Shell script for detecting network segment online hosts

Job Four:

Write a script:

Implement Ping Class C network segment, Class B network segment and all hosts in Class A network segment;

The network segment address lets the user input, moreover uses the script to judge the network segment type;

#!/bin/bash #Author: MOS #Script name:funPing.sh #Date & time:2012-10-09/21:53:09 #Version: 1.0.1 #Descri Ption: # #定义C类网段处理函数 Net_c () {#定义统计不在线IP数量的变量 declare-i fail=0 #生成C类网的最后位IP, loop ping for I in ' seq 1 254 ';d o #ping只发送一个, just wait 1 seconds, get all the information and throw it away, just go logical value if PING-C 1-w 1 $ $i &>/dev/null; then echo  
"Online $ $i" Else let fail++ fi do echo "No online PC, number is $Fail"} Net_b () {#截取B类网的网段 bip= ' echo $1|cut-d '. '-f1-2 ' declare-i fail=0 #循环生成B类网第三段 for i in ' seq 0 254 '; Do res= "$Bip. $i" #循环生成B类网第四段 for R in ' SEQ 1 254 ';d o if ping-c 1-w 1 $Res. $r &>/de  
        V/null then echo "Online $Res. $r" Else let fail++ fi Done the echo "No Online PC, number is $Fail"} net_a () {bip= ' echo $1|cut-d '. '-f1 ' Decl Are-i fail=0 #生成A类网的第Two paragraphs, third and fourth paragraphs, and so on for I in ' seq 0 254 ';d o res= ' $Bip. $i "for R in" Seq 0 254 ';d o res1= ' $Res.     
                    $r "for L in ' SEQ 1 254 ';d o if ping-c 1-w 1 $Res 1. $l &>/dev/null; then  
            echo "Online $Res 1. $l" Else let fail++ fi Done does echo "No Online PC, number is $Fail"} read-p "please input subset:" Ip #判断输入IP段 Whether the fall is legal if [[$Ip =~ ^ ([2-9]|[ 1-9][0-9]|1[0-9][0-9]|2[01][0-9]|22[0-3]) \. ([0-9]| [1-9] [0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4]) \. ([0-9]| [1-9] [0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4]) $]];then #合法, remove the first field, which type of net mask= ' echo ' $Ip ' |cut-d '.-f1 #如果是A类网  
    A function, and so on [$Mask-lt 128] && net_a $Ip [$Mask-lt 192-a $Mask-gt 127] && net_b $Ip [$Mask-gt 191] && net_c $Ip Else #如果输入IP错误, the error message is as follows Echo "error! $Ip invalid. "Fi

If you want to use the above code, be cautious ... In particular, Class A and class B nets ... 255*255*255 The resource cost, you ponder .... Well, if it's only for testing, you can output the results to a file, put it in the background, or just test a specific IP, you can change the number of SEQ in the For loop, modify it, is no problem ....