作者：steeven
email: phpme@citiz.net
日期：8/15/2001 9:28:39 PM
掃描500個(gè)IP10秒鐘左右, 一個(gè)IP等待0.3秒
說來慚愧, 我覺得是用java寫的過程編程, 少貼一點(diǎn)僅供參考:
package steeven;

import java.sql.*;
import java.io.*;
import java.util.*;
import java.text.*;
import javax.servlet.http.*;

public class Ip extends Common implements Runnable{

  public String ip;           // IP, 用戶名, 主機(jī)名

  ResultSet list;                 // 分頁顯示的記錄集
  public Ip cur;               // 分頁顯示的當(dāng)前記錄

  static public Hashtable ping = new Hashtable(); //ping 后的結(jié)果集
  static int threadCount = 0;  //當(dāng)前線程的數(shù)量, 防止過多線程摧毀電腦


  public Ip() {}
  public Ip(String ip){
    this.ip=ip;
    Thread r = new Thread(this);
    r.start();
  }

  public static void Ping(String ip) throws Exception{
    //最多30個(gè)線程
    while(threadCount>30)
      Thread.sleep(50);
    threadCount +=1;
    Ip p = new Ip(ip);
  }
  public void PingAll() throws Exception{
    threadCount =0;
    ping = new Hashtable();
    while(next())  //next()對所有局域網(wǎng)Ip放到cur
      Ping(cur.ip);
    //等著所有Ping結(jié)束
    while(threadCount>0)
      Thread.sleep(50);
  }
  public void run(){
    try{
      Process p= Runtime.getRuntime().exec ("ping "+ip+ " -w 300 -n 1");
      InputStreamReader ir = new InputStreamReader(p.getInputStream());
      LineNumberReader input = new LineNumberReader (ir);
      //讀取結(jié)果行
      for (int i=1 ; i<7; i++)
        input.readLine();
      String line= input.readLine();
      
      if (line.length()<17 || line.substring(8,17).equals("timed out"))
        ping.put(ip,new Boolean(false));
      else
        ping.put(ip,new Boolean(true));
      //線程結(jié)束
      threadCount -= 1;
    }catch (IOException e){}
  }
  public static void main(String[] args) throws Exception{
    Ip ip= new Ip();
    ip.PingAll();
    java.util.Enumeration key = ping.keys();
    String k;
    while((k = (String)key.nextElement()) != null)
      System.out.println(k+": "+ping.get(k));
  }
}

1. 利用Ping比較愚蠢, 但是相對簡單些
2. 如果Ping 成功后, 用nbtstat還可以得到主機(jī)名, 當(dāng)前用戶名, MAC地址...一切盡在掌握中  :)