[Linux]
cat /proc/stat 2>/dev/null | head -1 | \
        awk '{sum=$2+$3+$4+$5; printf("%d %d %d
%d",$2*100/sum,$3*100/sum,$4*100/sum,$5*100/sum)}'

## user% nice% system% idle% 

좋지 않은 데이터가 나옴