Shulou(Shulou.com)06/02 Report--

In this issue, the editor will bring you about the use of awk in linux. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

Awk introduction

Awk is a line processor. Compared with the advantages of screen processing, there is no memory overflow or slow processing when dealing with large files. It is usually used to format text information.

Awk processing: each row is processed in turn and then output.

Awk command form:

Awk [- F |-f |-v] 'BEGIN {} / / {command1; command2} END {}' file

Parameter description:

-F specifies the delimiter

-f call script

-v defines a variable

'' reference code block

BEGIN initialization code block, initializing the code before processing each line, mainly referencing global variables and setting the FS delimiter

/ / match the code block, which can be a string or a regular expression

{} command code block containing one or more commands

END ending code block, a code block that executes after each line is processed, mainly for final calculation or output ending summary information

Let's take a look at several apps:

Awk-F:'{print NF}'/ etc/passwd / / how many fields are there in each line of the output file? awk-F:'{print $1rec. 2 print NR,$1,$2,$3. 3 print NR,$1,$2,$3 5}'/ etc/passwd / / output the first five fields, OFS='\ t / etc/passwd / / output the first five fields and use tabs to separate the first five fields. 5} 'OFS='\ t' / etc/passwd / / Tab separates the first five fields of the output And print the line number above is the use of awk in linux shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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