The LSORT,UNIQ,CUT,WC,SEQ command in the shell uses

Sort

The sort command sorts the rows in the files specified by the file parameter and writes the results to standard output. If the file parameter specifies multiple files, the sort command connects the files and sorts them as a file.

Sort syntax

[[email protected] ~]# sort [-fbmnrtuk] [file or stdin]

Options and Parameters:

-F: Ignores case differences, such as a and a are treated as encodings;

-B: Ignores the first whitespace part;

-M: Sort by month name, such as JAN, DEC and so on;

-N: Sort using "pure number" (by default it is sorted by text type);

-R: Reverse sort;

-U: Is Uniq, in the same data, only one row is represented;

-T: delimiter, the default is to use the [tab] key to separate;

K: The meaning of sorting by that interval (field)

Sort the accounts of the/etc/passwd

[Email protected] ~]# CAT/ETC/PASSWD | Sort

Adm:x:3:4:adm:/var/adm:/sbin/nologin

A

Apache:x:48:48:apache:/var/www:/sbin/nologin

B

Bin:x:1:1:bin:/bin:/sbin/nologin

D

Daemon:x:2:2:daemon:/sbin:/sbin/nologin

Sort is sorted by default with the first data, and by default it is sorted by string, so the letter a begins in ascending order.

/ETC/PASSWD content is separated by:, I want to sort by the third column, How to

[Email protected] ~]# CAT/ETC/PASSWD | Sort-t ': '-K 3

R

Root:x:0:0:root:/root:/bin/bash

U

Uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin

O

Operator:x:11:0:operator:/root:/sbin/nologin

B

Bin:x:1:1:bin:/bin:/sbin/nologin

G

Games:x:12:100:games:/usr/games:/sbin/nologin

The default is to sort by string, if you want to use numbers to sort:

cat/etc/passwd | Sort-t ': '-K 3n

R

Root:x:0:0:root:/root:/bin/bash

D

Daemon:x:1:1:daemon:/usr/sbin:/bin/sh

B

Bin:x:2:2:bin:/bin:/bin/sh

The default is ascending sort, if you want to sort in reverse order, as follows

cat/etc/passwd | Sort-t ': '-K 3NR

N

Nobody:x:65534:65534:nobody:/nonexistent:/bin/sh

N

Ntp:x:106:113::/home/ntp:/bin/false

M

Messagebus:x:105:109::/var/run/dbus:/bin/false

S

Sshd:x:104:65534::/var/run/sshd:/usr/sbin/nologin

If you want to/etc/passwd, first sort by the 2nd character of the sixth field to the 4th character, and then reverse-sort based on the first field.

cat/etc/passwd | Sort-t ': '-K 6.2,6.4-k 1r

Sync:x:4:65534:sync:/bin:/bin/sync

P

Proxy:x:13:13:proxy:/bin:/bin/sh

B

Bin:x:2:2:bin:/bin:/bin/sh

S

Sys:x:3:3:sys:/dev:/bin/sh

See how many shells the/etc/passwd has: sort the seventh field of/etc/passwd and then go back to the heavy one:

cat/etc/passwd | Sort-t ': '-K 7-u

R

Root:x:0:0:root:/root:/bin/bash

S

Syslog:x:101:102::/home/syslog:/bin/false

D

Daemon:x:1:1:daemon:/usr/sbin:/bin/sh

Sync:x:4:65534:sync:/bin:/bin/sync

S

Sshd:x:104:65534::/var/run/sshd:/usr/sbin/nologin

Uniq

The Uniq command removes duplicate rows from a sorted file, so Uniq is often used in combination with sort. That is, in order for the Uniq to work, all duplicate rows must be contiguous.

Uniq syntax

[Email protected] ~]# Uniq [-ICU]

Options and Parameters:

-I: Ignoring the difference between uppercase and lowercase characters;

-C: Counting

-U: only display unique rows

The contents of Testfile are as follows

Cat Testfile

H

Hello

W

World

F

Friend

H

Hello

W

World

H

Hello

Deleting an unordered file directly will reveal that no rows have been deleted

#uniq testfile

H

Hello

W

World

F

Friend

H

Hello

W

World

H

Hello

Sort files, the default is to go to heavy

#cat Words | Sort |uniq

Friend

H

Hello

W

World

Duplicate rows are deleted after sorting, and the number of occurrences of the row is output at the beginning of the line

#sort Testfile | Uniq-c

1 friend

3 Hello

2 World

Displays only duplicate rows, and displays the number of repetitions of the row at the beginning of the line

#sort Testfile | Uniq-dc

3 Hello

2 World

Show only rows that are not duplicates

Sort Testfile | Uniq-u

F

Friend

Cut

The Cut command extracts text columns from a text file or text stream.

Cut grammar

[[email protected] ~]# cut-d ' delimited characters '-f fields <== used to have a specific delimiter character

[

[[email protected] ~]# cut-c character range <== used to arrange neat information

Options and Parameters:

-D: followed by delimited characters. Used with-F;

-F: Divides a piece of information into several paragraphs according to the delimiter character of-D, and uses-F to remove the meaning of the paragraph;

-C: Remove the fixed character range in units of character (characters);

The PATH variable is as follows

[Email protected] ~]# echo $PATH

/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/x11r6/bin:/usr/games

#

# 1 | 2 | 3 | 4 | 5 | 6 | 7

To take the path variable out, I'm going to find a fifth path.

#echo $PATH | Cut-d ': '-F 5

/usr/local/bin

Take the path variable out and I'll find the third and fifth paths.

#echo $PATH | Cut-d ': '-f 3,5

/

/sbin:/usr/local/bin

Take the path variable out and I'll find the third to last path.

echo $PATH | Cut-d ': '-f 3-/sbin:/usr/sbin:/usr/local/bin:/usr/x11r6/bin:/usr/games

Take the path variable out and I'll find the first to third path.

#echo $PATH | Cut-d ': '-f 1-3

/bin:/usr/bin:/sbin:

Take the path variable out, I want to find the first to third, there is a fifth path.

echo $PATH | Cut-d ': '-f 1-3,5

/bin:/usr/bin:/sbin:/usr/local/bin

Practical Example: Display only/etc/passwd users and shells

#cat/etc/passwd | Cut-d ': '-f 1,7

R

Root:/bin/bash

D

Daemon:/bin/sh

B

Bin:/bin/sh

Wc

The number of words in the statistics file, how many lines, how many characters.

WC syntax

[Email protected] ~]# WC [-LWM]

Options and Parameters:

-L: Only the travel is listed;

-W: Lists only the number of words (English word);

-M: how many characters;

Use WC statistic/etc/passwd by default

#wc/etc/passwd

1719/etc/passwd

40 is the number of rows, 45 is the number of words, and 1719 is the number of bytes

The WC commands are relatively simple to use and each parameter is used as follows:

#wc-L/etc/passwd #统计行数, which is commonly used when recording numbers

40/ETC/PASSWD #表示系统有40个账户

#

#wc-W/etc/passwd #统计单词出现次数

45/etc/passwd

#

#wc-M/etc/passwd #统计文件的字节数

1719

Seq

It has three options

-F,--format=format use printf style floating-point format (default:%G)

-S,--separator=string use STRING to separate numbers (default: \ n)

-W,--equal-width equalize width by padding with leading zeroes

-F is most commonly used, such as making 10 names dir001, dir002. DIR010 's catalogue, we can

Run the following command to

Seq-f ' dir%03g ' 1 10 | Xargs mkdir

Or

mkdir $ (seq-f ' dir%03g ' 1 10)

It is in printf format,%03g ' stands for three-bit floating-point numbers, in this way, such as with BASH3 printf

Also available as an equivalent command

printf ' dir%03d\n ' {1..10} | Xargs mkdir or mkdir ' printf ' dir%03d ' {1..10} '

Awk can of course also

awk ' BEGIN {while (num <) printf "dir%03d\n", ++num; exit} ' | Xargs mkdir

It would be quicker than writing a script, not written

For DIR in 001 002 003 004 005 006 007 008 009 010

Do

mkdir dir$

Done

You can also use SEQ to download a number of JPEG, as long as the format has a numerical order, especially in some XXX site;)

For i in ' seq-f '%02g ' 1 20 '

Do

if! Wget-p $HOME/tmp-c; Then

Wget-p $HOME/tmp-c $_

Fi

Done

The-s option mainly changes the output of the separator, the default is \ n, is newline

Case

With-S can be changed, such as

Seq-s ' 1 10

1 2 3 4 5 6 7 8 9 10 with a space as a splitter

Statistics Command processing time:

Time for I in $ (seq 1111);d o count=${#chars};d one;

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The LSORT,UNIQ,CUT,WC,SEQ command in the shell uses