by Richard E. Morris
918-437-3837 (24 hour BBS)
You can use a word processor or text editor to modify text files, but
neither of those programs can edit binary files. Files with extensions
such as .EXE and .COM, or other binary files such as graphics files,
simply won't load into a word processor.
HexEdit lets you load, view, and edit binary files of all kinds. It
includes many word processing features, such as search and replace,
making it one of the most powerful editors available.
Program files -- those with extensions .EXE and .COM -- must be
modified very carefully. Unless you're very familiar with binary
program files, use HexEdit only to change the ASCII portions of those
files. If you change other parts of the files, or alter their length,
chances are they won't run.
WHEN MODIFYING FILES, ALWAYS WORK WITH A COPY OF THE FILE, NEVER
WITH THE ORIGINAL FILE!
WHEN TO USE HEXEDIT
Those cautions aside, there are many uses for HexEdit. Programmers
can use it to fix spelling errors in a .COM or .EXE file without
recompiling the program. Database users can repair corrupted data
files. End users can use HexEdit to examine and alter programs and
other binary files.
You can also use the program to inspect binary files for messages
that may indicate that the file is a Trojan horse program. Most
of these programs contain some sort of message, like "Gotcha!" or "Now
Trashing Hard Disk."
Finally, it's just interesting to have the power to look inside files
you couldn't see before.
Install HexEdit by copying HEXEDIT.EXE onto your utility diskette or
into a directory on your hard disk. If you copy the program into a
directory named in the PATH statement in your AUTOEXEC.BAT file,
you'll be able to run it from any prompt. For more information about
the PATH statement, see your DOS manual.
Start the program with the command HEXEDIT . You'll see an
opening shareware screen. Press any key to proceed. You'll see a
list of HexEdit's commands. Press to load a file. You'll be
prompted for a filename.
Once a file is loaded, you'll see the editing screen. It's divided
into three columns. On the left are the relative addresses of the
file, in hexadecimal notation. The next column is the contents of the
file, also in hexadecimal. The far right column is the file in ASCII
Use the cursor keys to move around in the file. Edit by typing over
the characters you want to change. In normal use, you'll want to alter
characters in the ASCII column. Unless you know exactly what you're
doing, don't change the hexadecimal column.
Press -H at any time to view the command list.
- Delete a range of characters to the memory buffer. Before giving
this command, place the cursor on the first character of the block
you want to delete to the buffer. You'll be prompted to move the
cursor to the end of the block. Press to complete the deletion.
- - Delete range. Unlike the previous command, this
command removes the block of characters permanently. You'll be asked
to confirm this operation.
- Insert characters into file. If you give this command, you'll
be asked for the number of characters to insert. HexEdit will insert
that number of hexadecimal character 00, at the cursor location.
- - Insert contents of buffer. If you've deleted a block to
the buffer, this command will insert the buffer at the cursor
- Open a file for editing.
- - Insert a file before cursor. This command lets you
combine multiple files.
- Save file. You'll be prompted for a filename, with the current
file as a default.
- - Search backward. Before using this command, use
- to set the search text.
- Go to an address in the file. Enter the address in hexadecimal
- - Fill a range with a byte value. This command replaces
all characters in a block with the character you specify. You'll be
prompted for the replacement character, then asked to mark the end of
- Search forward. Use - to set the search text before
giving this command.
- - Set search string. Use this command before any search
or replace operation. You'll be asked whether you want to search for
hexadecimal or ASCII characters, then asked for the search characters.
HexEdit's search is case-sensitive, so searching for "Hello" won't
- Replace (must do search first). Use - to set the
replacement text before giving this command. Replaces one block at a
- - Set replace string. Works the same as -.
- Calculate 16-bit checksum of file.
- - Replace all. Set the search and replace strings before
giving this command.
- Copy range to buffer. Similar to , but does not delete the
- - Overwrite with buffer. If you have characters in the
buffer, this command overwrites the same number of characters, from
the cursor position.
- Close file. You'll be prompted to save the file.
- - Close file and exit the program. You'll be prompted to
save the file.
- Abort input of string. Also aborts the current command and
returns you to the editing screen.
- Move to beginning of file.
- Move to end of file.
Arrow Keys - Move around file.
and - Move around file in larger jumps.
-H - Display a list of commands.
- - Undo last change. (Replace All cannot be undone.)
-D - DOS Shell (secondary command processor). Allows a temporary
exit to DOS>. Type EXIT to return to HexEdit.
Many hours have gone into this program, and I would like to be able to
justify writing it by having you, the end user, help me financially.
This is the most powerful program I have seen of its type, and once you
become familiar with its various functions, I hope you will agree.
If you would like to contribute and become a registered owner, please
mail $10.00 to the following address:
Richard E. Morris
REM Software Inc.
12182 East 21 Court
Tulsa, Oklahoma 74129
I also have a BBS. Call (918)437-3837. (300 megs, 9600 baud, 20mhz 386)