This is HT 2.0.22; Have fun…
| • About: | ||
| • Key bindings: | ||
| • Features: | ||
| • Authors: | ||
| • Where to download?: |
This program is a file viewer, editor and analyzer for text, binary, and (especially) executable files.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
| Return | follow link (if applicable) |
| Backspace | undo “follow link” |
| Space/F6 | choose view mode |
| Alt+[1-9] | select window |
| Alt+0 | select window list |
| Ctrl+Left/Right | scroll left/right |
| Cursor keys | move around |
| Page Up/Down | next/prev page |
| Alt+S | toggle select |
| Ctrl+Ins/Alt+C | copy |
| Shift+Ins/Alt+V | insert |
| Ctrl+Del/Alt+D | delete |
| Shift+Del/Alt+X | cut |
| Alt+F3/Ctrl+W | close window |
| Ctrl+F5 | resize/move mode |
| (in resize/move mode only:) | |
| Space | toggle resize/move mode |
| Cursor keys | resize/move window |
| Escape/Return/Ctrl+F5 | leave resize/move mode |
| c | continue code analysis at cursor |
| f | follow dword ptr at address |
| n | name current address (empty string to delete) |
| x | show xrefs (search for xrefs) |
| # | edit comments |
| s | define a string |
| i | define an integer (32bit) |
| h | define a halfword (16bit) |
| b | define a byte (8bit) |
| Ctrl+A | call assembler |
| Ctrl+F | goto start of current function (indicated in the 2nd line) |
| Ctrl+L | goto previous label |
| Ctrl+T | show recursive function references |
Note: Some keys don’t work in HT-posix. Try using Escape instead of Control or something...
HT contains some very advanced and useful features, which you should carefully inspect:
| • General features: | ||
| • Configuration files: | ||
| • Clipboard: | ||
| • Global history: | ||
| • Expression evaluation: | ||
| • Block operations: | ||
| • Search and its different modes: | ||
| • Command line options: |
HT automatically creates a file to store its configuration. It is called ~/.htcfg2 on Unices and ht.cfg2 (where ht.exe resides) on Windows. More specifically it contains HT’s registry and the See Global history.
The analyser (for analysable files) will be stored in an extra file called FILENAME.htcfg, where FILENAME is the analysed file. This file contains all information to restore the complete state of the analyser.
All open files and dialogs use the common clipboard, where all copied and cut text or binary data is stored. Clipboard operations are normally binary safe, that means you can copy some binary data out of a file and paste it into an input line. Exceptions are only the \0 character (binary null), it will be converted to a space in places where it would not make sense (e.g. file open).
Although the clipboard won’t be saved between different HT sessions (ie. you will loose it when exiting HT), you can either save and load it or part of it manually (via Edit->paste into/copy from file) or rely on the input lines’ See history, which is stored and retrieved from the config file automatically.
HTs history system is global, which means that you can use it for all open files. Histories are also grouped by their context. I.e. file-related and regex-search-related dialogs have their own history (who would want to open "[0-9][0-9a-z]+" anyway?).
History entries are stored within the See Configuration files, so they can be reused when you relaunch.
You can delete a history entry by pressing DEL inside the history popup.
HT contains a very powerful expression evaluator which is used in all dialogs where expressions are expected. These are mainly blockoperation, goto, search and of course evaluate itself (Edit->Evaluate).
You can use all standard math operators (+ - / * % **), logical operators (! && || ^^), relational operators (== != < > <= >=), bit operators (~ & | ^), string operators (. for concatenation), parenthesis, the ternary operator (a?b:c), functions and symbols (both depending on context).
The evaluator uses integer, string and float types depending on context. You
can always convert a result via the int(), string() and float() functions
to appropriate type. Try Edit->Evaluate to see how it works…
You can always use the standard built-in math (round, sin, random, etc.) and
string (strcmp, strchr, sprintf, etc.) functions, they work more or less like the corresponding
C functions (actually they ARE more or less wrappers for them); see eval/eval.y for
details (sorry but a detailed help would get outdated rather soon).
The symbol _ always refers to the last result.
If you are in a hex buffer, the variable first contains the offset of the first byte and the variable
last contains the offset of the last byte. This is useful, for instace, if you want to jump to the last byte of a file.
If you are in a hex buffer, the variable first contains the offset of the first byte and the variable
last contains the offset of the last byte. This is useful, for instance, if you want to jump to the last byte of a file.
When using See Block operations, or searching you have some context depending functions and symbols; see these sections for explanation.
Block operation (Blockop) is a very powerful tool to perform modifications on binary files. It is available in hex viewer only.
Blockop takes four parameters: start, end, mode and expression. Blockop works as follows:
Special variables/functions that can be used in expression:
readbyte(ofs)read a byte from offset ofs, returns a number
readstring(ofs, size)read size bytes from offset ofs, returns a string
icontains the iteration count/index starting with 0
The search function is one of the most advanced functions of HT. It is invoked through F7, Shift-F7 continues a search from cursor. Depending on context (ie. file type and mode) the following modes are enabled:
Enter an exact search string either via ascii characters or via hexadecimal interpretation. This is the fastest search mode. You may specify a case-insensitive search.
Enter an expression, it will be evaluated ONCE (difference to the 4th mode),
and HT will then search for the result-string. This is pretty useful when
searching for intermixed text and control-chars/binary, e.g. "hello world\n\0"
As the prefix indicates, this search doesn’t search in the binary file but
in the display on screen. HT searches for a regular expression so this can
be very powerful, e.g. in PE/Image you can search for (add|sub).+?,\ [78]$.
This will find all add or sub instructions with second parameter 7 or 8.
This is the slowest but also most advanced search mode. Enter an expression
and the search stops if this expression evaluates to non-zero (it will be
evaluated on every byte). In this mode there are two predefined symbols
and some functions: i is always the number of current iteration and
o stands for the current offset in file. With the functions readbyte(ofs)
and readstring(ofs, size) you access the file’s content.
It’s easier to understand this with examples:
readbyte(o) == readbyte(o+1)(readbyte(o) == readbyte(o+1)-1) && (readbyte(o)==readbyte(o+2)-2)With HT you can easily detect the RSA key in the ADVAPI32.DLL:
Search for entropy(readstring(o, 64)) > 82 in expr!=0 mode, and you will
find it very quickly. How does it work? readstring(o, 64) reads a 64 byte string
from current offset and entropy calculates the entropy ("randomness") of a string (result is 0..100).
So the search stops if a entropy greater than 82% (guessed value)
is encountered, which normally indicates packed or encryted data.
Note: the entropy() function is not the best of its kind, if you know of a better
one please let us know!
-- | treat all additional parameters as file names | |
-v | --version | show version and copyright on console |
-h | --help | show help |
-t | --text | load file(s) in text editor mode |
-b | --bin | load file(s) in hex editor mode |
-a | --auto | try to guess file type |
The HT homepage is located at http://hte.sourceforge.net
Downloads are available from the ’download’ section. Please also take a look at http://sourceforge.net/projects/hte