irctk

libircclient binding for scripts
git clone https://a3nm.net/git/irctk/
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README (21671B)


      1 irctk -- an IRC toolkit
      2 Copyright (C) 2010-2018 by Antoine Amarilli
      3 
      4 == 0. License ==
      5 
      6 This program is free software: you can redistribute it and/or modify it under
      7 the terms of the GNU General Public License as published by the Free Software
      8 Foundation, version 3.
      9 
     10 This program is distributed in the hope that it will be useful, but WITHOUT ANY
     11 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
     12 PARTICULAR PURPOSE.  See the GNU General Public License for more details.
     13 
     14 You should have received a copy of the GNU General Public License along with
     15 this program (see file "COPYING").  If not, see <https://www.gnu.org/licenses/>.
     16 
     17 == 1. Description ==
     18 
     19 irctk is a general-purpose IRC toolkit. It connects to an IRC server specified
     20 on the command line, joins channels specified on the command line, posts what it
     21 receives from stdin to the channels and outputs to stdout what it hears on the
     22 channels. This makes it possible to write simple IRC bots and scripts very
     23 quickly, either in the shell or in your favourite programming language.
     24 
     25 == 2. Installation ==
     26 
     27 You will need the libircclient library (version >= 1.8) to compile and run
     28 irctk. On Debian jessie and later, sufficiently recent versions can be installed
     29 with:
     30 
     31   sudo apt-get install libircclient1 libircclient-dev
     32 
     33 However, these versions are compiled without SSL support, so irctk will not
     34 support SSL. If you wish to use SSL, you need to compile libircclient yourself
     35 (explained below).
     36 
     37 You can then compile irctk by issuing "make". Install irctk by yourself in a
     38 location of your PATH if you want to use it as "irctk", otherwise replace
     39 "irctk" by "./irctk" in the next examples.
     40 
     41 The rest of this section presents how to compile libircclient by yourself if
     42 necessary, and how to install irctk without requiring root privileges.
     43 
     44 === 2.1. Compiling libircclient ===
     45 
     46 First, if you want support for SSL, you need to install the OpenSSL library and
     47 header files. You need to use OpenSSL version 1.0.2, *not* OpenSSL version 1.1.
     48 On Debian stretch and later, you can do so by running:
     49 
     50   sudo apt-get install libssl1.0-dev
     51 
     52 Second, you should get the latest libircclient (currently libircclient-1.9) from
     53 <https://sourceforge.net/projects/libircclient/>, compile it and install it
     54 (this requires of course make, a C compiler, etc., which you can get on Debian
     55 systems by installing e.g. the package build-essential). Then run:
     56 
     57   ./configure -enable-openssl --enable-shared
     58   make
     59   sudo make install
     60 
     61 === 2.2. Installing without root ===
     62 
     63 If you cannot install libircclient system-wide, compile it as previously
     64 explained, without the "sudo" command. Then, issue (in the libircclient folder):
     65 
     66   cd src
     67   ln -s libircclient.so libircclient.so.1
     68   cd ..
     69 
     70 Now go back to the irctk folder, and edit the Makefile to add the following at
     71 the end of the CFLAGS line, adjusting for the location of the libircclient
     72 folder:
     73 
     74   -I/where/you/put/libircclient-1.9/include
     75 
     76 Compile with "make", and now run irctk with the following invocation:
     77 
     78   LD_LIBRARY_PATH="/where/you/put/libircclient-1.9/src/:$LD_LIBRARY_PATH" ./irctk
     79 
     80 == 3. How to use ==
     81 
     82 === 3.1. Connecting to a server ===
     83 
     84 As a simple interactive use of irctk, here is how you connect to the IRC server
     85 at example.com and join channel #test:
     86 
     87   $ irctk example.com '#test'
     88 
     89 Messages on the channel will get output on your terminal, and you can type
     90 messages that you want so say to the channel. Press ^D to close stdin and
     91 terminate irctk. Note that the use of quotes around "#test" is to prevent your
     92 shell from interpreting '#' (irctk won't see them).
     93 
     94 More elaborate options are supported. Here is how to connect to a
     95 password-protected channel on a password-protected server on a non-standard
     96 port, specifying a custom nickname, username and real name.
     97 
     98   $ irctk -U jh -R "J. Hacker" nick:srvpass@example.com:3724 '#test:chanpass'
     99 
    100 To connect to a server with SSL support, run:
    101 
    102   $ irctk --ssl example.com
    103 
    104 To additionally disable SSL certificate checking, and allow self-signed and
    105 invalid certificates (at the risk of falling in a man-in-the-middle attack),
    106 run:
    107 
    108   $ irctk --ssl --no-check-certificate example.com
    109 
    110 Connection will fail if you specify --ssl but the server does not support SSL,
    111 or vice versa.
    112 
    113 === 3.2. Using irctk's stdin ===
    114 
    115 irctk is meant to be used non-interactively. For instance, you can say the
    116 contents of a file on a channel by giving it as standard input:
    117 
    118   $ irctk flooder@example.com '#flood' <file
    119 
    120 Of course, it is more interesting to pipe to irctk something which will produce
    121 more and more lines as events occur. For instance, here is how to follow your
    122 server logs on IRC:
    123 
    124   $ ssh server tail -f logfile.log | irctk logger@example.com '#dashboard'
    125 
    126 If you receive mail to a mbox file, here is how you could use irctk to
    127 get a private message to notify you about the subjects of incoming emails.
    128 
    129   $ tail -f ~/mbox | grep --line-buffered '^Subject:' |
    130       irctk alert@example.com mynick
    131 
    132 Note the use of --line-buffered to make sure that the messages do not get
    133 buffered. Here is how to follow the RSS feed of Commandlinefu and post the
    134 commands to a channel as they appear in the feed:
    135 
    136   $ rsstail -u 'https://feeds2.feedburner.com/Command-line-fu' -NdzH -n 1 -i 300 |
    137       grep --line-buffered '^ \$ ' |
    138       irctk clfbot@example.com '#commandlinefu'
    139 
    140 === 3.3. Using irctk's stdout ===
    141 
    142 You can log what is happening on a channel by setting stdout to be a file:
    143 
    144   $ irctk logger@example.com '#chan' >file
    145 
    146 You can add timestamps:
    147 
    148   $ irctk logger@example.com '#chan' |
    149       awk '{ print strftime("%s"), $0; fflush() }' > file
    150 
    151 Caution, if you want to run irctk in the background to do something like this,
    152 you need to prevent it from reading stdin (to avoid it being suspended) without
    153 closing stdin (otherwise irctk will terminate). Here is how:
    154 
    155   $ tail -f /dev/null | irctk logger@example.com '#chan' >file &
    156 
    157 Another example: play a sound whenever your nick is mentioned (but not when you
    158 speak):
    159 
    160   $ irctk example.com '#chan' |
    161       grep --line-buffered '[^<]yournick' | while read l; do
    162         aplay alert.wav;
    163       done
    164 
    165 irctk has specific features to detect when someone addresses it. Say you want to
    166 log tasks to do by addressing a bot on IRC:
    167 
    168   $ irctk -f todobot@example.com '#chan' >>~/todo
    169 
    170 To append lines to ~/todo, you can either address todobot on #chan through
    171 messages like "todobot: buy some milk", or you can send a private message to
    172 todobot (using irssi, "/msg todobot write a poem to alice"). Note that the lines
    173 logged in ~/todo will look like "[#chan] <mynick> todobot: buy some milk"; if
    174 you want to get rid of the cruft, you can use:
    175 
    176   $ irctk -F todobot@example.com '#chan' >>~/todo
    177 
    178 which will only log "buy some milk" (and implies -f).
    179 
    180 To combine the use of stdin and stdout, this invocation pipes two irctk calls
    181 together to relay messages from source.com to destination.com (but not the
    182 reverse):
    183 
    184   $ irctk listener@source.com '#chan1' |
    185      irctk repeater@destination.com '#chan2'
    186 
    187 === 3.4. Writing interactive bots ===
    188 
    189 We will now look at interactive examples where you interface irctk's stdout to
    190 some script or program which will do something intelligent and give something to
    191 say to irctk in return. To do so, we will need a named FIFO:
    192 
    193   $ mkfifo fifo
    194 
    195 As an extremely simple interactive program, consider the following:
    196 
    197   $ cat fifo | irctk pongbot@example.com '#chan' |
    198       awk '/[^<]ping/ { print "pong"; fflush() }' > fifo
    199 
    200 The awk invocation outputs "pong" whenever it sees a line containing "ping"
    201 (excluding things such as "<ping" to avoid the issue of people with a nick
    202 starting with "ping"). This means that pongbot will say "pong" on #chan whenever
    203 someone says something containing "ping". Note the use of fflush(), once again
    204 to avoid buffering. The named FIFO is used to connect irctk's stdout to awk's
    205 stdin and awk's stdout to irctk's stdin. Note that the cat invocation is
    206 required and "<fifo" will not work.
    207 
    208 Of course, you can use your favorite programming language instead of awk. If you
    209 want to write an IRC bot in an esoteric language with no IRC library (or maybe
    210 even no networking support), all you need to do is write some code which reads
    211 incoming lines on stdin, posts outgoing lines on stdout, and *does not buffer*.
    212 You can then lift your program to IRC very simply:
    213 
    214   $ cat fifo | irctk example.com '#chat' | program > fifo
    215 
    216 === 3.5. Input and output format ===
    217 
    218 The output format of irctk is of the following form (unless you use -F):
    219 
    220   [#chan] <nick> message
    221 
    222 By default, server events (joins, kicks, renames, etc.) are not output. If you
    223 want them, you can either get them in a human-readable form with the -m flag:
    224 
    225   [#bar] -!- foo has joined #bar
    226 
    227 Alternatively, you can get them in a barebones form with -c:
    228 
    229   [#bar] <foo> /join #bar
    230 
    231 Your own messages will not be included unless you specify --own. If you want to
    232 see nicknames like <nick!~username@localhost>, use --with-host. You can also use
    233 the -f and -F options presented above to only keep lines addressed to you and to
    234 remove everything but the message (-F implies -f).
    235 
    236 The input format is of the following form:
    237 
    238   [channel] message
    239 
    240 The channel can be either of the form "#chan" (a regular channel) or of the form
    241 "user" (the channel of private messages exchanged with user). You can specify
    242 multiple channel names separated by commas (but see the section "Pipelining"
    243 below).
    244 
    245 Because specifying the chan each time can be tedious, irctk can try to guess it.
    246 If you do not specify a destination and just give a message, irctk will say it
    247 to the last active channel by default (i.e., the last channel where something
    248 was heard), which is often a reasonable choice if you are replying to someone.
    249 There are other possible options: see the section "Implied destinations" below.
    250 
    251 irctk will always try to join a channel before saying something to this channel.
    252 This means that it can join entirely new channels in this fashion. To disable
    253 this behavior and prevent irctk from joining any channels except the ones given
    254 at startup, use --no-join (can be useful if irctk's stdin is
    255 attacker-controlled). Note that this only affects the behavior of irctk on
    256 regular channels: even with --no-join, irctk will be able to send private
    257 messages to anyone, and will try to send messages to unknown channels (just
    258 without trying to join them first).
    259 
    260 irctk will interpret some commands starting with '/' in a fashion similar to
    261 irssi. To inhibit this (can be useful if irctk's stdin is attacker-controlled),
    262 use --no-command-to-event.
    263 
    264 When irctk is provided attacker-controlled input, the right way to escape is to
    265 prepend '/say' or '/ ' before every line provided to irctk (be careful if the
    266 attacker may provide newlines).
    267 
    268 The supported commands are:
    269 
    270   /nick NICKNAME (change nick)
    271   /mode MODE (set channel mode)
    272   /part [CHAN] (part from a channel)
    273   /join [CHAN] (join a channel)
    274   /topic TOPIC (set channel topic)
    275   /quit REASON (quit)
    276   /invite USER [CHAN] (invite a user to a channel)
    277   /kick USER [REASON] (kick user from current inferred destination)
    278   /me MSG (/me message)
    279   /notice MSG (say as a notice)
    280   /oper USER [PASS] (obtain operator privileges)
    281   /quote COMMAND (send raw command to IRC server)
    282   /say MSG (escape)
    283   / MSG (escape)
    284   /notice MSG (like /say but use NOTICE)
    285 
    286 Optional channel names "[CHAN]" in the above list default to the current
    287 inferred destination (i.e., the last active channel by default).
    288 
    289 As an additional convenience, irctk can be made to address the last person who
    290 addressed it, with the -r option. In conjunction with the default destination
    291 channel inference, this means that, using -fr, whenever you ask irctk to say
    292 "message", it will say that to the last person who addressed it, on the channel
    293 where it was addressed. This is very convenient to write bots.
    294 
    295 === 3.6. Complete examples ===
    296 
    297 This bot queries user names using finger and returns a status line for them (or
    298 an error if they do not exist):
    299 
    300 cat fifo | irctk -Fr fingerbot@example.com '#chat' |
    301   while read; do
    302     finger -s -- "$REPLY" 2>&1 | tail -1
    303   done >fifo
    304 
    305 The following bot can be used to roll dice: say something like "dmbot: 3d42" and
    306 it will reply with the result. Note that this example is bash-specific. Thanks
    307 to p4bl0 <https://pablo.rauzy.name/> for writing it.
    308 
    309 cat fifo | irctk -Fr dmbot@example.com '#chat' |
    310   while read line; do
    311     if grep -E '^[0-9]{1,2}d[0-9]{1,3}$' <<<"$line" &>/dev/null; then
    312       D=(${line/d/ })
    313       for ((i = 0; i < ${D[0]}; i++)); do
    314         echo -n $((RANDOM % ${D[1]} + 1))" "
    315       done
    316       echo
    317     else
    318       echo "format error: must be NdM with N<100 and M<1000"
    319     fi
    320   done >fifo
    321 
    322 This bot queries on wikipedia whatever is said to it, using the DNS-based
    323 wikipedia query system as an ugly way to get the beginning of pages.
    324 
    325   $ cat fifo | irctk -Fr wikibot@example.com '#chat' |
    326       while read line; do
    327         Q=$(echo "$line" | tr ' ' '_' | tr -dc 'a-zA-Z_()');
    328         dig +short txt $Q.wp.dg.cx; echo;
    329       done >fifo
    330 
    331 This is a way to play adventure on IRC. (Beware, people can overwrite files when
    332 saving their game, so run as a suitably unpriviledged user.) The "while true"
    333 loop is to restart the game whenever it exits. The socat invocation is used to
    334 disable buffering. To play, say "DM: command".
    335 
    336   $ cat fifo | irctk -F DM@example.com '#adventure' |
    337       while true; do
    338         socat EXEC:adventure,pty,ctty,echo=0 STDIO;
    339       done >fifo
    340 
    341 Two-way gateway: gateway posts on #chan1 on server1.com whatever is said to it
    342 on #chan2 on server2.com, and vice-versa:
    343 
    344   $ cat fifo | irctk -F0 gateway@server1.com '#chan1' |
    345       irctk -F0 gateway@server2.com '#chan2' | tee fifo
    346 
    347 Run shell commands from your IRC client (just by saying them in #tty, no need to
    348 address the bot). BEWARE, this means that whoever is named "admin" on the IRC
    349 server can run arbitrary commands on your machine, so you really shouldn't do
    350 this.
    351 
    352   $ cat fifo | irctk localhost '#tty' |
    353       grep --line-buffered '^\[#tty\] <admin>' |
    354       sed -u 's/^[^>]*> *//' | bash >fifo 2>&1
    355 
    356 Whatever admin says on #tty will get run in a bash shell and the result will be
    357 returned to the channel. Note that you can of course run irctk in this shell
    358 (irception!), but beware of feedback loops if you attempt to join the same
    359 channel!
    360 
    361 === 3.7. Implied destinations ===
    362 
    363 You can always specify the channel to which you speak by using a "[#channel]"
    364 prefix. You can specify multiple channels for the same message using commas (but
    365 see "Pipelining"). If you do not specify a channel, then irctk will choose one
    366 itself. Note that you can start your message with "[]" if your message starts
    367 with a '[' but you want irctk to infer the channel.
    368 
    369 Several possible ways to choose are available, only one of them can be provided
    370 on the command line. Here are those options, sorted by ascending complexity. A
    371 discussion of other useful options follows.
    372 
    373   * --default-always-first
    374 
    375 Messages with no destination will be sent to the first channel specified on the
    376 command line invocation of irctk (or to irctk's private channel if none were
    377 specified, which is not very useful).
    378 
    379   * --default-all
    380 
    381 Messages with no destination will be sent to all channels specified on the
    382 command line invocation of irctk. (They will *not* be sent to other channels
    383 that might have been joined by irctk later.)
    384 
    385   * --default-last-posted
    386 
    387 Messages with no destination will be sent to the last channel to which a message
    388 was sent. This is useful if you are writing to stdin manually and want to
    389 specify the channel only when it changes. Note that you can use -P to display
    390 the current default destination on stderr; if you send irctk's stdout elsewhere
    391 to avoid clobbering your terminal, this makes irctk (almost) look like irssi's
    392 prompt. (For instance, you can send stdout to a FIFO and display it in another
    393 window (or use GNU screen) to get a poor man's IRC client.)
    394 
    395   * --default-last-active (default)
    396 
    397 Messages with no destination will be sent to the last active channel, that is,
    398 the last channel on which something took place. This is reasonable if you want
    399 to react instantaneously to something which just happened. Note that because
    400 irctk reads stdin as greedily as possible, the last active channel should be the
    401 last active at the moment when you *write* your message to irctk's stdin, not at
    402 the moment when irctk will *say* it (the two differ if irctk has a long pipe of
    403 things to say). irctk's behavior is usually what you expect here.
    404 
    405 The --default-last-active option is perfect if you want to reply to messages by
    406 users and if your replies are instantaneous. If your replies take time and other
    407 requests may arrive during that time, irctk will not be able to route the
    408 answers on its own: consider writing your own logic to route messages according
    409 to your needs (and always specify the destination explicitly).
    410 
    411 === 3.8. Tracking ===
    412 
    413 Because of the delay between messages which irctk observes to avoid getting
    414 kicked by a pissed server, messages can be sent to the server a long time after
    415 irctk received them on stdin. This means that if you addressed someone doing
    416 something like "nick: message" or "[nick] message" or using -r, then that person
    417 might have changed nick in the meantime and the message may not get routed
    418 correctly.
    419 
    420 As a countermeasure, you can specify --track-renames so that messages addressed
    421 to a user in one of the above fashions get sent to the user's current nick.
    422 (They will get sent to their last known nick if they part or quit.) There is
    423 also a --unique-names options with which irctk will maintain unique names for
    424 users (based on the first seen nick for a user), expose them on stdout, and
    425 expect them on stdin. This is useful if you want to write a bot which stores
    426 e.g. a score for each user and if you want users to keep their score even if
    427 they change nick. These tracking modes are not enabled by default.
    428 
    429 Note: because a rename may be seen too late, this option is not guaranteed to
    430 work, and some messages may get mistakenly addressed to an older nick.
    431 
    432 === 3.9. Pipelining ===
    433 
    434 irctk has a built-in rate limitation (configurable with -i) which it tries to
    435 apply independently on each channel. This means that, to ensure the fastest
    436 possible delivery, messages to channels with an empty queue will be sent
    437 *before* messages to channels with a busy queue. no matter the order on which
    438 they were provided on standard input. However, within a given channel, the order
    439 relation on messages will match their order on standard input.
    440 
    441 If you specify multiple destination channels like "[#a,#b,#c]", however, the
    442 resulting message will be said on all the channels simultaneously (and will
    443 therefore wait for the buffers of all relevant channels to be empty). If you do
    444 not want this synchronization, you should say the message several times,
    445 addressed to each individual channel.
    446 
    447 Beware of the fact that the IRC server may limit irctk's rate in a fashion which
    448 irctk will not be able to control, so any slowdowns you see may not be irctk's
    449 fault. Use -o to see when irctk is sending your messages, to see who is slowing
    450 things down.
    451 
    452 == 4. Test suite ==
    453 
    454 You can run the test suite with ./tests_sequential.sh. This requires a working
    455 IRC server on localhost:6667. I use ircd-hybrid from Debian testing, configured
    456 with throttle_time = 0 and anti_spam_exit_message_time = 0. This also requires
    457 valgrind (which is packaged for Debian).
    458 
    459 If you have GNU parallel and if your IRC server isn't afraid of many connections
    460 from a single IP, you can run the tests in parallel: ./tests_parallel.sh. This
    461 isn't guaranteed to work.
    462 
    463 == 5. Caveats, limitations and FAQ ==
    464 
    465 irctk has not been thoroughly audited for bugs or security vulnerabilities. Be
    466 cautious if you intend to connect it to an IRC server with untrusted users.
    467 
    468 IRC servers will usually throttle clients. If want to set up chatty bots, you
    469 will need to have control over the IRC server and configure it adequately (for
    470 ircd-hybrid, look at "can_flood" and also at "default_floodcount").
    471 
    472 irctk will exit whenever it has sent all messages on stdin to the server. If the
    473 server throttles it, then it might exit before all messages have been
    474 delivered, and some may get lost. Use -i and -I, or sleep for a few seconds
    475 before closing stdin.
    476 
    477 You need to use tail -f /dev/null as input if you want to background irctk
    478 without having it suspend or exit (see above).
    479 
    480 irctk may say greedily the first things it sees on stdin while things to say in
    481 parallel might be available later.
    482 
    483 irctk can have trouble with buffering. When writing pipelines involving irctk,
    484 be sure to disable all buffering (sed -u, awk's fflush, python -u, stdbuf in
    485 some cases, etc.).
    486 
    487 If you get a "LIBIRC_ERR_SSL_NOT_SUPPORTED not declared" error when compiling,
    488 it means you are not compiling against the right version of libircclient (see
    489 section 2).
    490 
    491 == 6. Related projects ==
    492 
    493   * ii <https://tools.suckless.org/ii/>
    494 
    495 ii is filesystem and FIFO-based but irctk is entirely FIFO-based. ii's control
    496 FIFO is irctk's stdin, but ii's output files are replaced by irctk's stdout.
    497 irctk does not write to disk or read from disk. irctk also includes features
    498 which make it easy to write bots in shell script one-liners.
    499 
    500   * sic <https://tools.suckless.org/sic>
    501 
    502 sic is pretty similar to irctk, except irctk abstracts more things from the
    503 underlying IRC protocol and has more features (e.g., SSL support and the various
    504 options). Conversely, sic is <= 250 LOC without dependency on an external
    505 library.
    506 
    507   * IrcTK <https://github.com/maxcountryman/irctk>
    508 
    509 irctk has nothing to do with this except the similar name.
    510