This script uses 'logtail' to monitor log activity for selected logfiles and beep the PC speaker when new log messages are discovered.

log-alarm

#!/bin/bash

# this script beeps the PC speaker when there are new messages available
#  and shows the new messaegs

#
# REQUIREMENTS:
#
# the script requires "logtail" and "beep" to function
# it requires kernel modules to be loaded: "pcspkr" & "snd_pcsp"
# also, adjust 'log_files' and 'logtail_offset_dir' accordingly

log_files_locations="/var/log/switches/*/switch.log"
logtail_offset_dir="/tmp/log-alarm_offset"
minutes_to_be_in_noclear_mode=14

################ DO NOT CHANGE THE CODE BELOW #################
## environment stuff ##
#set -x
mkdir -p $logtail_offset_dir
chmod -R a+rw $logtail_offset_dir &> /dev/null
iteration=1
very_first_iteration=true
noclear_mode=false
seconds_between_iterations=20
first_iterations=$(( ($minutes_to_be_in_noclear_mode * 60) / $seconds_between_iterations ))
# a countdown time mode after the first number iterations after noclear_mode expires
iterations_before_counting=true

while true; do
  if ! $noclear_mode; then clear; fi
  new_log_output=""

  for file in $log_files_locations; do
    new_log_output+="$(logtail -f "$file" -o "$logtail_offset_dir/${file//\//_}.offset")"
  done

  if [[ -z "$(echo "$new_log_output" | sed -e 's/^[ \t]*//i')" ]]; then # if there's no new log output
    if ! $noclear_mode ; then
      minutes=$(( ($seconds_between_iterations * $iteration) / 60 ))
      if (( $iteration < $first_iterations )) && ! $very_first_iterations && $iterations_before_counting; then
        iterations_before_counting=false
        minutes=$minutes_to_be_in_noclear_mode
      fi
      echo -ne " \e[0;32m-------- There's no new log output for the last \e[0;31m$minutes minute(s)\e[0;32m --------\e[0m "
    fi

    if $noclear_mode && [ $(($iteration * $seconds_between_iterations)) -gt $((60 * $minutes_to_be_in_noclear_mode)) ]; then
    # turning off noclear_mode if the iterations time (in seconds) is greater then seconds in noclear_mode allowed
      noclear_mode=false
      iteration=0
    fi
  else
    iteration=0
    noclear_mode=true
    iterations_before_counting=true
    beep -l 1000 -r 2 -d 100
    echo -ne "\n$new_log_output"
  fi
  let iteration++
  very_first_iteration=false
  sleep $seconds_between_iterations
done