計算系統運行時間

cat /proc/uptime| awk -F. '{run_days=$1 / 86400;run_hour=($1 % 86400)/3600;run_minute=($1 % 3600)/60;run_second=$1 % 60;printf("running time: %d Day %d Hours %d Mins %d Secs \n",run_days,run_hour,run_minute,run_second)}'