When I run top -n 1 -d 2 | head -n 12; it returns processor usage for some processes sorted by %cpu desc as desired, but I'm not convinced that the results are aggregated as they should be. I'm wanting to put these results in a file maybe like
while true; do
top -n 1 -d 2 | head -n 12;
done > top_cpu_users;
When I run top -d 2; interactively, I first see some results, then two seconds later I see the results updated and they appear to be aggregated over the last two seconds. The first results do not appear to be aggregated in the same way.
How do I get top cpu users every two seconds aggregated over the previous two seconds?
top will always capture a first full scan of process info for use as a baseline. It uses that to initialize the utility's database of values used for later comparative reporting. That is the basis of the first report presented to the screen.
The follow-on reports are the true measures for the specified evaluation intervals.
Your code snippet will therefore never provide what you are really looking for.
You need to skip the results from the first scan and only use the follow on reports, but the only way to do that is to generate them from a single command by specifying the count of scans desired, then parse the resulting combined report.
To that end, here is a proposed solution:
The session output for that will look like this: