范例一
打印指定列中匹配80开头并以80结束的行
关系符号注释
~ 关系操作符
~ 匹配正则
!~ 不匹配正则
[root@linux ~]# cat a.txt
afjdkj 80
lkdjfkja 8080
dfjj 80
jdsalfj 808080
jasj 80
jg 80
linux 80
80 ajfkj
asf 80
80 linux
[root@xingfujie ~]# awk '{if($2~/^80$/)print}' a.txt
afjdkj 80
dfjj 80
jasj 80
jg 80
linux 80
asf 80
范例二
范例 2.1
grep -v ffff过滤ipv6的地址，显示:80的行，删除A到Z和_对应的行，判断已:作为分隔符，打印第三列等于80的行。
[root@linux ~]# netstat -nat | grep -v ffff | grep ":80" | tr -d "[A-Z][_]"| awk -F : '{if($3==80)print}'
tcp 0 0 10.15.201.29:38393 123.125.106.196:80
tcp 0 0 10.15.201.29:38383 60.28.236.116:80
tcp 0 0 10.15.201.29:44949 60.28.236.112:80
tcp 0 0 10.15.201.29:41445 60.28.236.116:80
tcp 0 0 10.15.201.29:47630 60.28.236.112:80
tcp 0 0 10.15.201.29:48624 60.28.236.116:80
tcp 0 0 10.15.201.29:48129 60.28.236.116:80
tcp 0 0 10.15.201.29:48837 60.28.236.112:80
tcp 0 0 10.15.201.29:50506 60.28.236.112:80
tcp 0 0 10.15.201.29:53923 60.28.236.112:80
范例 2.2
不加grep ":80"一样可以查出正确结果
[root@linux ~]# netstat -nat | grep -v ffff | tr -d "[A-Z][_]"| awk -F : '{if($3==80)print}'
tcp 0 0 10.15.201.29:60047 118.67.112.70:80
tcp 0 0 10.15.201.29:49038 123.125.106.196:80
tcp 0 0 10.15.201.29:37035 123.125.106.196:80
tcp 0 0 10.15.201.29:35936 118.67.112.70:80
tcp 0 0 10.15.201.29:35972 60.28.236.112:80
tcp 0 0 10.15.201.29:35056 60.28.236.116:80
tcp 0 0 10.15.201.29:48777 60.28.236.112:80
tcp 0 0 10.15.201.29:47173 60.28.236.116:80
tcp 0 0 10.15.201.29:53014 60.28.236.116:80
tcp 0 0 10.15.201.29:51816 60.28.236.112:80
tcp 0 0 10.15.201.29:53109 60.28.236.112:80
tcp 0 0 10.15.201.29:52274 60.28.236.112:80
tcp 0 0 10.15.201.29:49854 60.28.236.116:80
tcp 0 0 10.15.201.29:50339 60.28.236.112:80
tcp 0 0 10.15.201.29:60595 60.28.236.116:80