Oh heck, why not - here's a slightly improved design. Run it in the background, and it will write the user defined above when it sees the exact phrase (also defined above).
It's not the pertiest, and probably not the fastest if the logs grows very quickly, but it works, and it's be easy to modify to mail, page, whatever...
Just be careful that it doesn't flood you out if it finds the same message hundreds of times...
Code:
#! /bin/ksh
search_word="search terms"
write_user=user_id
tail -n1 -f /path/to/log |&
while read -p output_line; do
[[ $output_line == *"$search_word"* ]] && {
print "$output_line" | write $write_user
}
done
