bash shell脚本，判断某一网段的主机是否在线，将其统计出来，并将结果保存的相应的文件中

以47.94.215.0/24网段为例，判断该网段内所有主机在线与否，以能ping通视为在线，反之离线。脚本名为ping.sh

将其结果保存至/tmp/ping目录下，在线主机的保存文件为/tmp/ping/uphosts.ttx，离线主机的保存文件为/tmp/ping/downhosts.txt。

 1 #!/bin/bash
 2 #description:Judge online hosts and downhosts,and count
 3 #__Author__:lushenle
 4 #Version:0.0.1
 5 #
 6 ls -d /tmp/ping
 7 if [ $? -eq 0 ];then
 8     ls -f /tmp/ping/uphosts.txt
 9     if [ $? -eq 0 ];then
10         mv /tmp/ping/uphosts.txt{,.bak}
11         touch /tmp/ping/uphosts.txt
12     else
13         touch /tmp/ping/uphosts.txt
14     fi
15     ls -f /tmp/ping/downhosts.txt
16     if [ $? -eq 0 ];then
17         mv /tmp/ping/downhosts.txt{,.bak}
18         touch /tmp/ping/downhosts.txt
19     else
20         touch /tmp/ping/downhosts.txt
21     fi
22 else
23     mkdir -p /tmp/ping/
24     touch /tmp/ping/uphosts.txt
25     touch /tmp/ping/downhosts.txt
26 fi
27 
28 echo "#description:47.94.215.0/24 uphosts." > /tmp/ping/uphosts.txt
29 echo "#description:47.94.215.0/24 downhosts." > /tmp/ping/downhosts.txt
30 
31 net='47.94.215'
32 declare -i i
33 
34 uphosts=0
35 downhosts=0
36 
37 for i in {1..254};do
38     ping -c 1 -w 1 ${net}.${i} &> /dev/null
39     if [ $? -eq 0 ];then
40         echo "${net}.${i} is up." >> /tmp/ping/uphosts.txt
41         let uphosts++
42     else
43         echo "${net}.${i} is down!" >> /tmp/ping/downhosts.txt
44         let downhosts++
45     fi
46 done
47 
48 echo "Uphosts is:$uphosts." >> /tmp/ping/uphosts.txt
49 echo "Downhosts is:$downhosts." >> /tmp/ping/downhosts.txt

~]# bash -n /PATH/TO/ping.sh 　　#检查是否存在语法错误

~]# bash -x /PATH/TO/ping.sh 　　　#查看执行过程