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This article mainly shows you "how to use awk in linux". The content is simple and clear. I hope it can help you solve your doubts. Let the editor lead you to study and learn this article "how to use awk in linux".

Awk built-in variables

ARGC command line parameters ARGV command line parameters arrangement ENVIRON support queue system environment variables using FILENAME awk browsed filename FNR browse file number of records FS setting input domain delimiter Equivalent to the command line-F option NF the number of fields of browsing records NR the number of records read OFS output domain delimiter ORS output record separator RS control record separator $0 variable refers to the entire record. $1 represents the first field of the current row, and $2 represents the second field of the current row. and so on. $NF is number finally, which represents the information in the last column, which is different from the variable NF, which counts the total number of each row and column.

Display of commonly used commands

Awk is good at column output

Search / etc/passwd all lines with the root keyword

Awk'/ root/' / etc/passwd

[this is the use of pattern, and only lines that match pattern (in this case root) will execute action (no action specified, default output of each line)]

Search for all lines with the root keyword in / etc/passwd and display the corresponding shell

Awk-F:'/ root/ {print $7}'/ etc/passwd

Statistics / etc/passwd: file name, line number of each line, number of columns per line, corresponding full line content:

Awk-F':'{print "filename:" FILENAME ", linenumber:" NR ", columns:" NF ", linecontent:" $0}'/ etc/passwd

Using printf instead of print can make the code more concise and easy to read

Awk-F:'{printf ("filename:s, linenumber:%3s,column:%3s,content:%3f\ n", FILENAME,NR,NF,$0)}'/ etc/passwd

Print the second line of information for / etc/passwd/

Awk-F: 'NR==2 {print "filename:" FILENAME, $0}' / etc/passwd

Filtering usage of awk

Ls-lF | awk'/ ^ dplink'

Specify a specific delimiter to query the first column

Awk-F ":" {print $1}'/ etc/passwd is all the content of this article "how to use awk in linux". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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