一个ping，traceroute检测shell脚本

#this script is made for check one host,if it is unreachable,then output result of traceroute can refer to traceroute.txt file.
#want to check the result,please use "tail -n 100 traceroute.txt"
#version 2
#20170614
#!/bin/sh
while [ "1" = "1" ]
do 
ping -c 1 192.168.30.21 > /dev/null
a=$?
if [ $a -eq 1 ]
then 
    echo $a >> ping.txt
    b=$(awk 'END{print NR}' ping.txt)
    if [ $b -eq 5 ]
    then 
        date=` date +%Y%m%d-%k:%M:%S `
        echo "=======start=======" >> traceroute.txt
        echo $date >> traceroute.txt
        traceroute 8.8.8.8 >> traceroute.txt
        c=$(awk 'END{print NR}' traceroute.txt)
        if [ $c -gt 3000 ]
        then
            tail -n 300 > traceroute-temp.txt
            cat traceroute-temp.txt > traceroute.txt
            rm -rf traceroute-temp.txt
        fi
    fi
else
    cat /dev/null > ping.txt
fi
done

脚本说明：ping检测到ip192.168.30.21，连续不通5次就输出traceroute 8.8.8.8的结果到traceroute.txt