I've been asked to grab the CPU usage for individual cores using mpstat. I can get all the information I need for each an individual CPU like so:
mpstat -P 0
Which gives the following output:
Linux 3.10.0-957.21.3.el7.x86_64 (cpu_devel) 03/16/2021 _x86_64_ (48 CPU)
09:59:32 AM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
09:59:32 AM 0 0.05 0.00 0.05 0.00 0.00 0.01 0.00 0.00 0.00 99.89
What I need to do is grab the number under idle (99.89) and subtract that from 100 to get the total CPU usage. I was trying to grab the 12th field with a delimiter of spaces like this:
mpstat -P 0 | cut -d' ' -f12
But that showed me that there are actually multiple spaces between each field. So I'm looking for help to find a cleaner solution!
You could simply do this with awk. Simply pass your command(mpstat) output as a standard input to awk command as an input; then in main program of awk look if the line number is 4th line then print last column of that line(with checking a condition if $NF is greater than 0 then subtract it with 100 else print it as it is).
mpstat -P 0 | awk 'FNR==4{print ($NF>0?100-$NF:$NF)}'