Shell special symbol Cut Command sort_wc_uniq command tee_tr_split command shell special symbol

• Shell Special Symbol Cut command

Special symbols

* wildcard characters, any of any character

？ Any one character

# comment Characters

\ de-Semantic characters

C=\ $a \ $b

Echo $c

| Pipe character

Cat 1.txt |less

Cat 1.txt |more

Cut intercept string

Show first 2 rows

CAT/ETC/PASSWD |head-2

Cut ":" First paragraph cut-d ":"-F 1

Cut two: cut-d ":"-F

ETC/PASSWD the first two lines, cut 1 to three segments with a colon

CAT/ETC/PASSWD |head-2 |cut-d ":"-F 1-3

[Email protected]:~# cat/etc/passwd |head-2 |cut-d ":"-F

Root:x

Bin:x

[Email protected]:~# cat/etc/passwd |head-2 |cut-d ":"-F 1-2

Root:x

Bin:x

[Email protected]:~# cat/etc/passwd |head-2 |cut-d ":"-F 1-3

root:x:0

Bin:x:1

CUT specifies the number of characters:

Cut-c 4

[Email protected]:~# cat/etc/passwd |head-2 |cut-c 4

T

:

• Sort_wc_uniq command

Sort order-N numerically sort-R reverse order

SORT/ETC/PASSWD alphabetically by first letter

Fetch file content first 10 lines write to 1.txt

HEAD/ETC/PASSWD > 1.txt

Vim 1.txt Editor, write several special symbols * "<>";?

Sort 1.txt

The default is the special symbol in front, then the number, alphabetical order, the * number in the back of the line

Sort-n 1.txt

will be sorted numerically, letters and special symbols will be considered to be 0

SORT-NR 1.txt Reverse order the largest in the front

Sort-t-kn1/-kn2 delimiter Specifies the order of the paragraphs

Wc-l count rows

Wc-m Statistic character Count

[Email protected]:~# wc-l 1.txt

1.txt

[Email protected]:~# wc-m 1.txt

432 1.txt

[Email protected]:~# vim 2.txt

Input

Abc

123

: Wq

[Email protected]:~# wc-m 2.txt

8 2.txt

[Email protected]:~# cat-a 2.txt

abc$

123$

Each row has a newline character $

Wc-w 2.txt counts the number of words, which are distinguished by whitespace characters

[Email protected]:~# wc-w 2.txt

2 2.txt

Uniq (unique) 2.txt to repeat

[Email protected]:~# uniq 3.txt

1

222

333

4

56476

[Email protected]:~# cat 3.txt

1

1

1

222

333

4

4

56476

Sort first, then count.

Number of repetitions of statistics:

Sort 2.txt |uniq-c

[Email protected]:~# sort 3.txt |uniq-c

3 1

1 222

1 333

2 4

1 56476

• Tee_tr_split command

Piping |tee and > Similar, redirects are also displayed on the screen

Role: Redirect and print to the screen

[Email protected]:~# sort 3.txt |uniq-c > A.txt

[Email protected]:~# cat A.txt

3 1

1 222

1 333

2 4

1 56476

[Email protected]:~# sort 3.txt |uniq-c |tee b.txt

3 1

1 222

1 333

2 4

1 56476

[Email protected]:~# cat B.txt

3 1

1 222

1 333

2 4

1 56476

[Email protected]:~#

Both ">" and "|tee" can be written to a file

Empty a.txt

>a.txt

>> additional, |tee-a can also be added

|tee-a Append

[Email protected]:~# sort 3.txt |uniq-c |tee-a b.txt

TR replacement character, tr ' a ' B ', case replacement TR ' [A-z] ' [A-z] '

Change XB to uppercase XB

[Email protected]:~# echo ' xiaobo ' |tr ' [XB] ' [XB] '

Xiaobo

change x to X individually

[Email protected]:~# echo ' Xiaobo ' |tr ' x ' x '

Xiaobo

Change the lowercase letter to uppercase

[Email protected]:~# echo ' xiaobo ' |tr ' [A-z] ' [A-z] '

Xiaobo

Change all the letters to 1.

[Email protected]:~# echo ' xiaobo ' |tr ' [A-z] ' 1 '

111111

Log file 800G words, reading difficulties, can be cut

Append all the Conf files in the ETC to the A.txt file.

[Email protected]:~# find/etc/-type f-name "*conf"-exec Cat {} >> a.txt \;

[Email protected]:~# du-sh a.txt

1.1M A.txt

Cutting files A.txt, 100K per file

[Email protected]:~# du-sh a.txt

464K A.txt

[Email protected]:~# split-b 100k a.txt

[Email protected]:~# ls

A.txt xaa xab xac xad xae

Specify a filename prefix

[Email protected]:~# rm-f x*

[Email protected]:~# split-b 100K a.txt ABC

[Email protected]:~# ls

ABCAA abcab ABCAC Abcad abcae a.txt

Cut one file per 1000 lines

[Email protected]:~# split-l a.txt

[Email protected]:~# ls

A.txt xaa xab xac xad xae xaf xag xah xai xaj xak xal xam

[Email protected]:~# wc-l a.txt

12764 A.txt

• Shell Special Symbols

$ variable prefix,! $ combination, regular inside means end of line

Multiple commands are written to one line, separated by semicolons.

~ User home directory, followed by regular expression to indicate match

& put the command behind the command and throw it backstage.

Write redirect >, Chase redirect >> &> (bad redirect and correct redirect output)

[] One of the specified characters, [0-9],[A-ZA-Z],[ABC]

|| and &&, used between commands

[[email protected] ~]# for i in ' SEQ 1 10 '

> Do

> Echo $i

> Done

Multiple commands separated by semicolons

[[email protected] ~]# for i in ' seq 1 ';d o echo $i; Done

|| Represents or, if the previous command executes successfully, the subsequent command is not executed, and if the preceding command does not succeed, continue with the following command

[[email protected] ~]# ls la.txt| | Wc-l 1.txt

LS: Unable to access la.txt: No file or directory

0 1.txt

[[email protected] ~]# Wc-l 1.txt | | LS La.txt

0 1.txt

&& if the previous command succeeds, the following command is executed, and if the previous command fails, the subsequent command is not executed.

If there is a fake, it will not follow.

[[email protected] ~]# ls la.txt && wc-l 1.txt

LS: Unable to access la.txt: No file or directory

[Email protected] ~]# wc-l 1.txt && ls la.txt

0 1.txt

LS: Unable to access la.txt: No file or directory

Determine if a directory exists

[-D Xiaobo] | | mkdir Xiaobo

If the Xiaobo directory does not exist, the directory is created.

If the directory exists, the directory is not created.

Shell special symbol Cut Command sort_wc_uniq command tee_tr_split command shell special symbol