Provided by: dhex_0.69-4_amd64 bug


     dhex — hex editor with a diff mode


     dhex [-x]
     dhex [-h] [-v] [-g] [-k] [-ab -ad -ah -ao base address] [-f config-file] [-m marker-file]
          [-ob -od -oh -oo offset] [-r searchlog] [-sa -sab string (ascii)]
          [-sh -shb string (hex)] [-w searchlog] [file]
     dhex [-h] [-v] [-g] [-k] [-a1b -a1d -a1h -a1o base address 1]
          [-a2b -a2d -a2h -a2o base address 2] [-cb] [-cd upper-limit] [-cl] [-f config-file]
          [-m marker-file] [-o1b -o1d -o1h -o1o offset1] [-o2b -o2d -o2h -o2o offset2]
          [-r1 searchlog1] [-r2 searchlog2] [-s1a -s1ab -s1h -s1hb string (ascii/hex)]
          [-s2a -s2ab -s2h -s2hb string (ascii/hex)] [-w1 searchlog1] [-w2 searchlog2]
          [file1 file2]


     dhex is a hex editor. It can be used to alter individual bytes in large files. Since it is a
     text-mode program based on ncurses, it can run in numerous scenarios.  Its special feature
     is the diff mode: With it, the user has a visual tool for file comparison. This mode is
     invoked when dhex is called with two instead of one file as parameters.


     All the options are case-insensitive and can be given as either upper- or lowercase

     -ab -ad -ah -ao base address
                 After loading a file, every address gets a base address other than 0. With this,
                 it is easier to work on partial memory dumps. The base address can be given as a
                 binary one with [-ab] , as a decimal one with [-ad] , as a hexadecimal one with
                 [-ah] or an octal with [-ao].

     -a1b -a1d -a1h -a1o base address 1

     -a2b -a2d -a2h -a2o base address 2
                 For the diff mode, it is possible to set two different base addresses. Again, a
                 binary address can be given as [-a1b -a2b] , as decimal one with [-a1d -a2d] ,
                 as hexadecimal one with [-a1h -a2h] or an octal one with [-a1o -a2o].

                 This base address is calculated into the marker files as well as the searchlogs.

     -cb -cl     Diff mode only: The input files can be correlated from the command line with the
                 best -cb or longest -cl match. This is very slow.

     -cd upper-limit
                 Diff mode only: The input files can be correlated from the command line with the
                 minimum difference. To improve the correlation speed, an upper limit can be

     -f configfile
                 Usually, .dhexrc is being read from the invoker's home directory. With this
                 parameter, any other config file can be loaded. See dhexrc(5) for a description
                 of its file format.

     -g          Shows the license

     -x          Starts the hexcal

     -h          Shows the help screen

     -k          Starts the keyboard setup manually before any file is being loaded. This is very
                 helpful when calling dhex from an exotic terminal.

     -m markerfile
                 It is possible in dhex to set bookmarks and store them in a markerfile for later
                 use. With this parameter, the markerfile is being read at start time, making it
                 unnecessary to read them later through the gui. Their file format is described
                 in dhex_markers(5).

     -ob -od -oh -oo offset
                 After loading a file, the cursor is set to 0, and the first page of bytes is
                 being shown on the screen. With one of those parameters it is possible to start
                 at any other location in the file. The cursorposition could be given as a binary
                 number with [-ob] , as a decimal one with [-od] , as a hexadecimal one with
                 [-oh] or an octal with [-oo].

     -o1b -o1d -o1h -o1o offset1

     -o2b -o2d -o2h -o2o offset2
                 For the diff mode, it is possible to set two different cursorpositions at start
                 time. Again, the cursorpositions can be given as a binary number with [-o1b
                 -o2b] , as decimal one with [-o1d -o2d] , as hexadecimal one with [-o1h -o2h] or
                 an octal one with [-o1o -o2o].

                 This way, the first few bytes in a file can be skipped, and just the rest can be

     -r searchlog
                 When searching from the command line, the offsets are being read from this
                 searchlog. Its format is being described in dhex_searchlog(5).

     -r1 searchlog1

     -r2 searchlog2
                 When searching in two files simultaneously, the offsets can be read from two
                 different searchlogs.

     -sa -sab -sh -shb string
                 Instead of setting the cursor offset to an absolute value, it is possible to
                 search for a specific string from the command line. If there is an additional
                 [-ob -od -oh -oo offset] present, the search will start there. It is possible to
                 read and write search logs with [-r searchlog] and [-w searchlog] respectively.
                 With [-sa string] is being interpreted as ASCII.  [-sh string] interprets it as
                 hex. For backwards search, [-sab string] or [-shb string] can be applied.

     -s1a -s1ab -s1h -s1hb string1

     -s2a -s2ab -s2h -s2hb string2
                 In the diff mode, it is possible to search for two strings in two files

     -v          Prints out the version of dhex.

     -w searchlog
                 When searching from the command line, write the results into this searchlog and
                 quit. It is being written in the format described in dhex_searchlog(5.)

     -w1 searchlog1

     -w2 searchlog2
                 When searching in two files simultaneously, write the results from both searches
                 into those log files.


     Menus have hotkeys, they are being presented in a different color. To jump from one menu
     item to the next, the cursor keys or the TAB key can be used.

     Input fields can be closed by pressing ESC, ENTER, or any cursor key. Only pressing ESC will
     not save the changes made in there.

   The keyboard setup
     When running dhex for the first time, without any configfile present, or with the parameter
     -k, the first screen shown is that of the keyboard setup. In this screen, the program asks
     the user to press certain keys. Which are (in order) ESCAPE, F1, F2, F3, F4, F5, F6, F7, F8,
     also tells the user what it intends to do with those keys later. So the user can decide on
     any alternative he chooses.  If he does not want to bind a specific function to a certain
     key, he can simply press ESCAPE and skip to the next question.

     After pressing all the keys, the user can chose whether or not to write those keys into the
     config file.

   The main screen
     The main screen is broken down into three columns: The first column contains the offset
     within the file for the current line. The second column contains the bytes in the file in
     hex format. Finally, the third coumn contains the same bytes, but this time in ascii format.
     If a byte is not printable, it is being substituted with a '.'.  How many bytes are are
     being shown in a line depends on the width of the terminal. For example, if the terminal is
     80 characters wide, 16 bytes are being shown in each line.

     If no other [-o] or [-a] parameter was given at start time, the cursor is being set to
     offset 0. It is also being shown in the hex column. Here, it can be moved with the cursor
     keys. When entering a hexadecimal number, the file is being edited. The file can be edited
     in the ascii column as well, simply by pressing the TAB key (or whichever key was
     substituted for it in the keyboard setup). Pressing TAB again will return the cursor to the
     hex column. Pressing F9 (or its substitute) will undo the last of the changes. Changes are
     being shown in a different color.

     Editing is not possible in the diff mode. Here, pressing the cursor keys will move both
     files synchronously.

   The goto screen
     Pressing F1 (or its substitute) will open the Goto... screen. Here, it is possible to jump
     to a specific address directly, without the need of scrolling there with the cursor keys.
     The address can be entered in the 'To' field, either absolute or relative (to leap over a
     specified amount of bytes). An absolute address is being chosen by pressing '=', and a
     relative one by pressing '+' or '-', for a positive or negative leap respectively.
     Regardless of the addressing mode, it has to be entered as a hexadecimal number.

     It is also possible to set up to ten bookmarks in this screen: Pressing '0'...'9' will
     select one of them. Moving the cursor to "Set" and pressing ENTER will alter one of those
     book marks. The "Diff:" fields are showing the difference between the actual cursor position
     and the bookmark.

     Bookmarks can be stored and loaded, for this there are the "Save Markers" and "Load Markers"
     items on the bottom. Upon selecting one of them, the user is being prompted for a filename.
     It is possible to load a marker file at start time, by providing the [-m markerfile]
     parameter.  dhex_markers(5) describes the format of the marker files.

     Pressing F2 (or its substitute) will open the Search... screen. Here, a short string can be
     entered (either in hex, or in ascii). If no logfiles are being selected, the cursor will
     jump to the next occurrence of this search string upon selection of "Go". It can be chosen
     if the search is supposed to be conducted forward of backwards.

     To jump to the next occurrence, F3 (or its substitute) has to be pressed. To jump to the
     previous one, F4 has to be pressed. The search itself wraps at the edges of the file,
     meaning that when it reaches the end, it will start from the beginning and vice versa.

     Searchlogs are an advanced way of searching: Writing to the searchlog does not jump the
     cursor from one occurrence to the next. Instead, it will write the offsets of all of them
     into the logfile. Their format is described in dhex_searchlog(5).

     Reading from this searchlog means that the search does not cover the whole file: Only the
     addresses which have been provided in this file are being searched. Thus it is possible to
     search for specific changes. Like for example the number of lives stored in the save file of
     a game.  dhex_searchlog(5) describes the format of the searchlog.

     Pressing F5 (or its substitute) will open a small 64 bit calculator. This calculator is
     capable of not only performing arithmetic operations (+, -, *, /, modulo), but also logic
     ones. (and, or, xor, shift). There are three columns to enter numbers as hexadecimals,
     decimals or in binary format. Pressing 'x' will close this screen. Using the command line
     argument [-x] will start it from the commandline.

     When dhex(1) is running in diff mode, pressing F6 (or its substitute) will open the dialog
     for file correlation. This will try to find the optimal offset between the two files. There
     are three algorithms available for finding this offset: Searching for the best match (as
     many bytes as possible are the same), the longest match (as many consecutive bytes match as
     possible), or the minimum difference (as little differences between the bytes as possible).

     Even though it seems like the same at first, looking for the minimum difference is in fact
     faster. This can be improved even more, if the user sets an upper difference limit.

     Upon selecting Go, the program will search for the optimal offset. This will take some time.

   Saving and quitting
     Pressing F10 (or its substitute) will close dhex.  In case there have been changes made to
     the file, a save dialog opens up. Here, it is possible to select whether or not to write the
     changes back into the file.


     $HOME/.dhexrc: The default location of the config file. If the $HOME-variable is not set,
     its location has to be provided manually.


     Report bugs to <>.  Make sure to include DHEX somewhere in the subject.


     Written by Thomas Dettbarn


     dhexrc(5), dhex_markers(5), dhex_searchlog(5)