ircmsg.sh



    1 #!/bin/bash
    2 #
    3 # Ircmsg sends messages to irc servers using bash sockets.
    4 # Copyright (C)  2016  Aaron Ball <nullspoon@oper.io>
    5 #
    6 # This program is free software: you can redistribute it and/or modify
    7 # it under the terms of the GNU General Public License as published by
    8 # the Free Software Foundation, either version 3 of the License, or
    9 # (at your option) any later version.
   10 #
   11 # This program is distributed in the hope that it will be useful,
   12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   14 # GNU General Public License for more details.
   15 #
   16 # You should have received a copy of the GNU General Public License
   17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
   18 #
   19 
   20 portfd=''
   21 
   22 #
   23 # Takes active file descriptor to irc server and reads until finding a line
   24 # matching "PING". Retrieves value of that line (without the PING prefix), and
   25 # returns so the corresponding PONG can be sent.
   26 #
   27 # Note: This function will timeout when reading from the server 100 times
   28 #
   29 function get_ping {
   30   local portfd=${1}
   31   local emptymax=50
   32   local emptycount=0
   33 
   34   # get ping
   35   while [[ ${emptycount} -lt ${emptymax} ]]; do
   36     read ping <&${portfd}
   37 
   38     # If first four match PING, break and process
   39     [[ ${ping:0:4} == 'PING' ]] && break
   40 
   41     # If response is empty, increment empty counter
   42     [[ ${ping} == '' ]] && emptycount=$(($emptycount + 1))
   43   done
   44   
   45   ping=${ping:5}
   46   echo "${ping}"
   47 }
   48 
   49 
   50 # function connect {
   51 #   local server=${1}
   52 #   local port=${2}
   53 # 
   54 #   # Open the socket
   55 #   exec {portfd}<>/dev/tcp/${server}/${port}
   56 # 
   57 #   # Exit on failure
   58 #   [[ $? -gt 0 ]] && echo "Failed to connect to ${server}:${port}." && exit 1
   59 # 
   60 #   echo "${portfd}"
   61 # }
   62 
   63 
   64 function close_sock {
   65   local portfd=${1}
   66 
   67   # Close read
   68   exec {portfd}<&-
   69   # Close write
   70   exec {portfd}>&-
   71 }
   72 
   73 
   74 function main {
   75   argv=(${@})
   76 
   77   [[ -z ${1} ]] && echo "Please specify a server." && exit 1
   78   [[ -z ${2} ]] && echo "Please specify a server port." && exit 1
   79   [[ -z ${3} ]] && echo "Please specify a channel." && exit 1
   80   [[ -z ${4} ]] && echo "Please specify a message." && exit 1
   81 
   82   # Config
   83   nick="ircmsg"
   84   server="${1}"
   85   port="${2}"
   86   chan="${3}"
   87   msg="${4}"
   88 
   89   # Open the socket
   90   exec {portfd}<>/dev/tcp/${server}/${port}
   91   # Exit on failure
   92   [[ $? -gt 0 ]] && echo "Failed to connect to ${server}:${port}." && exit 1
   93 
   94   # Authenticate
   95   echo "NICK ${nick}" >&${portfd}
   96   echo "USER ${nick} 8 * : ${nick}" >&${portfd}
   97 
   98   # Respond to the server with its ping value (ping pong)
   99   ping=$(get_ping ${portfd})
  100   if [[ ${ping} == '' ]]; then
  101     echo "ERROR: No PING response received. Cannot continue."
  102     exit 1
  103   fi
  104 
  105   echo "PONG ${ping}" >&${portfd}
  106 
  107   # Send message to specified channel
  108   echo "PRIVMSG ${chan} ${msg}" >&${portfd}
  109 
  110   # Send quit command
  111   echo "QUIT :All done!" >&${portfd}
  112 
  113   # Close up shop
  114   close_sock ${portfd}
  115 }
  116 
  117 main "${@}"