How do I find out a server's load?

I'm creating a php script that will capture certain information from the server and database at regular intervals. The server is running LAMP.

Is there a way to output the server load, or other statistics that may i开发者_C百科ndicate the performance or load on the server including mysql?

Just try

cat /proc/loadavg

or

uptime

which printout the current load of the servers 1 min / 10 min / 15 min interval.

May be you should take a look to http://munin-monitoring.org/ or may be nagios