作業四：查詢firewall進程，然后殺死
[root@localhost 桌面]# ps -aux |grep firewall
root??????? 772? 0.0? 2.0 327912 20704 ???????? Ssl? 15:23?? 0:00 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
root?????? 5323? 0.0? 0.0 112660?? 996 pts/0??? R+?? 16:46?? 0:00 grep --color=auto firewall
[root@localhost 桌面]# kill -9 772
[root@localhost 桌面]# ps -aux |grep firewall
root?????? 5521? 0.0? 0.0 112656?? 996 pts/0??? R+?? 17:01?? 0:00 grep --color=auto firewall
...)