Awk command usage, awk

Awk command usage, awk

Awk Programming Language/Data Processing Engine

Creator: Aho weinberger kernighan

Check input based on pattern matching (read row-by-row output)

Print the expected matching result to the screen

Syntax format:

Awk 'mode {operation}' file 1 file 2 .....

Common built-in Variables

The ordinal number of the row being processed by NR (row number)

FS fields are separated. The default value is space or Tab space.

$ N the nth field of the current row

$0 all text content of the current row

Output text by line number

Awk 'nr = 1, NR = 3 {print} 'file.txt

Awk '(NR = 1) | (NR = 3) {print}' file.txt

Use comparison operations

Awk '(NR % 2 = 1) {print}' file.txt outputs all odd rows

Awk '(NR % 2 = 0) {print}' file.txt outputs all even rows

Use Regular Expressions

Awk '/2/{print}' file.txt

Awk '/base $/{print}' file.txt

Specify the separator and specify the output Fields

Awk 'nr = 2, NR = 3 {print $1, $3} 'file.txt outputs the 1, 3 Field of Row 2-3

Awk-F. '$5 = "yes" {print $0}' file.txt output the fifth field separated by. Contains the rows of yes