You could use the Splunk App for Unix and Linux as it has scripts to do exactly this. Otherwise, you can replicate part of the functions by writing a script that captures this info using ps, sar, or another unix tool. Have that script use logger or the equivalent to send the results to a log file. Then either via syslog or a Splunk Forwarder, have that log file sent to your Splunk indexer. That's all you need to do!