I need to get notification via email when the line containing a pattern is changed in a file. Not during the time any changes to file occurs. Ie if we reset a user password say example, demouser the hash in the line containing the word demouser in the file /etc/group changes. So when this change occurs to the line containing demouser, a notification mail should be send, along with the details of the process that made this change. Is it possible?
What operating system?