Linux通配符和正则表达式

àì夳堔傛蜴生んèń 2022-01-23 06:09 323阅读 0赞

#### **一、 通配符（常用于命令行）：** ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 1]  
单引号和双引号以及反引号

[root@localhost tmp]# echo "date" 
    date
    [root@localhost tmp]# echo "`date`"
    Sun Aug  4 08:26:05 PDT 2019
    [root@localhost tmp]# echo '`date`'
    `date`
    [root@localhost tmp]# echo "$(date)"
    Sun Aug  4 08:27:03 PDT 2019
    [root@localhost tmp]#

\{\} 内容序列

[root@localhost ~]# mkdir {1..10}.txt
    [root@localhost ~]# ll
    total 140
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 10.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 1.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 2.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 3.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 4.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 5.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 6.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 7.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 8.txt
    drwxr-xr-x  2 root root  4096 Aug  4 08:57 9.txt

#### **二、正则表达式** ####

##### 1.什么是正则表达式？ #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 2]

##### 2.为什么要学会正则表达式？ #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 3]

##### 3.容易混淆的注意事项 #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 4]

##### 基础正则表达式，第一波说明： #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 5]原文件内容：  
.\*代表所有

[root@localhost cs]# grep -n ".*" passwd 
    1:root:x:0:0:root:/root:/bin/bash
    2:bin:x:1:1:bin:/bin:/sbin/nologin
    3:
    4:daemon:x:2:2:daemon:/sbin:/sbin/nologin
    5:adm:x:3:4:adm:/var/adm:/sbin/nologin
    6:
    7:lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
    8:sync:x:5:0:sync:/sbin:/bin/sync
    9:shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
    10:
    11:halt:x:7:0:halt:/sbin:/sbin/halt
    12:mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
    13:uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
    14:
    15:
    16:
    17:
    18:operator:x:11:0:operator:/root:/sbin/nologin
    19:games:x:12:100:games:/usr/games:/sbin/nologin
    20:gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
    21:ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
    22:
    23:
    24:
    25:
    26:nobody:x:99:99:Nobody:/:/sbin/nologin
    27:dbus:x:81:81:System message bus:/:/sbin/nologin
    28:usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
    29:vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
    30:rtkit:x:499:497:RealtimeKit:/proc:/sbin/nologin
    31:avahi-autoipd:x:170:170:Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
    32:abrt:x:173:173::/etc/abrt:/sbin/nologin
    33:haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
    34:gdm:x:42:42::/var/lib/gdm:/sbin/nologin
    35:ntp:x:38:38::/etc/ntp:/sbin/nologin
    36:apache:x:48:48:Apache:/var/www:/sbin/nologin
    37:saslauth:x:498:76:"Saslauthd user":/var/empty/saslauth:/sbin/nologin
    38:postfix:x:89:89::/var/spool/postfix:/sbin/nologin
    39:pulse:x:497:496:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
    40:sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
    41:tcpdump:x:72:72::/:/sbin/nologin
    42:xm:x:500:500:xh:/home/xm:/bin/bash
    43:mysql:x:496:493::/home/mysql:/sbin/nologin
    44:nginx:x:495:492::/home/nginx:/sbin/nologin

^root 以root开头  
bash$ 以bash结尾

[root@localhost cs]# grep -n "^root" passwd 
    1:root:x:0:0:root:/root:/bin/bash
    [root@localhost cs]# grep -n "bash$" passwd 
    1:root:x:0:0:root:/root:/bin/bash
    42:xm:x:500:500:xh:/home/xm:/bin/bash

^$ 代表空行

[root@localhost cs]# grep -n "^$" passwd 
    3:
    6:
    10:
    14:
    15:
    16:
    17:
    22:
    23:
    24:
    25:
    [root@localhost cs]#

grep -vn “^$” passwd 代表排除空行

[root@localhost cs]# grep -vn "^$" passwd 
    1:root:x:0:0:root:/root:/bin/bash
    2:bin:x:1:1:bin:/bin:/sbin/nologin
    4:daemon:x:2:2:daemon:/sbin:/sbin/nologin
    5:adm:x:3:4:adm:/var/adm:/sbin/nologin
    7:lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
    8:sync:x:5:0:sync:/sbin:/bin/sync
    9:shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
    11:halt:x:7:0:halt:/sbin:/sbin/halt
    12:mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
    13:uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
    18:operator:x:11:0:operator:/root:/sbin/nologin
    19:games:x:12:100:games:/usr/games:/sbin/nologin
    20:gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
    21:ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
    26:nobody:x:99:99:Nobody:/:/sbin/nologin
    27:dbus:x:81:81:System message bus:/:/sbin/nologin
    28:usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
    29:vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
    30:rtkit:x:499:497:RealtimeKit:/proc:/sbin/nologin
    31:avahi-autoipd:x:170:170:Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
    32:abrt:x:173:173::/etc/abrt:/sbin/nologin
    33:haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
    34:gdm:x:42:42::/var/lib/gdm:/sbin/nologin
    35:ntp:x:38:38::/etc/ntp:/sbin/nologin
    36:apache:x:48:48:Apache:/var/www:/sbin/nologin
    37:saslauth:x:498:76:"Saslauthd user":/var/empty/saslauth:/sbin/nologin
    38:postfix:x:89:89::/var/spool/postfix:/sbin/nologin
    39:pulse:x:497:496:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
    40:sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
    41:tcpdump:x:72:72::/:/sbin/nologin
    42:xm:x:500:500:xh:/home/xm:/bin/bash
    43:mysql:x:496:493::/home/mysql:/sbin/nologin
    44:nginx:x:495:492::/home/nginx:/sbin/nologin

#### 正则表达式第二波字符说明 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 6]

#### 正则表达式第三波字符说明 ####

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 7][]

\[nrt\] 有n 有r 有t 符合要求  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 8]  
\[^nrt\] 非n 非r 非t  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 9]

字数重复次数的正则表达式使用  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 10]  
**注意：**  
![在这里插入图片描述][20190805223545192.png]  
![在这里插入图片描述][20190807195910196.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70]: /images/20220123/2a463a5eaba249f7ac6ef6a766693449.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 1]: /images/20220123/8cf22ace83204760b5439d2dbb1cd3c7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 2]: /images/20220123/5a6a29e4ef214d51bab36aa583d0a27c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 3]: /images/20220123/154686fd7c0d44008ef877178221156c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 4]: /images/20220123/cd5a62f04146468da8640dc3acd2c2e2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 5]: /images/20220123/03f6c779912242d6ace0d549c826bfed.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 6]: /images/20220123/1d95a58bbfbb40928dde0f2428c98f6e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 7]: /images/20220123/a8c3e222a59545a5b2560931f7a3bd17.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 8]: /images/20220123/662a31e2b448499788d4d7cbbcf1189b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 9]: /images/20220123/0eb0c4c95aee4d2b99d33928f8b1338c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MzQ4OQ_size_16_color_FFFFFF_t_70 10]: /images/20220123/d9e2fcf0ea1148eba907abc7084c04f8.png
[20190805223545192.png]: /images/20220123/2b4e8b40e74142bd966a1f9c75154353.png
[20190807195910196.png]: /images/20220123/b9ef72d83c404459a61d2432a04443f5.png