Not sure what you are trying to do here? The show log command will give you the information based on what level you set it at. If you set it at informational for instance your log will show from level 0 to that level. Can't remember what it is off the top of my head..i think it's level 6? Anyways, set up a syslog server and have your log sent to it. Once you do that your syslog server can then make sense of the logs and shoot out alerts based on that.
Otherwise you just have to know how to read them. They get more complicated once you start adding ACLs and port security as this produces much more log info.
