Parrallel ongoing for each file loop?

Question

I want to continuously monitor some log files. What I have below works if I switch the tail -F for cat $log_file. When I use -tail -F the first log file works but because its process doesn't finish it blocks the top while loop.

How can I background each process so that the outer while read log_file starts a process for each log file? (also tried adding & in various places to background the inner while loop)

ls /var/log/myApp-*.log | while read log_file ; do
  tail -F $log_file while read log ; do
    echo send $log to external tracker for $log_file if X
  done
done

Answer 1

This solution uses awk to parse the output of tail and call a command with system() if the event is detected.

Also, you might want to avoid parsing the output of ls and using globbing instead.

for log_file in /var/log/myApp-*.log; do 
    tail -F $log_file | awk '{l=gensub(/.+\"level\": ([0-9]+).+/,"\\1","g",$0); if(l>50 && l!= $0){system("echo command")}}' &
done