check_udp_nc插件：使用方法与check_tcp相同。

nagios自带的check_udp使用起来并不方便，下面的插件check_udp_nc用于代替nagios自带的check_udp.


# 'check_udp_nc' command definition
define command{
        command_name    check_udp_nc
        command_line    $USER1$/check_udp_nc.sh $HOSTADDRESS$ $ARG1$
        }

#!/bin/sh
# $1   ServerIP
# S4   UDP Port
# if succeeded ,$?=0,but $?=1
# view $? ,use "echo $?"
/usr/bin/nc -uz -w1 $1 $2 |grep succeeded >/dev/null
if [ $? -eq 0 ]
   then
      echo "$1 udp-port $2 succeeded"
      exit 0
   else
      echo "$1 udp-port $2 failed"
      exit 2
fi