Linux grep技巧 删除含有指定关键词的行，创建新文件

一. 需求

⏹有如下文件，现要求

• 删除含有xuecheng关键字的行
• 删除含有192.168.1.1关键字的行
• 也就是说，最终只会留下127.0.0.1 license.sublimehq.com

127.0.0.1 www.xuecheng.com
127.0.0.1 img.xuecheng.com
192.168.1.1 www.test.com
127.0.0.1 video.xuecheng.com
127.0.0.1 teacher.xuecheng.com
127.0.0.1 system.xuecheng.com
127.0.0.1 ucenter.xuecheng.com
127.0.0.1 license.sublimehq.com

二. grep -v 排除

⏹方式1

• -E：用来指定正则表达式
• -v：用来排除

grep -E "xuecheng|192.168.1.1" -v ./hosts

# 查看hosts文件内容
fengyehong@ubuntu:~/jmw_work_space/20240625$ cat hosts
127.0.0.1 www.xuecheng.com
127.0.0.1 img.xuecheng.com
192.168.1.1 www.test.com
127.0.0.1 video.xuecheng.com
127.0.0.1 teacher.xuecheng.com
127.0.0.1 system.xuecheng.com
127.0.0.1 ucenter.xuecheng.com
127.0.0.1 license.sublimehq.com

# 排除指定的行
fengyehong@ubuntu:~/jmw_work_space/20240625$ grep -E "xuecheng|192.168.1.1" -v ./hosts
127.0.0.1 license.sublimehq.com

⏹方式2

grep -v "xuecheng" ./hosts | grep -v "192.168.1.1"

# 查看hosts文件内容
fengyehong@ubuntu:~/jmw_work_space/20240625$ cat hosts
127.0.0.1 www.xuecheng.com
127.0.0.1 img.xuecheng.com
192.168.1.1 www.test.com
127.0.0.1 video.xuecheng.com
127.0.0.1 teacher.xuecheng.com
127.0.0.1 system.xuecheng.com
127.0.0.1 ucenter.xuecheng.com
127.0.0.1 license.sublimehq.com

# 先使用-v排除掉xuecheng关键字之后,再使用-v排除192.168.1.1关键字
fengyehong@ubuntu:~/jmw_work_space/20240625$ grep -v "xuecheng" ./hosts | grep -v "192.168.1.1"
127.0.0.1 license.sublimehq.com

三. 创建新文件

grep -v "xuecheng" ./hosts | grep -v "192.168.1.1" > new_hosts