Shulou(Shulou.com)06/03 Report--

1. Overview of course knowledge.

1) Overview of the three Musketeers awk command

2) three Musketeers awk command execution principle syntax structure

3) practical practice of the three Musketeers' awk command

Inquire about things

Replacement information

Exclude (reverse)

4) three Musketeers awk command advanced functions [array]

Statistical analysis data information summation operation / accumulation operation (one by one)

2. Review of course knowledge

1) sed command syntax format sed parameter 'conditional directive' file information

Parameters:

-n-cancel output mode

-I-actually edit the contents of the file

-r-identify extended regularity

-e-identify multiple conditional operations

Instruction

P-output mode

D-delete operation

A-additional operation

I-insert operation

S-replace operation

G-Global replacement

R-

C-

Conditional information

$

N

N,m

/ character /

\

3. Overview of the three Musketeers awk command

Awk-pattern scanning and processing language

Pattern scanning (processing each line of information in a file) process language (a scripting language)

Function description:

1) be good at column operations on files

2) be good at statistical analysis of data and information

4. The execution principle of the three Musketeers awk command.

Perform the principle process:

Command syntax structure: awk [parameter] 'mode {action information}' file information mode is the condition

5. Three Musketeers awk command operation exercise

Environmental preparation

The default for several columns is the space interval.

Zhang Dandan 41117397: 250:100:175

Zhang Xiaoyu 390320151: 155:90:201

Meng Feixue 80042789: 250:60:50

Wu Waiwai 70271111: 250:80:75

Liu Bingbing 41117483: 250:100:175

Wang Xiaoai 3515064655: 50:95:135

Zi Gege 1986787350: 250:168:200

Li Youjiu 918391635: 175:75:300

Lao Nanhai 918391635: 250:100:175

1. Display the last name and ID number of Xiaoyu

A) find the corresponding lines according to the conditions

Awk / Xiaoyu/ awk.txt select row

B) output the corresponding column information

Awk'/ Xiaoyu/ {print $1 "" $3} 'awk.txt Zhang 390320151awk' / Xiaoyu/ {print $1 recording 3} 'awk.txt Zhang 390320151

Note: $n~/xxx/ specifies to find someone's donation

A person whose surname is zhang shows the amount of his second donation and his first name

Step 1: find out the corresponding line according to the conditions: awk'$1 hammer Zhangmax 'awk.txtZhang Dandan 41117397: 250:100:175Zhang Xiaoyu 390320151: 155

[root@oldboy69 oldboy 10:43:46] # awk-F ":"'{print $2 test08.txt 3} 'test08.txt | column-t

Linux 69

Linux 66

Python 20

Dba 01

Description: use-F to specify column delimiter

[root@oldboy69 oldboy 10:49:50] # awk-F ": |; | @"'{print $2 column 3} 'test08.txt | column-t

Linux 69

Linux 66

Python 20

Dba 01

[root@oldboy69 oldboy 10:49:52] # awk-F "[:; @]"'{print $2 column 3} 'test08.txt | column-t

Linux 69

Linux 66

Python 20

Dba 01

Description: use-F to specify column delimiters, combined with rules can identify multiple delimiters

[root@oldboy69 oldboy 10:54:13] # awk-F "[: @] +'{print $2 column 3} 'test08.txt | column-t linux 69 linux 66 python 20 dba 01 description: use-F to specify column delimiter. You can use [: @] + to treat multiple consecutive delimiters as a whole

Displays the full name and ID number of all people with ID numbers starting with 41

Step 1: find out the corresponding lines according to the conditions

Awk'$3march / ^ 41Universe 'awk.txt

Step 2: output the corresponding column information # awk'$3million / ^ 41 / {print $1, awk.txtZhang Dandan 41117397Liu Bingbing 41117483 shows all id displays ending with 5 or 0, and displays the person's name and ID number.

Do not end with 0 or 5

Show Xiaoyu donations, each time starting with $, such as $110,220,330.

Awk replacement information method

Gsub (/ replaced information /, "what to replace with", column number of information replaced by $n)

Awk'$2~/Xiaoyu/ {gsub (/: /, "$", $4); print $4} 'awk.txt

$155 $90 $201

6. Advanced usage of the three Musketeers awk command

01. Awk schema concept

Normal pattern: using regular matching / line number matching / character matching

Special mode:

What BEGIN does before processing the file (preparation)

A. Use awk as a computer

B, set the variable

Built-in variables:

NR: indicates the line number

NF: represents field information (column)

FS: represents delimiter field information

What END will do after processing the file (follow-up work)

Output result information

Ps: sometimes when quotation marks need to be used stealthily in the system, the same

''-double single quotation marks are incorrect

"double quotation marks are incorrect.

"'"-use single and double quotation marks

C) output the corresponding column information

Align data

7. Summary of awk course

1) awk command syntax format: awk [parameters] 'mode (2) {actions}'} file information

2) how to use awk:

Parameter:-F

-v

Action information: print gsub operation (cumulative summation)

Good at taking out the information of the column

3) Advanced knowledge of awk:

A) the concept of patterns: special models, general models

B) built-in variable: NR NF FS

Preview: (what will be explained next week)

1. Knowledge of user rights

2. Timed task knowledge

3. Disk management knowledge array partition

Take a day off for a comprehensive exam

Basic knowledge of network

Integrated architecture website deployment

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