Shell special Characters

Special symbols

• Wildcard characters, any character
  ？ Any of the characters
  . #注释字符
  \ de-Semantic characters
  | Pipeline

Several commands related to pipelines
Cut select information for the row analysis
Main parameters
-B: Split in bytes. These byte locations will ignore multibyte character boundaries unless the-n flag is also specified.
-C: Split in characters.
-D: Custom delimiter, default is tab.
-F: Used with-D to specify which area to display.
-N: Cancels splitting multibyte characters. Used only with the-B flag. If the last byte of the character falls within the range of <br/> indicated by the List parameter of the-B flag, the character will be written out; otherwise, the character will be excluded.

Sort sorted by default in ASC code

[[email protected] ~]# sort/etc/passwd
Adm:x:3:4:adm:/var/adm:/sbin/nologin
Avahi-autoipd:x : 170:170:avahi ipv4ll stack:/var/lib/avahi-autoipd:/sbin/nologin
Avahi:x:70:70:avahi MDNS/DNS-SD Stack:/var/run /avahi-daemon:/sbin/nologin
Bin:x:1:1:bin:/bin:/sbin/nologin
Daemon:x:2:2:daemon:/sbin:/sbin/nologin
Dbus:x:81:81:system message bus:/:/sbin/nologin
ftp:x:14:50:ftp user:/var/ftp:/sbin/nologin
games:x:12:100: Games:/usr/games:/sbin/nologin
Halt:x:7:0:halt:/sbin:/sbin/halt
Lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
Mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
Nobody:x:99:99:nobody:/:/sbin/nologin
operator:x:11:0 : Operator:/root:/sbin/nologin
Polkitd:x:999:998:user for Polkitd:/:/sbin/nologin
postfix:x:89:89::/var/ Spool/postfix:/sbin/nologin
Root:x:0:0:root:/root:/bin/bash
Shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
sshd:x:74:74:privilege-separated ssh:/var/empty/sshd:/sbin/nologin
Sync:x:5:0:sync:/sbin:/bin/sync

SORT-R Reverse

WC statistics

-l statistic number of rows-m statistic characters-W statistics
[Email protected] ~]# wc-l 1.txt
1.txt
[Email protected] ~]# wc-m 1.txt
468 1.txt
[Email protected] ~]# wc-w 1.txt
1.txt

Uniq sort-C to go heavy
[Email protected] ~]# sort 2.txt
1
1
1
123
123
2
2
2
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
21st
3
Abc
ABC 1111,222
[Email protected] ~]# Sort 2.txt | Uniq
1
123
2
21st
3
Abc
ABC 1111,222

[Email protected] ~]# Sort 2.txt | Uniq-c
3 1
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222

Tee and > output redirection are similar

[Email protected] ~]# >a.txt #清空a. txt content
[email protected] ~]# cat a.txt #查看
[Email protected] ~]# Sort 2.txt | uniq-c | Tee A.txt #重定向并显示
3 1
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222
[email protected] ~]# cat A.txt
3 1
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222

[Email protected] ~]# Sort 2.txt | uniq-c | Tee-a a.txt #追加
3 1
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222
[email protected] ~]# cat a.txt #查看内容
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222
3 1
2 123
3 2
21 21
1 3
1 ABC
1 ABC 1111,222

TR Replacement Character

[Email protected] ~]# echo "Aminglinux" |tr ' [al] ' [Al] '
Aminglinux
[[email protected] ~]# echo "Aminglinux" |tr ' a ' a '
Aminglinux

Split cut

[Email protected] test]# split-b 100k a.txt
[[email protected] test]# ls
A.txt Xaa Xab
[Email protected] test]# Du-sh
128K A.txt
100K XAA
28K Xab
[Email protected] test]# split-b 100k a.txt ABC. #指定大小
[[email protected] test]# ls
Abc.aa Abc.ab A.txt
[Email protected] test]# split-l a.txt #指定行
[Email protected] test]# ls-l
Total Dosage 260
-rw-r--r--. 1 root root 129633 January 07:31 a.txt
-rw-r--r--. 1 root root 41537 January 07:32 Xaa
-rw-r--r--. 1 root root 35466 January 07:32 xab
-rw-r--r--. 1 root root 36841 January 07:32 xac
-rw-r--r--. 1 root root 15789 January 07:32 xad
[Email protected] test]# wc-l
3549 A.txt
Xaa
Xab
Xac
549 Xad
7098 Total Dosage

Special symbols

$ variable Prefix
！ $ combination, regular inside means end of line
Multiple lines of command write to one line, use; split
~ User home directory, regular expression indicates match
& After the command is placed, the command hangs in the background

>> 2> 2>> &>
[] One of the specified characters, [0-9][a-z][a-z]

|| and && for the logical relationship between commands

[[email protected] ~]# ls 1.txt; wc-l 2.txt
1.txt
2.txt
[[email protected] ~]# ls 1.txt | | Wc-l 2.txt
1.txt
The current polygon command succeeds and does not execute subsequent commands
[[email protected] ~]# ls 1.txt && wc-l 2.txt
1.txt
2.txt
[[email protected] ~]# ls 1a.txt && wc-l 2.txt
LS: Unable to access 1a.txt: No file or directory
When the preceding command is unsuccessful, the following command is not executed

[[Email protected] ~]# [-D aminglinux] | | mkdir Aminglinux
If the Aminglinux directory does not exist, create the Aminglinux directory
[-D n] Fixed format
[[email protected] ~]# ls
1.txt 2.txt 3.txt aaaa.txt aminglinux anaconda-ks.cfg a.txt; : Q Test

[[Email protected] ~]# [-D aminglinux] && mkdir aminglinux
mkdir: Unable to create directory "Aminglinux": File already exists
[[Email protected] ~]# [-D aminglinux] | | mkdir Aminglinux

Shell special Characters