Bash awk 基本入门

Bash awk 基本入门

Awk ‘patten {action}’ file

Akw command is used to handle fields in one line.

Analize every line in the file, and if the line match the patten, then do the action.

pattern field is optional.

$0 indicates the whole line.

The first field is $1.

[braveyly@m-net ~]$ cat awk.txt liwei  27  male     hust lijing 24  femaile  cnnu hujuan 22  female   cnnu hurui  18  male     hust [braveyly@m-net ~]$ awk '$2 > 23 {print $1, $3, $4}' ./awk.txt liwei male hust lijing femaile cnnu [braveyly@m-net ~]$ awk '$4 == "hust" {print $0}' ./awk.txt liwei  27  male     hust hurui  18  male     hust [braveyly@m-net ~]$ awk '$4 ="hust" {print $0}' ./awk.txt liwei 27 male hust lijing 24 femaile hust hujuan 22 female hust hurui 18 male hust

awk -Fchar '{action}'

Seperate the line into different fileds by single char.

No blank is between -F and char.

[nick@d01 bash]$ cat sort4.txt daemon:x:2:2:daemon:/sbin:/sbin/nologin root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin   [nick@d01 bash]$ awk -F: '{print $7}' ./sort4.txt /sbin/nologin /bin/bash /sbin/nologin

 

-F argument indicates the separator of fields.