一、查单个字符匹配$4=0的行
[root@k8s-node01 ~]# awk -F: '$4=="0" {print $0}' /etc/passwd
root:x:0:0:root:/root:/bin/bash
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
operator:x:11:0:operator:/root:/sbin/nologin
二、查包含数字0的行
[root@k8s-node01 ~]# cat /etc/passwd | awk -F ":" '{print $0}' | grep -i "0"
root:x:0:0:root:/root:/bin/bash
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
operator:x:11:0:operator:/root:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
smcftp:x:1000:1000::/home/smcftp:/sbin/nologin
virtusers:x:1001:1001::/home/virtusers:/sbin/nologin
vsftpd:x:1002:1002::/home/vsftpd:/sbin/nologin
ftptest:x:1003:1003::/home/ftptest:/sbin/nologin
zabbix:x:993:990::/home/zabbix:/bin/bash
prometheus:x:1004:1004::/home/prometheus:/sbin/nologin
smc:x:1005:1006::/home/smc:/bin/bash
puppet:x:52:1006:Puppet:/var/lib/puppet:/sbin/nologin
jenkins:x:1006:1008::/home/jenkins:/bin/bash
三、
https://ask.csdn.net/questions/710284
比如文本a.txt有两行如下：
a
bnabn
现在我要匹配只含有“a”的那一行，如何写。
awk '/^a$/ {print}' a.txt
