您如何从挖掘结果中解析 SRV 记录的端口？

Question

我正在像这样解析 dig 的输出以获取 SRV 记录的端口。

export SERVER_DNS_NAME=myserver
echo "SERVER_DNS_NAME: " $SERVER_DNS_NAME
echo "dig: " $(dig +noall +answer $SERVER_DNS_NAME SRV )
echo "port old: " $(dig +noall +answer $SERVER_DNS_NAME SRV | cut -d ' ' -f 6)
SERVER_DIG_RESULT=$(dig +noall +answer $SERVER_DNS_NAME SRV )
echo "SERVER_DIG_RESULT: " $SERVER_DIG_RESULT
SERVER_STRING_ARRAY=($SERVER_DIG_RESULT)
for i in "${SERVER_STRING_ARRAY[@]}"
do
  :
  echo $i
done
SERVER_PORT=${SERVER_STRING_ARRAY[6]}
echo "server port new: " $SERVER_PORT
if [ -z $SERVER_PORT ]; then
  echo "invalid port"
  exit 1
fi
until nc -z $SERVER_DNS_NAME $SERVER_PORT
... do something

我的问题是有时端口在数组项 6，有时在 7。

我的问题是：你如何从挖掘结果可靠地解析端口？

Answer 1

将 +short 选项用于 dig，这将为您提供最简短的输出，然后对其进行简单解析：

% dig +short _xmpp-client._tcp.jabber.org. SRV
31 30 5222 hermes2v6.jabber.org.
30 30 5222 hermes2.jabber.org.

Answer 2

你可能也喜欢这个：

host -t SRV mySRVdomain.local                                           
# mySRVdomain.local has SRV record 1 1 2368 e04dc24b-96c6-4b52-8356-42be0d34e7bb.mySRVdomain.local.


# get it as host:port
host -t SRV mySRVdomain.local | sed -r 's/.+ ([^ ]+) ([^ ]+)\.$/:/g'

# This will print: e04dc24b-96c6-4b52-8356-42be0d34e7bb.mySRVdomain.local:2368
# which is the first real URL with PORT

可能和你需要的不完全一样，但你可以理解

Answer 3

使用 Curl 和 AWK 组成快速命令：

curl http://$(dig +short {HOST} srv | awk '{printf "%s:%s\n",,}')

您如何从挖掘结果中解析 SRV 记录的端口？

How do you parse the SRV record's port from a dig result?

dns

bash

port

dig