tail_color.sh

# functions

CLREOL=$'\x1B[K'

# ex. tail-color "/path/to/logs.log" "PHRASE TO EXTRA COLOR"
tail-color () {
  COLORS="-e 's/\(.*DEBUG.*\)/\o033[32m\1\o033[39m/'"
  COLORS="$COLORS -e 's/\(.*NOTICE.*\) /\o033[97m\1\o033[39m/'"
  COLORS="$COLORS -e 's/\(.*WARNING.*\) /\o033[93m\1\o033[39m/'"
  COLORS="$COLORS -e 's/\(.*ERROR.*\)/\o033[91m\1\o033[39m/'"
  COLORS="$COLORS -e 's/\(.*\(ALERT|EMERGENCY\).*\) /\o033[31m\1\o033[39m/'"
  COLORS="$COLORS -e 's/\(.*CRITICAL.*\)/\o033[41m\1\o033[49m/'"
  COLORS="$COLORS -e 's/\($2\)/\o033[36m\1\o033[39m/'"

  CMD="tail -n 100 --pid=$BASHPID -f $1 | sed --unbuffered $COLORS"
  echo "$CMD"
  eval ${CMD}
}

# ex. rotate "/path/to/logs.log"
rotate () {
  TAILPID=0

  function ctrl_c() {
    echo "** [Ctrl+C]: kill tail process $TAILPID"
    kill $TAILPID 2>/dev/null
  }

  echo "Pattern: $1"
  trap ctrl_c INT  
  CURRENT=null

  while true; do
  NEWLOG=$(eval "echo $1")

  if [[ $NEWLOG != $CURRENT  && -e "$NEWLOG" ]]
  then
    kill $TAILPID 2>/dev/null
    CURRENT=$NEWLOG
    echo -e "\e[44m==================== $CURRENT ====================${CLREOL}\e[49m"
    echo -e "\e[44mtail-color $CURRENT $2 &${CLREOL}"
    tail-color $CURRENT $2 &
    echo -e "\e[44m==================== $CURRENT ====================${CLREOL}\e[49m"
    TAILPID=$!
  fi
  sleep 1
  done
}