xK/README.adoc

xK
==

'xK' (chat kit) is an IRC software suite consisting of a terminal client,
daemon, and bot.  It's all you're ever going to need for chatting,
so long as you can make do with slightly minimalist software.

They come with these potentially interesting properties:

 - supporting IRCv3, SOCKS, IPv6, TLS (including client certificates)
 - lean on dependencies
 - compact and arguably easy to hack on
 - maximally permissive license

xC
--
The IRC client, and the core of 'xK'.  It is largely defined by being built
on top of GNU Readline that has been hacked to death.  Its interface should feel
somewhat familiar for weechat or irssi users.

image::xC.png[align="center"]

It has most of the stuff you'd expect of an IRC client, such as being
multiserver, a powerful configuration system, integrated help, text formatting,
automatic splitting of overlong messages, multiline editing, bracketed paste
support, decent word wrapping, autocomplete, logging, CTCP queries, auto-away,
command aliases, and basic support for Lua scripting.  As a unique bonus,
you can launch a full text editor from within.

xD
--
The IRC daemon.  It is designed to be used as a regular user application rather
than a system-wide daemon.  If all you want is a decent, minimal IRCd for
testing purposes or a small network of respectful users (or bots), this one will
do it just fine.

Notable features:

 - TLS autodetection (I'm still wondering why everyone doesn't have this)
 - IRCop authentication via TLS client certificates
 - partial IRCv3 support

Not supported:

 - server linking (which also means no services); I consider existing protocols
   for this purpose ugly and tricky to implement correctly; I've also found no
   use for this feature yet
 - online changes to configuration; the configuration system from 'xC' could
   be used to implement this feature if needed
 - limits of almost any kind, just connections and mode `+l`

This program has been
https://git.janouch.name/p/haven/src/branch/master/hid[ported to Go],
and development continues over there.

xB
--
The IRC bot.  While originally intended to be a simple rewrite of my old GNU AWK
bot in C, it fairly quickly became a playground, and it eventually got me into
writing the rest of this package.

Its main characteristic is that it runs plugins as coprocesses, allowing for
enhanced reliability and programming language freedom.  Moreover, it recovers
from any crashes, and offers native SOCKS support (even though socksify can add
that easily to any program).

Packages
--------
Regular releases are sporadic.  git master should be stable enough.  You can get
a package with the latest development version from Archlinux's AUR.

Building
--------
Build dependencies: CMake, pkg-config, asciidoctor, awk, liberty (included) +
Runtime dependencies: openssl +
Additionally for 'xC': curses, libffi, lua >= 5.3 (optional),
                       readline >= 6.0 or libedit >= 2013-07-12

Avoid libedit if you can, in general it works but at the moment history is
acting up and I have no clue about fixing it.

 $ git clone --recursive https://git.janouch.name/p/xK.git
 $ mkdir xK/build
 $ cd xK/build
 $ cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=RelWithDebInfo \
            -DWANT_READLINE=ON -DWANT_LIBEDIT=OFF -DWANT_LUA=ON
 $ make

To install the application, you can do either the usual:

 # make install

Or you can try telling CMake to make a package for you:

 $ cpack -G DEB  # also supported: RPM, FreeBSD
 # dpkg -i xK-*.deb

Usage
-----
'xC' has in-program configuration.  Just run it and read the instructions.
Consult its link:xC.adoc[man page] for details about the interface.

For the rest you might want to generate a configuration file:

 $ xB --write-default-config
 $ xD --write-default-config

After making any necessary edits to the file (there are comments to aid you in
doing that), simply run the appropriate program with no arguments:

 $ xB
 $ xD

'xB' stays running in the foreground, therefore I recommend launching it inside
a Screen or tmux session.

'xD', on the other hand, immediately forks into the background.  Use the PID
file or something like `killall` if you want to terminate it.  You can run it
as a `forking` type systemd user service.

Client Certificates
-------------------
'xC' will use the SASL EXTERNAL method to authenticate using the TLS client
certificate specified by the respective server's `tls_cert` option if you add
`sasl` to the `capabilities` option and the server supports this.

'xD' uses SHA-1 fingerprints of TLS client certificates to authenticate users.
To get the fingerprint from a certificate file in the required form, use:

 $ openssl x509 -in public.pem -outform DER | sha1sum

Custom Key Bindings in xC
-------------------------
The default and preferred frontend used in 'xC' is GNU Readline.  This means
that you can change your bindings by editing '~/.inputrc'.  For example:

....
# Preload with system-wide settings
$include /etc/inputrc

# Make M-left and M-right reorder buffers
$if xC
"\e\e[C": move-buffer-right
"\e\e[D": move-buffer-left
$endif
....

Consult the source code and the GNU Readline manual for a list of available
functions.  Also refer to the latter for the exact syntax of this file.
Beware that you can easily break the program if you're not careful.

How do I make xC look like the screenshot?
------------------------------------------
With the defaults, 'xC' doesn't look too fancy because I don't want to have
a hard dependency on either Lua for the bundled script that provides an easily
adjustable enhanced prompt, or on 256-colour terminals.  Moreover, it's nearly
impossible to come up with a colour theme that would work well with both
black-on-white and white-on-black terminals, or anything wild in between.

Assuming that your build supports Lua plugins, and that you have a decent,
properly set-up terminal emulator, it suffices to run:

 /set behaviour.backlog_helper = Press Tab here and change +Gb to +Gb1d
 /set behaviour.date_change_line = "%a %e %b %Y"
 /set behaviour.plugin_autoload += "fancy-prompt.lua"
 /set attributes.userhost = "\x1b[38;5;109m"
 /set attributes.join = "\x1b[38;5;108m"
 /set attributes.part = "\x1b[38;5;138m"
 /set attributes.external = "\x1b[38;5;248m"
 /set attributes.timestamp = "\x1b[48;5;255m\x1b[38;5;250m"
 /set attributes.read_marker = "\x1b[38;5;202m"

Configuration profiles
----------------------
Even though the applications don't directly support configuration profiles,
they conform to the XDG standard, and thus you can change the location they
load configuration from via XDG_CONFIG_HOME (normally '~/.config') and the
location where store their data via XDG_DATA_HOME (normally '~/.local/share').

It would be relatively easy to make the applications assume whatever name you
run them under (for example by using symbolic links), and load different
configurations accordingly, but I consider it rather messy and unnecessary.

Contributing and Support
------------------------
Use https://git.janouch.name/p/xK to report any bugs, request features,
or submit pull requests.  `git send-email` is tolerated.  If you want to discuss
the project, feel free to join me at ircs://irc.janouch.name, channel #dev.

Bitcoin donations are accepted at: 12r5uEWEgcHC46xd64tt3hHt9EUvYYDHe9

License
-------
This software is released under the terms of the 0BSD license, the text of which
is included within the package along with the list of authors.

Note that 'xC' becomes GPL-licensed when you link it against GNU Readline,
but that is not a concern of this source package.  The licenses are compatible.