A keyboard layout encoder filter: type input using a certain keyboard layout, see the output as if you were typing in another layout.

I use the Dvorak keyboard layout ( you should too :) ), and I often fumble around the traditional antiquated QWERTY layout if I need to quickly use someone else's computer to show him or her something. I could add the Dvorak Keyboard to his or her user preferences, but kbdencode presents an alternate solution: I can type what I want on a QWERTY keyboard as if it were a Dvorak keyboard, and then convert the gibberish into what I had typed.

<<<<<<< HEAD kbdencode is built with CMake. The easiest way to install kbdencode is to download a distribution package from the releases tab. Alternatively, you can compile the project as follows:

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make
make install

NOTE: kbdencode has a build dependency on the Boost program_options library by Vladimir Prus for parsing command-line options. A snapshot of this library from version 1.57.0 (current at the time of development) is included for convenience.

The default installation directory is /usr/local, and the last command might require super user permissions: sudo make install.

To install kbdencode to a custom directory (e.g. under the .local directory in your home directory), set the CMAKE_INSTALL_PREFIX flag on initial configuration:

cmake -DCMAKE_INSTALL_PREFIX=$HOME/.local ..

While this is not relevant for kbdencode (since it has only one source file), the build process can be greatly optimized by using the -jN flag on the make command. This specifies the number of parallel build threads that can be executed simultaneously. For example, an Intel Core i7 quad-core processor can run up to 8 threads:

make -j8

As it suits my needs, the default encoding direction is --from=qwerty, --to=dvorak. At present, the only command line options are --from=<layout>, --to=<layout>, --help, and --config=<file>; and the only named layouts are qwerty and dvorak. Instructions for specifying additional layouts are listed in the next section.

Files to decode can be specified as extra command-line arguments:

user@host:~ % kbdencode --from=qwerty --to=dvorak file1.txt file2.txt

kbdencode can handle text input through the standard input stream:

user@host:~ % echo "jdppsw ,soph!" | kbdencode
hello, world!

This makes it possible (but somewhat infeasible) to use a shell at the command line:

user@host:~ % kbdencode | zsh
p;
Destkop    Downloads  Music     Videos
Documents  Music      Pictures
ih Hs,lpsah;
r,h
/home/user/Downloads
,udk jkkrZ[[,sohrod;;esou[pakd;kekaoeu/
--2014-03-18 01:50:36--  http://wordpress.org/latest.tar.gz
Resolving wordpress.org... 66.155.40.250, 66.155.40.249
Connecting to wordpress.org|66.155.40.250|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 5869727 (5.6M) [application/x-gzip]
Saving to: 'latest.tar.gz'

100%[=======================================================================================>] 5,869,727   3.37MB/s   in 1.7s   

2014-03-18 01:50:39 (3.37 MB/s) - 'latest.tar.gz' saved [5869727/5869727]
^D
user@host:~ %

If you want to type a message to a friend so that no one can read it over your shoulder, you can type the message into a file using a different keyboard layout.

-- Encoded --
XrxS Yd. xci xrq ru e.ncjcrgo jdrjrnay. co cb yd. jaxcb.y b.qy yr yd.
p.upci.payrpv D.nl frgpo.nuw xgy erb-y n.y >k. o.. cyv [Ancj.

-- Decoded --
Bob: The big box of delicious chocolate is in the cabinet next to the
refrigerator. Help yourself, but don't let Eve see it. -Alice

NOTE: This cipher is not very secure. Please do not use this method to encode sensitive information.

The easiest way to specify new layouts is in a configuration file. The default configuration file location is $HOME/.kbdencoderc, and the format is extremely simple:

layout name
layout keymap string (see below)
layout name
layout keymap string (see below)
...

Built-in layouts are specified as an initializer list in the src/kbdencode.cc file. Layouts can also be specified as values to the --to and --from options. The format is simple:

1. type all the keys (without holding Shift) starting from the top-left (the backtick ` symbol on a QWERTY keyboard), working left-to-right, and ending at the bottom-right (the forward-slash / key on a QWERTY keyboard).
2. Repeat the process, but hold the Shift key down for all keys.
3. Be sure to escape any special characters as necessary.

For example, the QWERTY map is `1234567890-=qwertyuiop[]\asdfghjkl;'zxcvbnm,./~!@#$%^&*()_+QWERTYUIOP{}|ASDFGHJKL:"ZXCVBNM<>?

Revisiting the configuration file format, here is a concrete example of a configuration file containing the built-in qwerty and dvorak layouts:

qwerty
`1234567890-=qwertyuiop[]\asdfghjkl;'zxcvbnm,./~!@#$%^&*()_+QWERTYUIOP{}|ASDFGHJKL:"ZXCVBNM<>?
dvorak
`1234567890[]',.pyfgcrl/=\aoeuidhtns-;qjkxbmwvz~!@#$%^&*(){}"<>PYFGCRL?+|AOEUIDHTNS_:QJKXBMWVZ

kbdencode is licensed under the GPLv2 license. Full license details are available in the LICENSE file or at https://www.gnu.org/copyleft/gpl.html.

If the GPL presents a problem for you in any way, please let me know and I will consider relicensing the software for you.

The included Boost source code is licensed under the Boost Software License, version 1.0. Full license details are available in the libs/boost_1.57.0/LICENSE_1_0.txt file.