在 Ubuntu 20.04.3 上，调用ps -e -o args,pid,etime,%cpu,%mem --forest | egrep "firefox|PID" | grep -v grep给出以下结果：
COMMAND PID ELAPSED %CPU %MEM
\_ /usr/lib/firefox/firefo 5730 01:58:40 20.8 4.9
| \_ /usr/lib/firefox/fi 5811 01:58:39 0.0 0.2
| \_ /usr/lib/firefox/fi 5841 01:58:39 0.1 0.7
| \_ /usr/lib/firefox/fi 5895 01:58:39 0.0 0.9
| \_ /usr/lib/firefox/fi 5926 01:58:39 4.3 2.0
| \_ /usr/lib/firefox/fi 6000 01:58:38 21.7 2.0
| \_ /usr/lib/firefox/fi 6094 01:58:32 4.2 0.3
| \_ /usr/lib/firefox/fi 7004 01:54:00 1.4 2.0
| \_ /usr/lib/firefox/fi …