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bash脚本编程之十四 信号捕捉及系统管理之任务计划-ping脚本

发布时间：2018-10-21 14:50:25编辑：雪饮阅读（）

(1)trap单命令

ping脚本：

[root@localhost ~]# cat ./ping.sh

#!/bin/bash

#

NET=192.168.43

FILE=`mktemp /tmp/file.XXXX`

clearup(){

 echo "quit..."

 rm -rf $FILE

 exit 1

}

 

trap 'clearup' INT

 

for I in {160..180};do

 if ping -c 1 -W 1 $NET.$I &> /dev/null;then

    echo "$NET.$I is up." | tee >> $FILE

  else

    echo "$NET.$I is down."

  fi

done

[root@localhost ~]# ./ping.sh

192.168.43.160 is down.

192.168.43.161 is down.

192.168.43.162 is down.

192.168.43.163 is down.

192.168.43.164 is down.

192.168.43.165 is down.

192.168.43.166 is down.

192.168.43.167 is down.

192.168.43.168 is down.

192.168.43.169 is down.

192.168.43.170 is down.

192.168.43.172 is down.

192.168.43.173 is down.

192.168.43.174 is down.

quit...

解析：

ping：

 -c：ping的次数

 -W:超时时间

tee：可以将标准输出重定向到一个文件中的同时显示到标准输出中，但若用>>则无法显示到标准输出上，直接后跟一个文件参数反而可以。

(2)trap多命令：

当trap多个脚本时用分号来作为分隔符。

脚本：

[root@localhost ~]# cat ./ping.sh

#!/bin/bash

#

NET=192.168.43

FILE=`mktemp /tmp/file.XXXX`

 

trap 'echo "quit.";exit 1' INT

 

for I in {160..180};do

 if ping -c 1 -W 1 $NET.$I &> /dev/null;then

    echo "$NET.$I is up." | tee >> $FILE

  else

    echo "$NET.$I is down."

  fi

done