使用信号控制进程
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kill,killall,pkill,top
kill，killall，pkill：都能发送信号。
kill 只能接进程号
killall 能接进程名称
pkill 可以删除某个终端，或者某个用户的进程
pkill -t pst/2
pkill -9 -t pst/2
pkill -u test01
pkill -19 -u test01
给进程发送信号
[root@localhost ~]# kill -l //列出所有支持的信号
编号 信号名
1) SIGHUP 重新加载配置，信号发出之后，主进程的进程号不会发生变化，子进程进程号会发生变化。
[root@ds2 conf.d]# ps -ef |grep nginx root 27618 1 0 18:16 ? 00:00:00 nginx: master process /opt/data/nginx/sbin/nginx -c /opt/data/nginx/conf/nginx.conf nginx 27619 27618 0 18:16 ? 00:00:00 nginx: worker process root 27754 18508 0 19:26 pts/1 00:00:00 grep --color=auto nginx [root@ds2 conf.d]# kill -1 27618 [root@ds2 conf.d]# ps -ef |grep nginx root 27618 1 0 18:16 ? 00:00:00 nginx: master process /opt/data/nginx/sbin/nginx -c /opt/data/nginx/conf/nginx.conf nginx 27755 27618 0 19:27 ? 00:00:00 nginx: worker process root 27757 18508 0 19:27 pts/1 00:00:00 grep --color=auto nginx
2) SIGINT 键盘中断^C
[root@ds2 ~]# ps -ef |grep ping root 27786 18508 0 19:32 pts/1 00:00:00 ping 192.168.42.177 root 27788 27764 0 19:32 pts/0 00:00:00 grep --color=auto ping [root@ds2 ~]# kill -2 27786 [root@ds2 ~]# ps -ef |grep ping root 27790 27764 0 19:33 pts/0 00:00:00 grep --color=auto ping
3) SIGQUIT 键盘退出
9) SIGKILL 强制终止
15) SIGTERM 终止（正常结束），缺省信号
18) SIGCONT 继续
19) SIGSTOP 停止
20)SIGTSTP 暂停^Z
作业1： 给vsftpd进程发送信号1,15
[root@localhost ~]# ps aux |grep vsftpd
root 9160 0.0 0.0 52580 904 ? Ss 21:54 0:00 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
[root@localhost ~]# kill -1 9160 //发送重启信号
root 9160 0.0 0.0 52580 904 ? Ss 21:54 0:00 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
[root@localhost ~]# kill 9160 //发送停止信号 （默认就是15信号）
[root@localhost ~]# ps aux |grep vsftpd
//1
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ ps aux |grep crond
root 478 0.0 0.1 124144 1572 ? Ss 09:35 0:00 /usr/sbin/crond -n
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ sudo kill -1 478
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ ps aux |grep crond
root 478 0.0 0.1 124144 1572 ? Ss 09:35 0:00 /usr/sbin/crond -n
//15
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ sudo kill 478
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ ps aux |grep crond
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ sudo systemctl start crond
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ ps aux |grep crond
root 22319 0.0 0.1 124140 1548 ? Ss 14:54 0:00 /usr/sbin/crond -n
作业2：信号测试9,15
[root@localhost ~]# touch file1 file2
[root@localhost ~]# tty
/dev/pts/1
[root@localhost ~]# vim file1
[root@localhost ~]# tty
/dev/pts/2
[root@localhost ~]# vim file2
[root@localhost ~]# ps aux |grep vim
root 4362 0.0 0.2 11104 2888 pts/1 S+ 23:02 0:00 vim file1
root 4363 0.1 0.2 11068 2948 pts/2 S+ 23:02 0:00 vim file2
[root@localhost ~]# kill 4362
[root@localhost ~]# kill -9 4363
[root@localhost ~]# killall vim //给所有vim进程发送信号
[root@localhost ~]# killall httpd
作业3：信号测试18,19
[root@ds2 ~]# ps aux |grep nginx root 27854 0.0 0.1 48112 1144 ? Ss 19:48 0:00 nginx: master process /opt/data/nginx/sbin/nginx -c /opt/data/nginx/conf/nginx.conf nginx 27855 0.0 0.2 48492 2168 ? S 19:48 0:00 nginx: worker process root 27878 0.0 0.0 112728 972 pts/1 S+ 19:49 0:00 grep --color=auto nginx [root@ds2 ~]# kill -19 27854 [root@ds2 ~]# ps aux |grep nginx root 27854 0.0 0.1 48112 1144 ? Ts 19:48 0:00 nginx: master process /opt/data/nginx/sbin/nginx -c /opt/data/nginx/conf/nginx.conf nginx 27855 0.0 0.2 48492 2168 ? S 19:48 0:00 nginx: worker process root 27880 0.0 0.0 112728 972 pts/1 R+ 19:50 0:00 grep --color=auto nginx [root@ds2 ~]# kill -18 27854 [root@ds2 ~]# ps aux |grep nginx root 27854 0.0 0.1 48112 1144 ? Ss 19:48 0:00 nginx: master process /opt/data/nginx/sbin/nginx -c /opt/data/nginx/conf/nginx.conf nginx 27855 0.0 0.2 48492 2168 ? S 19:48 0:00 nginx: worker process root 27882 0.0 0.0 112728 972 pts/1 S+ 19:50 0:00 grep --color=auto nginx
作业4：踢出一个从远程登录到本机的用户
[root@localhost ~]# pkill --help
pkill: invalid option -- '-'
Usage: pkill [-SIGNAL] [-fvx] [-n|-o] [-P PPIDLIST] [-g PGRPLIST] [-s SIDLIST]
[-u EUIDLIST] [-U UIDLIST] [-G GIDLIST] [-t TERMLIST] [PATTERN]
[root@localhost ~]# pkill -u alice
[root@localhost ~]# w
15:46:44 up 2:19, 4 users, load average: 0.17, 0.12, 0.08
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root tty1 :0 21:32 ? 4:22 4:22 /usr/bin/Xorg :
root pts/0 :0.0 15:46 0.00s 0.00s 0.00s w
root pts/3 172.16.8.100 15:46 2.00s 0.01s 0.00s sleep 50000
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ w
15:17:25 up 5:42, 3 users, load average: 0.00, 0.01, 0.05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
yang pts/0 123.120.22.32 15:00 21.00s 0.00s 0.00s -bash
yang pts/1 123.120.22.32 15:00 5.00s 0.00s 0.00s w
yang pts/2 123.120.22.32 12:04 13.00s 0.12s 0.02s vim file1
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ pkill -t pts/2 //终止pts/2上所有进程
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ pkill -9 -t pts/2 //终止pts/2上所有进程 并结束该pts/2
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ w
15:20:59 up 5:45, 3 users, load average: 0.00, 0.01, 0.05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
yang pts/0 123.120.22.32 15:00 3:55 0.00s 0.00s -bash
yang pts/1 123.120.22.32 15:00 3.00s 0.01s 0.00s w
yang pts/2 123.120.22.32 15:20 3.00s 0.00s 0.00s -bash
[yang@iZm5eiwihahzq6ds23gbf6Z ~]$ sudo pkill -u yang