)
12 July 1998
file is edited.
For more sophisticated search, see Volker Schatz's patch at
<http://www.volkerschatz.com/unix/homebrew.html#hexedit>.
Selecting, copying, pasting, filling
First, select the part of the buffer you want to copy: start setting
the mark where you want. Then go to the end of the area you want to
copy (you can use the go to function and the search functions). Then
copy it. You can then paste the copied area in the current file or in
another file.
You can also fill the selected area with a string or a character:
start choosing the block you want to fill in (set mark then move to
the end of the block), and call the fill function (F12). hexedit ask
you the string you want to fill the block with.
The code is not tuned for huge filling as it keeps the modifications
in memory until you save them. That's why hexedit will warn you if you
try to fill in a big block.
When the mark is set, the selection is shown in reverse mode.
Be aware that the copied area contains the modifications done at the
time of the copy. But if you undo the modifications, it does not
change the content of the copy buffer. It seems obvious but it's worth
saying.
Scrolling
The scrolling is different whether you are in --sector mode or not. In
normal mode, the scrolling is line by line. In sector mode, the
scrolling is sector by sector. In both modes, you can force the
display to start at a given position using Esc+L.
SEE ALSO
od(1), hdump(1), hexdump(1), bpe(1), hexed(1), beav(1).
AUTHOR
Pixel (Pascal Rigaux) <pixel@rigaux.org>,
Home page is <http://rigaux.org/>.
UNRESTRICTIONS
hexedit is Open Source; anyone may redistribute copies of hexedit to
anyone under the terms stated in the GNU General Public License.
You can find hexedit at
<https://github.com/pixel/hexedit/archive/1.6.tar.gz>
TODO
Anything you think could be nice...
LIMITATIONS
There are problems with the curses library given with Redhat 5.0 that
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12 July 1998
make hexedit think the terminal is huge. The result is that hexedit is
not usable.
The shortcuts work on some machines, and not on others. That's why
there are many shortcuts for each function. The Ctrl+Arrows and the
Alt+. do not work work as they should most of the time. On SUNs, you
must do Ctrl+V-Ctrl+V instead of Ctrl+V (!); and the Alt key is the
diamond one.
While searching, it could be interesting to know which position the
search has reached. It's always nice to see something moving to help
waiting.
The hexadecimal search could be able to search modulo 4 bits instead
of 8 bits. Another feature could be to complete padd odd length
hexadecimal searches with zeros.
BUGS
I have an example where the display is completely screwed up. It seems
to be a bug in ncurses (or maybe in xterm and rxvt)?? Don't know if
it's me using ncurses badly or not... It seems to happen when hexedit
leaves only one space at the end of the lines... If anyone has a (or
the) solution, please tell me!
If you have any problem with the program (even a small one), please do
report it to me. Remarks of any kind are also welcome.
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