Question

I’ve been trying to make tail a little more readable for server startups. My current command filters out most of the INFO and DEBUG messages from the startup:

tail -F ../server/durango/log/server.log | grep -e "ERROR" -e "WARN" -e "Shutdown" -e "MicroKernel" | grep --color=auto -E 'MicroKernel|$'

What I would like to do is craft something that would highlight WARN in yellow and ERROR in red, and MicroKernel in green. I tried just piping grep –color=auto multiple times, but the only color that survives is the last command in the pipe.

Is there a one liner to do this? Or even a many-liner?

Answer 1

yes, there is way to do this. That is, as long as your terminal supports ANSI escape sequences. This is most terminals that exist.

I think I don’t need explain how to grep, sed etc. point is the color right?

see below, this will make

WARN yellow
ERROR red
foo   green

here is example:

kent$ echo "WARN
ERROR
foo"|sed 's#WARN#\x1b[33m&#; s#ERROR#\x1b[31m&#; s#foo#\x1b[32m&#'

Note: \x1b is hexadecimal for the ESC character (^VEsc).

to see the result: