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10月16日任務

9.1 正則介紹_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實則為grep --color=auto
• -c 顯示匹配到的行數

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

• -i 忽略大小寫

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

• -n 顯示匹配行的同時顯示行號

[root@centos7 tmp]# grep -n 'root' passwd 1:root:x:0:0:root:/root:/bin/bash 10:operator:x:11:0:operator:/root:/sbin/nologin

• -v 對匹配信息取反

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

• -r 遞歸匹配過濾（對目錄進行操作）

[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. 匹配到二進制文件 /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) 顯示匹配行及其后n行

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

• -Bn(before) 顯示匹配行及其前n行

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

• -Cn 顯示匹配行及其前后n行

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

正則

# 測試內容 [root@localhost ~]# cat test.txt root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin 111111111111111111111111111111aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa #abcskhd

• 數字?[0-9]

[root@localhost ~]# grep '[0-9]' test.txt root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin 111111111111111111111111111111

• 字母?[a-zA-Z]

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

• 取反?[^]?(在方括號內才表示取反)

[root@localhost ~]# grep '[^a-zA-Z]' test.txt root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin 111111111111111111111111111111 #abcskhd

• 開頭?^

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

• 結尾?$

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

• 匹配任意1個字符?.

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

• 匹配0或多個之前的一個字符 *

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

擴展正則（grep -E 或 egrep）

• 匹配1或多個之前的一個字符?+

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

• 匹配花括號之前那個字符的個數?{n}?或?{n, m}

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

• 匹配0或1個之前的字符??

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

• 匹配其中之一個表達式：|

[root@localhost ~]# grep -E '111|aaa' test.txt 111111111111111111111111111111 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

實用grep實例

• 過濾注釋行?grep -v '^#'
• 過濾空行?grep -v '^$'
• 過濾手機號?grep -E '+86-[0-9]{11}'

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

• 過濾郵箱?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

• 過濾出/etc目錄下，包含root字符的所有的.conf文件內的行！--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: <policy user="root"> /etc/dbus-1/system.d/org.freedesktop.hostname1.conf: <policy user="root"> /etc/dbus-1/system.d/org.freedesktop.import1.conf: <policy user="root"> /etc/dbus-1/system.d/org.freedesktop.locale1.conf: <policy user="root"> ......

• 擴展正則?( )?的應用

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

轉載于:https://my.oschina.net/u/3964535/blog/2246817

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