Linux5.5 正则

正则:一串有规律的字符串 

grep命令

  grep可以实现的,egrep都可以实现。

  grep    [-cinvrABC]   'word'   filename【自带color选项】

#无任何选项
[root@chy002 tmp]# grep 'root' passwd.txt
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

  -c 行数

[root@chy002 tmp]# grep -c 'root' passwd.txt
2

  -i  不区分大小写

[root@chy002 tmp]# grep -i 'root' passwd.txt
ROOt
ROOT
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

  -n  显示行号

[root@chy002 tmp]# grep -in 'root' passwd.txt
1:ROOt
2:ROOT
3:root:x:0:0:root:/root:/bin/bash
12:operator:x:11:0:operator:/root:/sbin/nologin

  -v  取反

#不带nologin行过滤
[root@chy002 tmp]# grep -vni 'nologin' passwd.txt
1:ROOt
2:ROOT
3:root:x:0:0:root:/root:/bin/bash
8:sync:x:5:0:sync:/sbin:/bin/sync
9:shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
10:halt:x:7:0:halt:/sbin:/sbin/halt
22:chy002:x:1000:1000::/home/chy002:/bin/bash
23:user:x:1001:1001::/home/user:/bin/bash
24:user1:x:1002:1006::/home/user1:/bin/bash
25:user2:x:1004:1002::/home/user2:/bin/bash
26:user3:x:1005:1002::/tmp/user3:/bin/bash
27:user4:x:1009:1006::/home/user5:/bin/bash

  -r  遍历所有子目录

[root@chy002 tmp]# grep -in 'root' /tmp/
grep: /tmp/: 是一个目录
[root@chy002 tmp]# grep -rin 'root' /tmp/
/tmp/123.txt:1:root:x:0:0:root:/root:/bin/bash
/tmp/123.txt:10:operator:x:11:0:operator:/root:/sbin/nologin
/tmp/321.txt:1:root:x:0:0:root:/root:/bin/bash
/tmp/321.txt:10:operator:x:11:0:operator:/root:/sbin/nologin
/tmp/passwd.txt:1:ROOt
/tmp/passwd.txt:2:ROOT
/tmp/passwd.txt:3:root:x:0:0:root:/root:/bin/bash
/tmp/passwd.txt:12:operator:x:11:0:operator:/root:/sbin/nologin
... ...

  -A  后面跟数字过滤出符合要求的行以及下面n行

[root@chy002 tmp]# grep -nA2 'root' passwd.txt
3:root:x:0:0:root:/root:/bin/bash
4-bin:x:1:1:bin:/bin:/sbin/nologin
5-daemon:x:2:2:daemon:/sbin:/sbin/nologin
--
12:operator:x:11:0:operator:/root:/sbin/nologin
13-games:x:12:100:games:/usr/games:/sbin/nologin
14-ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

  -B   过滤出符合要求的行及上面的n行

  -C  同时过滤出符合要求的行及上下各n行

       [0-9a-zA-Z]

[root@chy002 tmp]# grep -nv '[0-9]' passwd.txt
1:ROOt
2:ROOT

  [^]  非的意思

#匹配非小写字母开头的行
[root@chy002 tmp]# grep -n '^[^a-z]' passwd.txt
1:ROOt
2:ROOT

  [^$]  空行

#去除文本中的空行
[root@chy002 tmp]# grep -nv '^$' 1.txt
1:sadf
2:123
4:qwe123
6:Q2

  o*o  表示*号左边的字符重复0-n次,一定匹配右边一个字符o

[root@chy002 tmp]# grep -n 'r*o' passwd.txt
2:roooooo
3:ro
8:root:x:0:0:root:/root:/bin/bash
9:bin:x:1:1:bin:/bin:/sbin/nologin
10:daemon:x:2:2:daemon:/sbin:/sbin/nologin
... ...

  r.o   r和o中间任意一个字符,必须有一个

[root@chy002 tmp]# grep -n 'r.o' passwd.txt
2:roooooo
8:root:x:0:0:root:/root:/bin/bash
17:operator:x:11:0:operator:/root:/sbin/nologin

  .*   匹配全部,包含所有字符及空行

  

  { }  花括号,使用egrep或者 -E 可以不使用脱义符号

[root@chy002 tmp]# grep 'o{2}' passwd.txt
o{2}
[root@chy002 tmp]# grep 'o{2}' passwd.txt
roooooo
root:x:0:0:root:/root:/bin/bash
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin

  o+b  b前面1次或者多次o,必须b紧挨着o,加号还是需要脱义,可以使用egrep 或 -E 

[root@chy002 tmp]# grep 'o+t' passwd.txt
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

  o?b  b前面o重复次数0或者1,只要有一个b就能匹配

[root@chyuanliu-01 tmp]# grep 'o?b' 123.txt
robt
ro123bt
roobt
roobbt
robobt
rbt
orbt

  |   或者符号

[root@chyuanliu-01 tmp]# grep 'root|nologin' passwd.txt
root:x:0:0:root:/root:/bin/bash
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin

sed命令

  sed关键在于替换,与grep匹配最主要的区别在于能对匹配的字符进行删除更改等操作,无color选项。

  匹配打印指定行,-n 只打印符合规则,p打印

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '10'p text.txt
operator:x:11:0:operator:/root:/sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# wc -l text.txt
28 text.txt
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '10,14'p text.txt
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
nobody:x:99:99:Nobody:/:/sbin/nologin
systemd-bus-proxy:x:999:998:systemd Bus Proxy:/:/sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '/root/'p text.txt
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

   不区分大小写进行打印,I 不区分大小写

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '/root/'Ip text.txt
root:x:0:0:root:/root:/bin/bash
ROOT:
operator:x:11:0:operator:/root:/sbin/nologin

   |或者

[root@localhost tmp]# sed -nr '/root|home/'p passwd
#root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
mysql:x:1000:1000::/home/mysql:/bin/bash
php-fpm:x:1001:1001::/home/php-fpm:/sbin/nologin
user:x:1002:1002::/home/user:/bin/bash 

  同时执行多个任务,-e  同时执行

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -e '/root/'Ip -e'/ftp/'p -n text.txt
root:x:0:0:root:/root:/bin/bash
ROOT:
operator:x:11:0:operator:/root:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin 
[root@localhost tmp]# sed -e '1'p -e '/home/'p -n passwd
#root:x:0:0:root:/root:/bin/bash
mysql:x:1000:1000::/home/mysql:/bin/bash
php-fpm:x:1001:1001::/home/php-fpm:/sbin/nologin
user:x:1002:1002::/home/user:/bin/bash
[root@localhost tmp]# sed -e '1'p -e '/root/'p -n passwd
#root:x:0:0:root:/root:/bin/bash
#root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

  打印全部,1,$

[root@localhost tmp]# sed -n '1,$'p 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
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sb
.......

  脱意  -r  不识别  +|{}()

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '/ro+/'p text.txt
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
systemd-bus-proxy:x:999:998:systemd Bus Proxy:/:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
chrony:x:997:995::/var/lib/chrony:/sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '/ro+/'p text.txt
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -nr '/ro+/'p text.txt
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
systemd-bus-proxy:x:999:998:systemd Bus Proxy:/:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
chrony:x:997:995::/var/lib/chrony:/sbin/nologin

   打印某行到某行之间

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '/mysql/,/admin/'p text.txt
mysql:x:1001:1001::/home/mysql:/sbin/nologin
www:x:1002:1002::/home/www:/bin/bash
admin:x:1003:1003::/home/admin:/bin/bash

  删除指定行,不会在原文件上修改,若需要修改要加  -i 选项

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -e '/www/'d -e  '/mysql/'d text.txt
... ...
tcpdump:x:72:72::/:/sbin/nologin
admin:x:1003:1003::/home/admin:/bin/bash
chyuanliuNJ:x:1004:1004::/home/chyuanliuNJ:/bin/bash
#删除含有www 和 mysql的行,如果加上-n不会输出任何东西,因为-n只打印命令中的指令

   替换,选项s  为替换   g  为全局。也可以作为删除选项

[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '27,28s/www/WWW/g'p text.txt
WWW:x:1002:1002::/home/WWW:/bin/bash
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -n '27,28s/[0-9]//g'p text.txt
www:x::::/home/www:/bin/bash
admin:x::::/home/admin:/bin/bash

   如果遇到多斜杠替换,可以把sed的斜杠操作符换成#等等

#替换test.txt中 ‘/sbin/nologin’ 为 ‘/bin/login’
[root@chyuanliuNJ awk]# sed -n '5,8s#sbin/nologin#bin/login#g'p text.txt
bin:x:1:1:bin:/bin:/bin/login
bin:x:1:1:bin:/bin:/bin/login

  调换位置,下面的 1可以换成&,&确切含义是前一对/ /内全部内容

[root@localhost tmp]# head -2 passwd |sed -nr 's/(.*)/chyuanliu:&/'p
chyuanliu:#root:x:0:0:root:/root:/bin/bash
chyuanliu:#bin:x:1:1:bin:/bin:/sbin/nologin
#在每行之前加字符
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -nr '1,2s/(.*)/chyuanliu:1/'p text.txt
chyuanliu:root:x:0:0:root:/root:/bin/bash
chyuanliu:ROOT:
#在每行最后加字符
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -nr '1,2s/(.*)/1chyuanliu:/'p text.txt
root:x:0:0:root:/root:/bin/bashchyuanliu:
ROOT:chyuanliu:
#调换第一项和最后一项
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -nr '18,20'p text.txt
polkitd:x:998:997:User for polkitd:/:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# sed -nr '18,20s/([^:]+):(.*):([^:]+)/3:2:1/'p text.txt
/sbin/nologin:x:998:997:User for polkitd:/:polkitd
/sbin/nologin:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:tss
/sbin/nologin:x:74:74:Privilege-separated SSH:/var/empty/sshd:sshd

awk命令

可以分段操作,不能更改文件内容。可用正则符号,不用脱意

  截取文档中某段,-F指定分隔符

[root@izbp1gcpbwpui5pfbnjbhyz awk]# tail -n5 text.txt | awk -F ':' '{print $1}'
tcpdump
mysql
www
admin
chyuanliuNJ
[root@izbp1gcpbwpui5pfbnjbhyz awk]# tail -n5 text.txt | awk -F ':' '{print $0}'
tcpdump:x:72:72::/:/sbin/nologin
mysql:x:1001:1001::/home/mysql:/sbin/nologin
www:x:1002:1002::/home/www:/bin/bash
admin:x:1003:1003::/home/admin:/bin/bash
chyuanliuNJ:x:1004:1004::/home/chyuanliuNJ:/bin/bash

   截取并自定义输出链接符,定义的链接符写着输出前

[root@izbp1gcpbwpui5pfbnjbhyz awk]# tail -n5 text.txt | awk -F ':' '{print $1,$2,$3}'
tcpdump x 72
mysql x 1001
www x 1002
admin x 1003
chyuanliuNJ x 1004
[root@izbp1gcpbwpui5pfbnjbhyz awk]# tail -n5 text.txt | awk -F ':' '{OFS="#"} {print $1,$2,$3}'
tcpdump#x#72
mysql#x#1001
www#x#1002
admin#x#1003
chyuanliuNJ#x#1004
[root@chyuanliuNJ awk]# awk -F ":" '{print $1"#"$2}' text.txt
root#x
root#x
ROOT#x
ROOT#x
... ...

  针对某个字段匹配

#全文匹配
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk '/oo+/'
root:x:0:0:root:/root:/bin/bash
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
#只针对第五段进行匹配
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' '$5 ~ /oo+/'
root:x:0:0:root:/root:/bin/bash
[root@izbp1gcpbwpui5pfbnjbhyz awk]# awk -F ':' '/root/ {print $1,$3}; $1 ~/admin/ {print "Sec!!"$0}; $3 ~/5/ {print "Thri!!"$0}' text.txt
root 0
Thri!!sync:x:5:0:sync:/sbin:/bin/sync
operator 11
Thri!!tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
Sec!!admin:x:1003:1003::/home/admin:/bin/bash

   条件操作符

#与ASCII字符比较
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' '$3>"5"'
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
#与数字大小比较
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' '$3>5'
ROOT:x:23
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' '$3>5 && $3<7'
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' '$3>1 && $7=="/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
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
[root@chyuanliuNJ awk]# awk -F ':' '{OFS="#"}{if($3>1000){print $1,$2,$3,$4}                    }' text.txt
mysql#x#1001#1001
mysql#x#1001#1001
www#x#1002#1002
www#x#1002#1002
admin#x#1003#1003
admin#x#1003#1003
chyuanliuNJ#x#1004#1004
chyuanliuNJ#x#1004#1004
[root@chyuanliuNJ awk]# awk -F ':' '{OFS="#"} $3>1000 {print $1,$2,$3,$4}' text.txt             mysql#x#1001#1001
mysql#x#1001#1001
www#x#1002#1002
www#x#1002#1002
admin#x#1003#1003
admin#x#1003#1003
chyuanliuNJ#x#1004#1004
chyuanliuNJ#x#1004#1004
#针对数字的比较,加双引号是ASCII码比较,不加是纯数字比较
[root@localhost tmp]# awk -F ':' '{OFS=","} $3>=1000 {print $1,$2,$3}' passwd
mysql,x,1000
php-fpm,x,1001
user,x,1002
[root@localhost tmp]# awk -F ':' '{OFS=","} $3>="1000" {print $1,$2,$3}' passwd
daemon,x,2
adm,x,3
lp,x,4
sync,x,5
shutdown,x,6
... ...
[root@localhost tmp]# awk -F ':' ' $7!="/sbin/nologin" {print $0}' passwd       1#root:x:0:0:root:/root:/bin/bash

sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
ooooooooooooooo
mysql:x:1000:1000::/home/mysql:/bin/bash
user:x:1002:1002::/home/user:/bin/bash

  

  awk内置变量 。NF(段数)NR(行数)

[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n5 text.txt | awk -F ':' '{print NR}'
1
2
3
4
5
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n5 text.txt | awk -F ':' '{print $NR,$NF}'
root /bin/bash
x 23
1 /sbin/nologin
2 /sbin/nologin
adm /sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n5 text.txt | awk -F ':' '{print NR,NF}'
1 7
2 3
3 7
4 7
5 79
[root@izbp1gcpbwpui5pfbnjbhyz awk]# awk 'NR>26' text.txt
www:x:1002:1002::/home/www:/bin/bash
admin:x:1003:1003::/home/admin:/bin/bash
chyuanliuNJ:x:1004:1004::/home/chyuanliuNJ:/bin/bash
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n10 text.txt | awk -F ':' 'NR>=6 && NR<=10 {print NR":"$0}'
6:lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
7:sync:x:5:0:sync:/sbin:/bin/sync
8:shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
9:halt:x:7:0:halt:/sbin:/sbin/halt
10:mail:x:8:12:mail:/var/spool/mail:/sbin/nologin

   计算操作

[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n5 text.txt | awk -F ':' '$1=10 {print $0}'
10 x 0 0 root /root /bin/bash
10 x 23
10 x 1 1 bin /bin /sbin/nologin
10 x 2 2 daemon /sbin /sbin/nologin
10 x 3 4 adm /var/adm /sbin/nologin
[root@izbp1gcpbwpui5pfbnjbhyz awk]# head -n5 text.txt | awk -F ':' '{OFS="##"} {$7=$3+$4} {print $0}'
root##x##0##0##root##/root##0
ROOT##x##23########23
bin##x##1##1##bin##/bin##2
daemon##x##2##2##daemon##/sbin##4
adm##x##3##4##adm##/var/adm##7

   条件关系

[root@izbp1gcpbwpui5pfbnjbhyz awk]# awk -F ':' '{(tmp=tmp+$3)}; END{print tmp}' text.txt
7832
[root@izbp1gcpbwpui5pfbnjbhyz awk]# awk -F ':' '{if($1=="root") print $0}' text.txt
root:x:0:0:root:/root:/bin/bash
原文地址:https://www.cnblogs.com/chyuanliu/p/7857849.html