techblog 

This is a tip I’ve picked up at this link. It is in
Russian though.

If you want to highlight something when doing ‘tail -f’ you can use the
following command:

tail -f /var/log/logfile | perl -p -e
's/(something)/33[7;1m$133[0m/g;'

or if your terminal supports colours, e.g. linux terminal, you can use
this:

tail -f /var/log/logfile | perl -p -e
's/(something)/33[46;1m$133[0m/g;'

and if you want it to beep on a match use this:

tail -f /var/log/logfile | perl -p -e
's/(something)/33[46;1m$133[0m07/g;'

If you find that perl is too heavy for this you can use sed:

tail -f /var/log/logfile | sed
"s/(something)/^[[46;1m1^[[0m/g"

Note, that in the last example you have to actually type “cntl-v
cntl-[” in place of “^[”

For the full list of control characters on Linux you can look at ‘man
console_codes’.