如果检测系统是否已经连接到 internet

flyinflash

我的想法是这样的，把 ping 的结果输出到的 /tmp/xx$$，然后抓 /tmp/xx$$ 中的字符串分析……
我把网线拨了，然后等啊等啊，等啊等啊……竟然卡在`ping google.com`一直没有反应……

请问弟兄们一般是怎么检测的？

2. # paths to programs
3. ECHO=/bin/echo
4. IFCONFIG=/sbin/ifconfig
5. PING=/bin/ping
7. # defaults
8. ME=`basename $0`
10. # make sure run by root
11. if [ "`/usr/bin/id -u`" != 0 ] ; then
12.     $ECHO "$ME: You must be root to run this script" >& 2
13.     exit 1
14. fi
16. # test connecting network
17. if [ -f $PING ] ; then
18.     $ECHO "test connecting network..."
19.     TMP_FILE=/tmp/$ME-$$
20.     $PING -c 3 google.com > $TMP_FILE
21. fi

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wd_afei

或许有一个对你有用，有问题先看看 man

2.        -w deadline
3.               Specify a timeout, in seconds, before ping exits regardless of how many packets  have
4.               been  sent  or received. In this case ping does not stop after count packet are sent,
5.               it waits either for deadline expire or until count probes are answered  or  for  some
6.               error notification from network.
8.        -W timeout
9.               Time  to  wait for a response, in seconds. The option affects only timeout in absense
10.               of any responses, otherwise ping waits for two RTTs.

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kpld

if !( ping -c 3  -W 2 google.com  )
then
    echo "Couldn't ping."
else
    echo "ing successful!";
fi

flyinflash

非常谢谢两位！