如何將字符型轉成數值？

billjie1

如何將字符型　2.98 轉換成數值型的 　2.98　然後再進行數值計算。
小弟想寫個網絡測試腳本，需要把字符型轉成數值。。現在是無法計算。。。


ping -c 10 $1 >/tmp/nettest.temp
  #extract and anlyze the network infomation from  packet
  local result1=`cat /tmp/nettest.temp|gawk '/packets/{print $6}'|sed s/%//`
  local time_tmp=`cat /tmp/nettest.temp|gawk '/time/{print $7}'`
  local time1=`echo $time_tmp|gawk '/time/{print $2}'|sed s/time=//`
  local time2=`echo $time_tmp|gawk '/time/{print $5}'|sed s/time=//`
  local time3=`echo $time_tmp|gawk '/time/{print $7}'|sed s/time=//`
  local time4=`echo $time_tmp|gawk '/time/{print $9}'|sed s/time=//`
  let time_tmp2=($time1+$time2+$time3+$time4)
  local time_tmp2=$(($time_tmp2/4))






全碼如下：
#!/bin/bash
#This scripts writed by bill.jie
#  if you have any question ,or find some bugs .Please email billjie1@gmail.com ,Thank  You!
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/sbin


#define the variable for server ip address
server1_ip=192.168.130.3
svr2_ip=192.168.130.8
svr3_ip=192.168.130.2
svr4_ip=192.168.130.4
svr5_ip=192.168.130.9
svr6ip=192.168.130.6
mail_ip=192.168.129.2
svr7_ip=172.16.3.254
svr9_ip=172.16.3.1
svr10_ip=10.0.0.254
svr11_ip=192.168.1.2
svr12=172.16.2.254
svr15_ip=192.168.0.18


#capture local host`s ip address
localhostip=`ifconfig eth0|gawk '/addr:/{print $2}'|sed s/addr://`
#argument inspecting
if [ -z "$localhostip" ]
then
   echo "THE local host ip address is null.at `date`">>/var/log/erro_test.log
   #teminal scripts
  exit 2
fi
#test the tcp/ip protocol
lohoresult=`ping -c 4 $localhostip|gawk '/packets/{print $6}'|sed s/%//`

#if  the local host test  failred ,the scripts will terminaled
if [[ ($lohoresult -eq 100)||($lohoresult -gt 60) ]]
then
echo "tcp/ip test failre.at `date`">>/var/log/erro_test.log
#terminate scripte
exit 3
fi

#Next ,check the  gateway
#capture gateway ip address
local_gateway_ip=`route |gawk '/default/{print $2}'`

#At first, check the gatway ip address
if [ -z "$local_gateway_ip" ]
then
  echo "the gateway address is null ,script terminaled.at `date`">>/var/log/erro_test.log
  kill -9 $$
fi

#test gateway
gtresult=`ping -c 10 $local_gateway_ip|gawk '/packets/{print $6}'|sed s/%//`
#scripts will be run as network quality
case $gtresult in
100)
  echo "There is not a way to achieve gateway,scripts will be terminal. at `date`">>/var/log/erro_test.log
  kill -9 $$
  ;;
50)
  echo "The network worked  poorly ,The scripts test will be not correct .at `date`">>/var/log/erro_test.log
  ;;
80)
  echo "The network cannot able to test as poorly quality. at `date`">>/var/log/erro_test.log
  kill -9 $$
  ;;
esac

#define a function to test server and output result

server_test()
{
   if [ -z "$1" ]
    then
       echo "The argument is null,functions terminaled"
       exit 5
   fi
  #capture network packet.
  ping -c 10 $1 >/tmp/nettest.temp
  #extract and anlyze the network infomation from  packet
  local result1=`cat /tmp/nettest.temp|gawk '/packets/{print $6}'|sed s/%//`
  local time_tmp=`cat /tmp/nettest.temp|gawk '/time/{print $7}'`
  local time1=`echo $time_tmp|gawk '/time/{print $2}'|sed s/time=//`
  local time2=`echo $time_tmp|gawk '/time/{print $5}'|sed s/time=//`
  local time3=`echo $time_tmp|gawk '/time/{print $7}'|sed s/time=//`
  local time4=`echo $time_tmp|gawk '/time/{print $9}'|sed s/time=//`
  let time_tmp2=($time1+$time2+$time3+$time4)
  local time_tmp2=$(($time_tmp2/4))

  
#compare just test result with old infomation
  if [[ ($result1 -eq 0)||($result1 -lt 70) ]]
     then
       if [ $time_tmp2 -lt 70 ]
           then
               echo "The $1 is UPline . quality : Good   Average delay : $time_tmp2 ">>/tmp/compare.tmp
           else
               if [ $time_tmp2 -lt 100 ]
                   then
                       echo "The $1 is OK . But quality : badly  Average delay : $time_tmp2">>/tmp/compare.tmp
                      else
                         echo " The $1 is Ok . But quality : poorly  Average delay : $time_tmp2">>/tmp/compare.tmp
               fi
        fi
      else
               case "$1" in
                "$cnrouter_ip")
                  echo "Emergency,The cn router down off ">>/tmp/compare.tmp
                  ;;
                "$twvpndev")
                  echo "Emergency, vpn network with  taiwan  interrupted ">>/tmp/compare.tmp
                  ;;
                "$cnvpndev_ip")
                  echo "Emergency,cn vpn device down off ">>/tmp/compare.tmp
                  ;;
                "$firwall_ip")
                  echo "Emergency,firewall maybe down off ">>/tmp/compare.tmp
                  ;;
                 "$twmail_ip")
                  echo "waring , taitwan mail server may  be down off " >> /tmp/compare.tmp
                 ;;
                 *)
                 echo "The $1 is Downline. quality : zero  Average delay :  null ">>/tmp/compare.tmp
                 ;;
                 esac
  fi
}

Iambitious

bash里面计算float数，只能用bc巴

billjie1

謝謝樓上的兄弟，我再去看看！