watch files for specific patterns
logalert is a logfile monitoring tool which executes a specific action whenever it
matches a string (pattern) occurrence.
It reads an entire file (or starts at the end, just like tail -f), keeps track of
any changes, waiting for a specific pattern (a syslog process error, a user login,
...) and fires an action you define when that happens.
logalert uses regular expression to match the pattern occurrence and executes com‐
mands via shell interaction. It deals fine with logrotation and temporary removal
normally used by sysadmins.