Send a message to Slack

message-to-Slack.bash

#!/bin/bash

# default
if [ -z ${CURL+x} ]; then
    CURL="/usr/bin/curl"
fi
if [ -z ${ECHO+x} ]; then
    ECHO="/usr/bin/echo"
fi
if [ -z ${CUT+x} ]; then
    CUT="/usr/bin/cut"
fi

# webhook_url, MSG_PREFIX, & CURL, ECHO, CUT if necessary
CONF="${HOME}/.Slack.conf"
source ${CONF}

if [ -z ${MSG_PREFIX+x} ]; then
    MSG_PREFIX=""
fi

if [ -z ${MSG_APPENDIX+x} ]; then
    MSG_APPENDIX=""
fi

if [ -z ${text+x} ]; then
    text="${1}"
fi

prefixMode=$(${ECHO} "${text}" | ${CUT} -c 1-4)
if [ "${prefixMode}" == "YPM0" ]; then
    text=$(${ECHO} "${text}" | ${CUT} -c 5-)
elif [ "${prefixMode}" == "YPM1" ]; then
    text=$(${ECHO} "${text}" | ${CUT} -c 5-)
    msg=$(eval ${ECHO} "${text}")
    text=$(${ECHO} -e "${msg}")
fi

text="${MSG_PREFIX}${text}${MSG_APPENDIX}"

curl --insecure -X POST -H 'Content-type: application/json' --data '{"text":"'"${text}"'"}' "${webhook_url}"