正则+shell初学

家人们谁懂啊啊 疯狂赶进度

1. 文本处理工具

cat head tail 结合使用
cxn@ubuntu2204:~$ cat aaa.txt
Nov 13 03:17:56 pbzjack sshd[1464]: Connection closed by 112.4.65.118 port 45206 [preauth]
Nov 13 03:18:04 pbzjack sshd[1522]: Invalid user ubuntu from 110.42.234.146 port 52268
Nov 13 03:18:04 pbzjack sshd[1522]: input_userauth_request: invalid user ubuntu [preauth]
Nov 13 03:18:04 pbzjack sshd[1522]: Received disconnect from 110.42.234.146 port 52268:11: Bye Bye [preauth]
Nov 13 03:18:04 pbzjack sshd[1522]: Disconnected from 110.42.234.146 port 52268 [preauth]
Nov 13 03:19:10 pbzjack sshd[1760]: Invalid user redhat from 159.223.87.87 port 34400
Nov 13 03:19:10 pbzjack sshd[1760]: input_userauth_request: invalid user redhat [preauth]
Nov 13 03:19:10 pbzjack sshd[1760]: Connection closed by 159.223.87.87 port 34400 [preauth]
Nov 13 03:20:04 pbzjack sshd[