grep命令使用

链接：https://www.zhihu.com/question/302368415/answer/1978269918509168079

只涉及初中级的使用

grep "80" /etc/passwd #匹配80的行 模糊查询
grep "^root" /etc/passwd # 匹配以 root 开头的行
grep "txt$" file.txt # 匹配以 txt 结尾的行
grep "a[0-9]" file.txt # 匹配 a 后跟数字

grep -E "error|warning" logfile # 匹配 error 或 warning
grep -E "user[0-9]{2}" file.txt # 匹配 user 后跟两位数字
grep -e "error" -e "fail" logfile
grep -iE "^(root|admin)" file.txt

grep "pattern" file1.txt file2.txt #多文件匹配
grep -H "pattern" *.log #（-H 显示文件名 -h 不显示文件名）

grep -i "root" /etc/passwd #不区分大小写
grep -v "root" /etc/passwd # 反向匹配，找出不匹配root的行

grep -n "pattern" file.txt # 显示行号
grep -C 3 "pattern" file.txt # 显示匹配行及上下 3 行
grep -A 2 "pattern" file.txt # 显示匹配行及后 2 行
grep -B 2 "pattern" file.txt # 显示匹配行及前 2 行

grep -r "80" etc/nginx/conf.d/ # 递归搜索文件夹 输出：
conf.d/minio.conf: #listen [::]:80;
conf.d/minio.conf: #proxy_pass http://192.168.31.80:9001$uri$is_args$args;
conf.d/devicelclient.conf: server_name 192.168.31.80;
conf.d/temp/redmine.conf:# listen 80 ;