10月16日任务

9.1 正则介绍_grep上

9.2 grep中

9.3 grep下

 

grep基本用法

grep [-cinvABC] 'word' filename

• centos7.x版本的grep实则为grep --color=auto
• -c 显示匹配到的行数

[root@localhost ~]# cp /etc/passwd /tmp[root@localhost ~]# cd /tmp[root@localhost tmp]# [root@centos7 tmp]# grep -c 'root' passwd 2

• -i 忽略大小写

[root@centos7 tmp]# grep -i castiel passwdcastiel:x:1000:1000::/home/castiel:/bin/bashCastiel:X:1000:1000::/home/castiel:/bin/bash

• -n 显示匹配行的同时显示行号

[root@centos7 tmp]# grep -n 'root' passwd1:root:x:0:0:root:/root:/bin/bash10:operator:x:11:0:operator:/root:/sbin/nologin

• -v 对匹配信息取反

[root@centos7 tmp]# grep -iv castiel passwdroot:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin.....

• -r 递归匹配过滤（对目录进行操作）

[root@centos7 tmp]# grep -r 'root' /etc/etc/pki/ca-trust/ca-legacy.conf:# The upstream Mozilla.org project tests all changes to the root CA/etc/pki/ca-trust/ca-legacy.conf:# to temporarily keep certain (legacy) root CA certificates trusted,/etc/pki/ca-trust/ca-legacy.conf:#   It may keep root CA certificate as trusted, which the upstream /etc/pki/ca-trust/extracted/README:root CA certificates./etc/pki/ca-trust/extracted/java/README:root CA certificates.匹配到二进制文件 /etc/pki/ca-trust/extracted/java/cacerts/etc/pki/ca-trust/extracted/openssl/README:root CA certificates./etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt:# Comodo AAA Services root/etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt:# Comodo Secure Services root/etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt:# Comodo Trusted Services root

• -An(after) 显示匹配行及其后n行

[root@centos7 tmp]# grep -A2 'root' passwdroot:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologin--operator:x:11:0:operator:/root:/sbin/nologingames:x:12:100:games:/usr/games:/sbin/nologinftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

• -Bn(before) 显示匹配行及其前n行

[root@centos7 tmp]# grep -B2 'root' passwdroot:x:0:0:root:/root:/bin/bash--halt:x:7:0:halt:/sbin:/sbin/haltmail:x:8:12:mail:/var/spool/mail:/sbin/nologinoperator:x:11:0:operator:/root:/sbin/nologin

• -Cn 显示匹配行及其前后n行

[root@centos7 tmp]# grep -C2 'root' passwdroot:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologin--halt:x:7:0:halt:/sbin:/sbin/haltmail:x:8:12:mail:/var/spool/mail:/sbin/nologinoperator:x:11:0:operator:/root:/sbin/nologingames:x:12:100:games:/usr/games:/sbin/nologinftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

正则

# 测试内容[root@localhost ~]# cat test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin111111111111111111111111111111aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa#abcskhd

• 数字 [0-9]

[root@localhost ~]# grep '[0-9]' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin111111111111111111111111111111

• 字母 [a-zA-Z]

[root@localhost ~]# grep '[a-zA-Z]' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologinaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa#abcskhd

• 取反 [^] (在方括号内才表示取反)

[root@localhost ~]# grep '[^a-zA-Z]' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin111111111111111111111111111111#abcskhd

• 开头 ^

[root@localhost ~]# grep '^#' test.txt #abcskhd

• 结尾 $

[root@localhost ~]# grep 'in$' test.txt bin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

• 匹配任意1个字符 .

[root@localhost ~]# grep 'b.n' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

• 匹配0或多个之前的一个字符 *

[root@localhost ~]# grep 'a*m' test.txt daemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologin

扩展正则（grep -E 或 egrep）

• 匹配1或多个之前的一个字符 +

[root@localhost ~]# grep -E 'ro+t' test.txt root:x:0:0:root:/root:/bin/bash

• 匹配花括号之前那个字符的个数 {n} 或 {n, m}

[root@localhost ~]# grep -E 'o{2}' test.txt root:x:0:0:root:/root:/bin/bashlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin[root@localhost ~]# grep -E 'o{1,2}' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

• 匹配0或1个之前的字符 ?

# 匹配0或1个字符o[root@localhost ~]# grep -E 'oo?' test.txt root:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

• 匹配其中之一个表达式：|

[root@localhost ~]# grep -E '111|aaa' test.txt111111111111111111111111111111aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

实用grep实例

• 过滤注释行 grep -v '^#'
• 过滤空行 grep -v '^$'
• 过滤手机号 grep -E '+86-[0-9]{11}'

[root@centos7 tmp]# echo "+86-15301203401" | grep -E '+86-[0-9]{11}' +86-15301203401

• 过滤邮箱 grep -E '\.\*@\.\*\.\.\*'

[root@centos7 tmp]# echo "12ab3#@123@qq.com" | grep -E '.*@.*\..*'12ab3#@123@qq.com[root@centos7 tmp]# echo "12323@163.com" | grep -E '.*@.*\..*'12323@163.com

• 过滤出/etc目录下，包含root字符的所有的.conf文件内的行！--include

[root@centos7 tmp]# grep -r --include="*.conf" 'root' /etc/etc/pki/ca-trust/ca-legacy.conf:# The upstream Mozilla.org project tests all changes to the root CA/etc/pki/ca-trust/ca-legacy.conf:# to temporarily keep certain (legacy) root CA certificates trusted,/etc/pki/ca-trust/ca-legacy.conf:#   It may keep root CA certificate as trusted, which the upstream /etc/yum/pluginconf.d/fastestmirror.conf:# as root)./etc/selinux/semanage.conf:ignoredirs=/root/etc/dbus-1/system.d/teamd.conf:	
    
     /etc/dbus-1/system.d/org.freedesktop.hostname1.conf:        
     
      /etc/dbus-1/system.d/org.freedesktop.import1.conf:        
      
       /etc/dbus-1/system.d/org.freedesktop.locale1.conf:        
       
        ......
       
      
     
    

• 扩展正则 ( ) 的应用

[root@localhost ~]# grep -E 'a(e|d)m' test.txtdaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologin