awk 企业案例集

/etc/services 文件的内容的格式如下：

ftp-data 20/tcp
ftp-data 20/udp
# 21 is registered to ftp, but also used by fsp
ftp 21/tcp
ftp 21/udp fsp fspd
ssh 22/tcp # The Secure Shell (SSH) Protocol
ssh 22/udp # The Secure Shell (SSH) Protocol
telnet 23/tcp
telnet 23/udp

 

企业案例1：取出常用服务端口号（ftp,http,https,mysql,ssh）

[root@linux-node1 files]# awk -F "[ /]+" '$1~/^(ftp|http|https|mysql|ssh|ftp-data)$/ {print $1,$2}' /etc/services |sort -nk2|uniq
ftp-data 20
ftp 21
ssh 22
http 80
https 443
mysql 3306

 

 

企业案例2：取出常用服务端名称（80,443,3306,23,22,25,21）

[root@linux-node1 files]#  awk -F "[ /]+" '$2~/^(80|443|3306|23|22|25|21)$/ {print $1,$2}' /etc/services |sort -nk2|uniq|grep -v "#"
ftp 21
ssh 22
telnet 23
smtp 25
http 80
https 443
mysql 3306

 

awk取行

[root@linux-node1 files]# awk 'NR>=2&&NR<=5 {print NR,$0}' /etc/passwd
[root@linux-node1 files]# awk 'NR==2,NR==5 {print NR,$0}' /etc/passwd
2 bin:x:1:1:bin:/bin:/sbin/nologin
3 daemon:x:2:2:daemon:/sbin:/sbin/nologin
4 adm:x:3:4:adm:/var/adm:/sbin/nologin
5 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

sed -n '2,5p' /etc/passwd　　# 取行建议用sed命令