Make a simple script that will regex multiple expressions from a log tail

I have a log file that I am tailing for live messages of a chat client . Each message has an id in the first column, which will be the variable for every parsed message . The script needs to be able to filter out messages based on both matched expressions and expressions that I want to filter out . For every message id matching an expression that is parsed, it will be immediatly sent as a variable in this way : echo -e 'message message_id' | netcat command Logic : If expression match AND if expression not banned >> set msg id as variable and echo command . The script obviously needs to be continuously running for parsing the log file in real time . Will only consider proposals that show you have read the details .