I want a script to tell me the average CPU usage over the past 5 minutes (and repeat every 5 minutes, likely as a cron job).
/proc/stat just has counters since system start, and I want to avoid developing a full program to parse and sample that.
top seems to just report usage over the moment (second?) before it displays/writes the table.
sysstat/sar looks promising, but looks like I'll always loose the midnight value looking at what
sar -u gives me...