Bash-script-framework

Bash File header

#!/bin/bash
#===============================================================================
#
#          FILE:  FILENAME.sh
# 
#         USAGE:  ./FILENAME.sh < options >
# 
#  REQUIREMENTS:  ifconfig snmptrap tr sed awk
#        AUTHOR:  Christopher S. Hubbard (), chubbard@iwillfearnoevil.com
#       COMPANY:  I Will Fear No Evil DOT com
#       VERSION:  2.0.1
#       CREATED:  02/18/2011 06:49:51 PM PST
#      REVISION:  Mary
#===============================================================================

Details

Revision starts at the letter A and goes through M

Version starts at 0.0.1 and increments when major changes happen

Requirements are what should be validated before running the script

Use function

usage (){
cat << EOF
Usage: $0 options

Options:
-h  show this help screen
-x  enable debug mode

example:

EOF
}

Verify dependencies

verify_deps() {
# needed="xmllint curl w3m snmptrap cut egrep expr"
needed="snmp_drop_oid.sh grep awk sed"
for i in `echo $needed`
do
  type $i >/dev/null 2>&1
  if [ $? -eq 1 ]; then
    echo "Status WARNING - I am missing mandatory component: $i"; exit 1
  fi
done
}

Basic JSON Logging framework

logger() {
if [ ! -e ${canonicaldirname}/logs ];then
  mkdir ${canonicaldirname}/logs
fi

local MESSAGE=${1}
# "Message" "ERR, or UOW" "Context id"
   if [ -z ${2} ];then
      # If there is no var 2, then this is NOT an error or UOW of some kind.
      local LOGGING="INFO"
      local CONTEXT1=${RANDOM}
   else
      local LOGGING="${2}"
      if [ -z ${3} ];then
         local CONTEXT1=${RANDOM}
      else
         local CONTEXT1="${3}"
      fi
   fi
LOGFILE="${canonicaldirname}/logs/$(date +%F)_someFile.log"
touch ${LOGFILE}
chmod 664 ${LOGFILE}

local APP_NAME=`echo $0 | awk -F'/' '{print $NF}'`
#echo "[[\"$(date -u +%FT%H:%M:%S)\", \"Event\", \"\", \"${LOGGING}\", \"`hostname`\", \"${APP_NAME}\", \"$$\", \"0\", \"${CONTEXT1}\", ,\"OPS\", \"${APP_NAME}\"], {\"Event\":\"${MESSAGE}\"}]" >> ${LOGFILE}

echo "\"$(date -u +%FT%H:%M:%S.%3N)\": [[ \"${LOGGING}\", \"$(hostname)\", \"${APP_NAME}\", \"$$\", \"${CONTEXT1}\"], {\"Event\":\"${MESSAGE}\"}]," >> ${LOGFILE}
}

# Begin the log file so JSON is valid
beginlog() {
if [ ! -e ${canonicaldirname}/logs ];then
  mkdir ${canonicaldirname}/logs
fi

LOGFILE="${canonicaldirname}/logs/$(date +%F)_someLog.log"
touch ${LOGFILE}
chmod 664 ${LOGFILE}
local DATA=$(tail -1 ${LOGFILE} | wc -m)

# character count is 2 due to carriage return in output
if [[ ${DATA} -gt 2 ]] ;then
  echo '}' >> ${LOGFILE}
fi
}
endlog() {
if [ ! -e ${canonicaldirname}/logs ];then
  mkdir ${canonicaldirname}/logs
fi

LOGFILE="${canonicaldirname}/logs/$(date +%F)_someLog.log"
touch ${LOGFILE}
chmod 664 ${LOGFILE}
local MESSAGE=${1}
# "Message" "ERR, or UOW" "Context id"
  if [ -z ${2} ];then
     # If there is no var 2, then this is NOT an error or UOW of some kind.
     local LOGGING="INFO"
     local CONTEXT1=${RANDOM}
  else
     local LOGGING="${2}"
     if [ -z ${3} ];then
        local CONTEXT1=${RANDOM}
     else
        local CONTEXT1="${3}"
     fi
  fi
  echo "\"$(date -u +%FT%H:%M:%S.%3N)\": [[\"${LOGGING}\", \"$(hostname)\", \"${APP_NAME}\", \"$$\", \"${CONTEXT1}\"], {\"Event\":\"${MESSAGE}\"}]" >> ${LOGFILE}
  echo '}' >> ${LOGFILE}
}
# Fatal errors follow the endlog function
fatal() {
endlog $[@]
}

Getopts framework

while getopts "hx" OPTION; do
  case ${OPTION} in
    h) usage; exit 0 ;;
    x) export PS4='+(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'; set -v ;set -x ;;
    *) echo "Status FATAL - Unexpected arguments given.  Try -h.  Used $@"; exit 2 ;;
  esac
done