For a benchmark script, I need to extract the iowait % right after a little operation.
For now, the best way I find was this:
IOWAIT=top -bn2 | awk '$1~/Cpu/ {print $6}' | sed -n '2p' | tr -d '%wa,'
The correct output is something like 2.1:
First, if I didn't precise "-bn2", I don't know why, it is always 0.1% if I take the capture only 1 time. So I take the capture two time, then I awk to get the iowait field then I sed the second line and then I remove the "%wa"
FYI, here is the output of top -bn2 | grep Cpu
Cpu(s): 2.8%us, 0.4%sy, 0.0%ni, 96.6%id, 0.1%wa, 0.0%hi, 0.0%si, 0.0%st<br>
Cpu(s): 0.2%us, 2.9%sy, 0.0%ni, 87.1%id, 9.5%wa, 0.0%hi, 0.3%si, 0.0%st
My problem is the following: when I get one column at 100.0% (for example idle), it's shift the columnnumber so my awk doesn't work anymore and I get the "0.0%hi" field.
My questions is the following:
-How to tell awk to take to column with the "%wa" ?
If anybody have a best approach to what I'm looking to do, I'm of course very open to suggestion !
Thanks
2 ways to do it. You didn't say but I presume you're on linux (that top syntax doesn't work on osx), so this should work with iostat:
iostat -c|awk '/^ /{print $4}'
or with top:
top -bn2| awk -F"," '/Cpu/{if(p==0){p=1}else{split($5,a,"%");print a[1]}}'