linux - 解析大括号中的 block

Question

我正在尝试解析如下所示的 dhcpd.conf 文件:

authoritative;

subnet x.x.x.x netmask x.x.x.x {
    range x.x.x.x x.x.x.x;
    deny unknown-clients;
    default-lease-time 86400;
    max-lease-time 86400;
    option domain-name "bla";
    option domain-name-servers x.x.x.x;
    option broadcast-address x.x.x.x;
    option subnet-mask x.x.x.x;
    option routers x.x.x.x;

    host host1 {
            hardware ethernet 00:e1:4c:68:00:53;
            fixed-address 1.1.1.1;
    }

    host host2 {
            hardware ethernet 01:e2:4d:69:01:54;
            fixed-address 2.2.2.2;
    }

    host host3 {
            hardware ethernet 02:e3:4e:70:02:55;
            fixed-address 3.3.3.3;
    }

    host host4 {
            hardware ethernet 03:e4:4f:71:03:56;
            fixed-address 4.4.4.4;
    }

    host host5 {
            hardware ethernet 04:e5:5f:72:04:57;
            fixed-address 5.5.5.5;
    }
}

最后，我需要遍历主机 block (无论它们的名称如何)并将 MAC 地址和 IP 地址分配给变量以处理组合。到目前为止，我设法只使用一个变量来做到这一点:

for MAC in `cat /etc/dhcp/dhcpd.conf | grep "hardware ethernet" | awk '{ print $3 }' | tr ";" " "`
do
    echo "Found MAC address: " $MAC "Found IP: <I need the IP Variable here...>" 
done

也许以某种方式“grep”主机 block 以便循环遍历这些 block 会更好，但我不知道该怎么做。

谁能给我一个提示，告诉我如何做到这一点？

谢谢

Answer 1

鉴于输入文件的格式完全相同(MAC 后跟 IP)，sed 后的一行将给出“MAC、IP”csv 对列表。你可以解析它并做任何你想做的事。

sed -n '/\s*hardware ethernet/{s/\s*hardware ethernet \(.*\);/\1/;N;s/\([a-z0-9:]*\)\s*fixed-address \(.*\);/\1,\2/p}' /etc/dhcp/dhcpd.conf

输出:

00:e1:4c:68:00:53,1.1.1.1
01:e2:4d:69:01:54,2.2.2.2
02:e3:4e:70:02:55,3.3.3.3
03:e4:4f:71:03:56,4.4.4.4
04:e5:5f:72:04:57,5.5.5.5

要生成与示例中一样的准确输出，

sed -n '/\s*hardware ethernet/{s/\s*hardware ethernet \(.*\);/\1/;N;s/\([a-z0-9:]*\)\s*fixed-address \(.*\);/Found MAC address: \1, Found IP: \2/p}' /etc/dhcp/dhcpd.conf

输出:

Found MAC address: 00:e1:4c:68:00:53, Found IP: 1.1.1.1
Found MAC address: 01:e2:4d:69:01:54, Found IP: 2.2.2.2
Found MAC address: 02:e3:4e:70:02:55, Found IP: 3.3.3.3
Found MAC address: 03:e4:4f:71:03:56, Found IP: 4.4.4.4
Found MAC address: 04:e5:5f:72:04:57, Found IP: 5.5.5.5

---

编辑

您可以从每一对中提取 MAC 和 IP，并按如下方式使用它们。

for v in $(sed -n '/\s*hardware ethernet/{s/\s*hardware ethernet \(.*\);/\1/;N;s/\([a-z0-9:]*\)\s*fixed-address \(.*\);/\1,\2/p}' /etc/dhcp/dhcpd.conf); do
    mac="${v%,*}"
    ip="${v#*,}"
    echo "MAC: $mac"
    echo "IP: $ip"
done