引言

#!/bin/sh
#*************************************************************
# 网络测试脚本
# written by braincol 2011.04.06
#*************************************************************

#****************************************
#被注释掉的方法获取网关所需的时间太长！
#GATEWAY=`route | grep 'default.*' | awk '1{split($0,parts," ");print parts[2]}'` 
#**************************************** 
GATEWAY=`cat /proc/net/route | awk '
	function char2num(char) 
	{
 		dec = "0123456789";   # decimal
 		cap = "ABCDEF";       # capital
 		min = "abcdef";       # minuscule
 		if( length(char) > 1 ){
  			print "the length of the input char is erro!";
  			return;
 		}
 		if( index(dec,char) > 0 ) {
  			return (index(dec,char) - 1);
 		} 
 		else if( index(cap,char) > 0 ) {
	 		return (index(cap,char) + 9);
	 	}
	 	else if( index(min,char) > 0 ) {
	  		return (index(min,char) + 9);
	 	}
		else{
	 		#print "input char error!"
			return 0
		}
	} 

	function str2ip(str) {
 		split(str,out,"");
 		strout= sprintf("%d.%d.%d.%d",	
  					char2num(out[7])*16 + char2num(out[8]),
					char2num(out[5])*16 + char2num(out[6]),
 					char2num(out[3])*16 + char2num(out[4]),
					char2num(out[1])*16 + char2num(out[2]));
 		return strout;
	}
	
	(FNR>1) {
		split($0,parts," ")
		if(parts[3] != "00000000"){
			print str2ip(parts[3])
		}
	}'`

#*******************************************
#被注释掉的方法获取的dns太多，实际只需一个就够了
#NAMESERVER=`cat /etc/resolv.conf | grep 'nameserver.*' | sed 's/^.*nameserver *//g'`
#******************************************* 
NAMESERVER=`cat /etc/resolv.conf |awk '(FNR<2) && /nameserver.*/' |sed 's/^.*nameserver *//g'`

INTERNET="www.baidu.com"
echo "GATEWAY: " $GATEWAY
echo "NAMESERVER: " $NAMESERVER
echo "INTERNET: " $INTERNET
echo "------------------------------"

ping -c 3 127.0.0.1 > /dev/null 2>&1
if [ "$?" != "0" ]; then
	echo "Network card does not work! "
else
	echo "Network card is OK!"
fi
 
ping -c 3 $GATEWAY > /dev/null 2>&1
if [ "$?" != "0" ]; then
	echo "Can't connect to GateWay!"
else
	echo "GateWay is connected!"
fi

ping -c 3 $NAMESERVER > /dev/null 2>&1
if [ "$?" != "0" ]; then
	echo "Can't connect to DNS!"
else
	echo "DNS is connected!"
fi

ping -c 3 $INTERNET > /dev/null 2>&1
if [ "$?" != "0" ]; then
	echo "Can't connect to Internet!"
else
	echo "Internet is connected!"
fi
exit 0