Linux System Users activity monitoring tool(s)

Can anyone please suggest me opensource tools to monitor users a开发者_运维百科ctivity on any of the linux servers(Redhat/CentOS). My goal is to get a report via email everyday what users logged on the server and what changes they made. I know tripwire and psacct but want to get more options keeping in mind about system performance too..

Thanks Ramesh

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As a starter, Checkout logwatch it comes with Fedora, should be easy to add if not in your distro

If you want trending/graphing i'd suggest munin it is easy to add new modules and write your own, well, easier then doing rrdtool yourself atleast.

if you want to track file changes you can cron up something like

find files modifed in the last 7 days

find . -mtime -7

find files modified in the last 30 minutes

find . -mmin -30