让 netcat 监听多个 UDP 数据包

Question

如果我像这样运行一个简单的 UDP 侦听器：

nc -l -u -p 1234

然后我似乎只得到第一个入站 UDP 数据包。例如，如果我运行：

$ echo abc | nc -u localhost 1234
  ["abc" appears in output of server as expected]

$ echo abc | nc -u localhost 1234
read(net): Connection refused

Answer 1

使用零 (0) 超时

“服务器”：

nc -kluvw 0 localhost 9000

“客户”：

echo -e "all"     | nc -vuw 0 localhost 9000
echo -e "the"     | nc -vuw 0 localhost 9000
echo -e "udp"     | nc -vuw 0 localhost 9000
echo -e "packets" | nc -vuw 0 localhost 9000

结果：

Connection from 127.0.0.1 port 9000 [udp/*] accepted
all
Connection from 127.0.0.1 port 9000 [udp/*] accepted
the
Connection from 127.0.0.1 port 9000 [udp/*] accepted
udp
Connection from 127.0.0.1 port 9000 [udp/*] accepted
packets

测试：

uname -a
Linux ubuntu 3.2.0-23-generic-pae #36-Ubuntu SMP Tue Apr 10 22:19:09 UTC 2012 i686 i686 i386 GNU/Linux