shell字符截取命令之awk命令

一 语法

 

 

二 实战

[root@localhost ~]# cut -f 2,4 student.txt

furong 85

fengj 60

cang 70

[root@localhost ~]# awk '{printf $2 "\t" $4 "\n"}' student.txt

furong 85

fengj 60

cang 70

[root@localhost ~]# awk '{print $2 "\t" $4}' student.txt

furong 85

fengj 60

cang 70

[root@localhost ~]# df -h|awk '{print $1 "\t" $3}'

Filesystem Used

/dev/sda3 124M

devtmpfs 0

tmpfs 84K

tmpfs 7.0M

tmpfs 0

/dev/sda5 3.9G

/dev/sda7 33M

/dev/sda2 1.3G

/dev/sda1 153M

tmpfs 16K

tmpfs 0

 

三 在awk命令的输出中支持print和printf命令

 

 

四 实战

[root@localhost ~]# df -h|grep "/dev/sda5" |awk '{print $5}'

39%

[root@localhost ~]# df -h|grep "/dev/sda5" |awk '{print $5}'|cut -d "%" -f 1

39

[root@localhost ~]# awk 'BEGIN{printf "This is a transcript \n"}{printf $2 "\t" $4 "\n"}' student.txt

This is a transcript

furong 85

fengj 60

cang 70

[root@localhost ~]# awk 'END{printf "This is a transcript \n"}{printf $2 "\t" $4 "\n"}' student.txt

furong 85

fengj 60

cang 70

This is a transcript

[root@localhost ~]# cat /etc/passwd | grep "/bin/bash"

root:x:0:0:root:/root:/bin/bash

cakin24:x:1000:1000:cakin24,cakin,cakin,cakin:/home/cakin24:/bin/bash

test:x:1003:1001::/home/xxx:/bin/bash

cls:x:1001:1001:dgdzmx:/home/cls:/bin/bash

[root@localhost ~]# cat /etc/passwd | grep "/bin/bash"|\

> awk 'BEGIN{FS=":"}{printf $1 "\t" $3 "\n"}'

root 0

cakin24 1000

test 1003

cls 1001

[root@localhost ~]# cat student.txt |awk '$4>=70{printf $2 "\n"}'

furong

cang